We have forever drummed into athletes that warming up properly and training smart can keep injuries away and improve performance. But most of the research backing that advice has been scattered, looking at warm-ups, strength work, or recovery in isolation rather than as one connected system. This review pulls together decades of work on neuromuscular warm-ups (like the well-known FIFA 11+ program), eccentric hamstring training, dynamic stretching, and load management to see how these pieces fit together across the full arc from warm-up to recovery. The goal was to figure out what actually holds up across the evidence pool, and what practical patterns coaches and trainers can lean on with confidence.

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Aims and methods

The researchers set out to map exercise-based strategies across the entire training and competition cycle, not just one phase. Instead of running a meta-analysis, which works best when studies are similar enough to combine into one number, the team did a structured qualitative synthesis. They pulled together 40 studies, a mix of randomised trials, meta-analyses, systematic reviews, and observational research, all focused on athletes doing some kind of exercise-based intervention tied to injury prevention or performance. Two reviewers screened and extracted everything independently, checked study quality using standard tools suited to each design, and grouped findings by intervention type and population rather than averaging them together.

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What they found

There were a few obvious patterns. Structured neuromuscular warm-up programs, the kind that blend balance work, landing mechanics, and short bursts of speed, were consistently tied to fewer lower-extremity injuries, especially at the ankle and knee. These same programs often came with a performance bonus too, including better jump height and faster sprint times, suggesting the prevention and performance benefits are not separate; they are intertwined.

Eccentric hamstring training, often delivered through the Nordic hamstring exercise, showed a similar dual benefit. Athletes who did this work regularly tended to have fewer hamstring strains, including fewer repeat injuries, alongside gains in eccentric strength and longer muscle fascicles, a structural change thought to help the muscle absorb force more safely.

Dynamic stretching held up well as a warm-up tool, generally supporting or improving explosive movement, while prolonged static stretching tended to blunt performance right afterwards. This lines up with what most current coaching guidance already recommends.

Load management mattered too. Programs that gradually built training volume, rather than spiking intensity, were associated with fewer strain injuries. The takeaway here is one of a common-sense approach to managing load for your athletes, not just the outcomes you’re hoping to peak for.

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Most exercise advice focuses on cardio, but this study turns the spotlight on strength training and asks:

‘‘How much of it helps you live longer, and is there a point where more stops making a difference?’’

Researchers pulled data from three long-running health studies that followed people for up to three decades, giving them a look at how resistance training habits connect to risk of death over time. Because the majority of us aren't training for a competition, we just want to know what's worth our time. This study dove right in.

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Aims and Methods

The researchers wanted to understand whether resistance training, on its own or combined with aerobic exercise, was linked to lower mortality, and whether that link differed depending on the cause of death. They drew on data from the Health Professionals Follow-up Study and both Nurses’ Health Studies, covering over 147,000 men and women. Every two years, participants reported how much time they spent on strength training and aerobic activity. Strength training included weights and bodyweight movements like push-ups, squats, and lunges. Aerobic activity covered things like brisk walking, running, swimming, and cycling. Researchers then tracked who died over the following decades and from what cause, then adjusted for other lifestyle factors that could muddy the results.

Results

People who did about 90 to 120 minutes of strength training per week had a noticeably lower risk of death overall, with the strongest drops showing up for cardiovascular and neurological disease deaths specifically. Going beyond 120 minutes a week didn’t add any extra benefit, suggesting this isn’t a more-is-better situation.

Interestingly, the relationship wasn’t the same for every cause of death. For cancer-related deaths, the benefit showed up at much smaller amounts of strength training, even just a few minutes a week made a measurable difference, and the benefit didn’t keep climbing with more volume.

Aerobic exercise on its own remained a powerful factor, and combining high amounts of aerobic activity with a moderate dose of strength training produced the lowest mortality risk of any group studied. At the very highest levels of aerobic activity, the benefit was so strong that the amount of strength training someone did almost stopped mattering.

It’s worth noting that this was an observational study. People weren’t randomly assigned to exercise groups, so the findings show a strong association rather than definitive proof of cause and effect. The researchers also relied on self-reported exercise habits and didn’t capture things like workout intensity or duration of individual sessions, which leaves some open questions.

Practical Takeaways

If you’re trying to build a routine around what the evidence supports, here’s what we can tell you. You don’t need to spend hours daily in the gym to get a meaningful longevity benefit from strength training. Somewhere around 90 to 120 minutes a week, or roughly 15 to 20 minutes most days, appears to capture most of the upside, especially for heart and brain-related health. If your main concern is cancer risk specifically, even a small, consistent amount seems to help. And if you’re already doing a solid amount of cardio, adding even modest strength training on top still seems to move the needle. The bigger picture message is that both types of movement complement each other, and a tiny bit of both can add up.

Reference

Zhang Y, Lee DH, Rezende LFM, et al. Long-term resistance training with all-cause and cause-specific mortality: assessing dose-response and joint associations with aerobic physical activity. British Journal of Sports Medicine 2026;60:874-883.

Anyone who follows training science has probably heard how training at "long muscle lengths," the idea that lifting through a deep stretch position grows muscle better than training through a shorter range. This study, out of Florida Atlantic University's Muscle Physiology Lab, put that idea to a direct test in the biceps. Researchers wanted to know if training only at long muscle lengths actually beats a mixed approach that combines long and short positions. This matters because most lifters do not train one single range of motion all day. They use a variety of exercises and angles. If mixing lengths is just as good as staying long, that changes how rigid people need to be when programming their curls.

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Aims and Methods

The researchers recruited seven recreationally trained lifters and used a within-participant design, meaning each person’s two arms were randomly assigned to different conditions, then the whole thing was repeated a second time after a washout period. This gave them statistical power similar to that of fourteen separate participants.

One arm is trained using only a lengthened cable curl, performed from a seated position with the shoulder extended. This is the LONG condition. The other arm split its training volume evenly between that same lengthened curl and a shortened cable curl performed standing with the shoulder flexed. This is the MIXED condition. Total weekly volume was matched between arms.

Over eight weeks, researchers tracked muscle size using ultrasound, dynamic and isometric strength, arm circumference, and how sore and fatigued each arm felt after sessions. Instead of simple yes or no statistics, they used a Bayesian approach that estimates the probability and size of an effect, with researchers and a glossary at the end if you want to dig into how this style of analysis works.

Results

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When lifters or coaches talk about "feeling the muscle work" instead of just moving the weight, what they’re most often referring to is “the mind-muscle connection”, or MMC. The idea is simple. When you deliberately focus your attention on a specific muscle during a lift, trying to ensure you actually feel that particular muscle working, that muscle has greater activity than it otherwise would. Most of the research backing this up has come from people who already lift weights regularly. This new study from Sunmoon University asked a more practical question for the average gym-goer: Does this internal focus cue still work if you've never trained before, and does focusing on one muscle quietly drag other muscles along with it, or even take away from muscles you didn't mean to involve?

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Aims and Methods

The researchers recruited healthy young adults with no resistance training background and had them perform a machine-based shoulder press using a light to moderate load. Each person came in on three separate days and tried three different mental approaches: pressing with no particular focus at all, pressing while concentrating on their deltoid (the shoulder muscle), and pressing while concentrating on their triceps. Surface electrodes tracked the electrical activity of the deltoid, the triceps, and the upper trapezius, which is a muscle near the neck and shoulder blade that often gets dragged into upper-body pushing movements as a stabiliser. The machine was used specifically because it keeps the movement path locked in, removing a lot of the balancing and stabilising work your body would otherwise do with free weights, which makes it easier to isolate what attention alone is doing.

Results

The shift in attention changed things clearly and consistently. When people focused on their deltoid, deltoid activity rose. When they focused on their triceps, triceps activity rose. Each muscle responded specifically to being the target of attention, not to the exercise in general. The upper trapezius, which wasn’t the focus in either condition, stayed steady no matter what the person was thinking about. It didn’t ramp up when attention was elsewhere, which suggests the body wasn’t compensating or recruiting extra stabilising effort just because someone was concentrating harder on the movement overall.

Practical Takeaways

For someone newer to resistance training, this suggests that simply directing your attention to the muscle you’re trying to train, rather than just moving through the motion, can meaningfully change how hard that muscle works, even on your very first attempts at the lift. You don’t need years of training experience for this cue to matter. It also suggests that this focus is genuinely targeted rather than a side effect of generally trying harder, since the muscle that wasn’t part of the instruction didn’t budge. Because this was tested in a single session on a machine using a moderate load, it tells us about activation in the moment rather than guaranteed long-term muscle growth or strength gains, and it’s unclear whether the same focused effect would hold up under heavier loads or in free-weight movements where balance and stability take up more of your attention. Still, for beginners working on a machine press, using an internal focus of attention seems like a reasonable and low-risk thing to try as you learn to navigate this new

Reference

Kim D, Woo J, Lee S, Jung J, Lee D, Hong J, Yu J, Kim J, Nam Y, Jeon J. Effects of Mind–Muscle Connection on Muscle Activity During Machine-Based Shoulder Press in Untrained Individuals. Journal of Clinical Medicine. 2026; 15(10):3925. https://doi.org/10.3390/jcm15103925

A 24-week trial on elite track and field athletes found that complex training and contrast training both improve explosive power, but they do it in different ways and for different purposes. Complex training built more jump height and eccentric strength. Contrast training made athletes faster off the ground. These findings give coaches a clear, evidence-based framework for choosing the right method based on an athlete's strengths and their sport's demands. Let’s dive in.

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Aim

Researchers from Jimei University in China wanted to know which of two popular training methods, complex training or contrast training, was better for building lower-body explosive power and eccentric strength in elite athletes over the long term. They also examined whether arm swing plays a meaningful role in jump performance and whether eccentric strength could predict jump height.

Methods

Forty-five national-level male track and field athletes were randomly split into three equal groups of 15: a complex training group, a contrast training group, and a control group. All groups trained three 90-minute sessions per week for 24 weeks.

The complex training group paired heavy resistance work with plyometrics using short 1-3 minute rest periods between exercises, designed to take advantage of postactivation potentiation (PAP), the brief window after heavy lifting where the neuromuscular system is primed for explosive output.

The contrast training group used a similar pairing of heavy and explosive work, but with much longer rest periods of 4-10 minutes between exercises. This design targets postactivation performance enhancement (PAPE), a more sustained improvement in voluntary performance after maximal loading.

The control group followed the university’s standard strength and conditioning program, including traditional squats, sled sprints, and core work.

Jump performance was tested at baseline, week 12, and week 24 using a 3D force plate. Athletes were tested in both arm-swing and no-arm-swing conditions to isolate how much the upper body contributes to jump mechanics.

Results

Both training methods produced meaningful gains, but there were important differences.

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Stronger legs mean fewer injuries. That is the finding of a new study on elite sixes lacrosse players, and with the sport making its Olympic debut at the 2028 Los Angeles Games, the timing could not be more relevant.

Researchers from the University of Salford tracked 19 men from the British national sixes lacrosse squad over nine months, through training sessions, European tournaments, a US training camp, and the World Games. Before it all started, every player completed an isometric mid-thigh pull (IMTP) test to measure lower limb strength relative to their body weight. Over the following nine months, every injury was logged by the team physiotherapist.

The question: Does being stronger in the legs protect players from getting hurt?

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What They Found

Players who produced more force relative to their body weight on the IMTP were significantly less likely to sustain lower-limb injuries, both noncontact injuries (think hamstring strains, ligament sprains) and overload injuries (gradual-onset problems like tendinopathies).

For every 1 N/kg increase in relative strength, the risk of a noncontact injury dropped by 67% and the risk of an overload injury dropped by 33%. That is a meaningful protective effect.

The data also pointed to specific strength targets. Players who hit at least 31.3 N/kg on the IMTP saw roughly an 80% reduction in noncontact injury risk. Those who reached 28.7 N/kg saw around a 45% reduction in overload injury risk. The average score across the squad was 28.9 N/kg, meaning most players were sitting right at or below the safer threshold.

Six players sustained noncontact injuries. Nine sustained overload injuries. The injured players consistently showed lower relative strength scores than those who stayed healthy.

Aim and Methods

The study was prospective, meaning researchers measured strength first and then waited to see who got hurt rather than working backwards. All 19 players performed three IMTP trials on portable force plates at the start of the nine-month competition period. Lifting straps were used so grip strength would not be a limiting factor.

Injuries were classified by mechanism: noncontact (no external contact involved) or overload (gradual onset, no single event). All injury data were collected and assessed by the lead physiotherapist in accordance with international injury surveillance standards.

Bayesian statistical methods were used to analyse the relationship between strength and injury, with odds ratios calculated to quantify the protective effect.

Practical Takeaways

Any strength and conditioning coach worth their salt knows that getting stronger helps.

The researchers recommend targeting a relative net peak force above 31.3 N/kg on the IMTP, which covers protection against both injury types. For a player weighing 89 kg, that means producing roughly 2,786 N of net force, which is genuinely demanding for amateur athletes who are largely self-funded and training in decentralised programs without the resources of professional sport.

The squad in this study averaged below that threshold, which is worth noting. These are elite athletes competing at the highest level of their sport internationally, but without professional structures around them, developing and maintaining adequate strength is a real challenge that practitioners need to plan creatively around.

Beyond injury prevention, building lower limb strength is also known to improve sprint speed, acceleration, deceleration, and change of direction, all of which are critical in the high-intensity format of sixes lacrosse.

One important gap the authors flag: this study only included male athletes. Female players face higher rates of ACL injury in lacrosse, and with women’s sixes also heading to the 2028 Olympics, replicating this research in female squads should be a priority.

Reference

Ripley, Nicholas Joel; Collier, Matthew; Fahey, Jack T.; Comfort, Paul. Protective Effect of Lower Limb Strength on Lower Limb Injuries Within International Sixes Lacrosse Players: A Nine-Month Prospective Study. Journal of Strength and Conditioning Research ():10.1519/JSC.0000000000005476, June 4, 2026. | DOI: 10.1519/JSC.0000000000005476

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

Researchers at University College Cork have found that drinking coffee regularly changes the gut microbiome in specific, measurable ways, and those changes are linked to how you think, feel, and behave. The study, published in Nature Communications, also found that coffee drinkers score higher on impulsivity and emotional reactivity than non-drinkers, and that taking a break from coffee can actually improve memory and reduce those behavioural traits. Not only that, decaffeinated coffee produced its own distinct set of effects, suggesting the hundreds of other compounds in coffee also play a real role.

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Aim

The study set out to examine how coffee consumption affects the gut-brain axis — the two-way communication network between the gut microbiome and the brain. Researchers wanted to understand what happens to the microbiome, metabolism, cognition, and mood when people drink coffee, stop drinking it, and then start again. Importantly, they wanted to separate the effects of caffeine from those of coffee as a whole.

Methods

62 healthy adults aged 30 to 50 living in Ireland were recruited. 31 were moderate coffee drinkers (3 to 5 cups per day) and 31 were non-coffee drinkers. The study ran in three phases. First, both groups were compared at baseline. Then coffee drinkers stopped drinking coffee for two weeks. After that, they were randomly assigned to drink either caffeinated or decaffeinated instant coffee for three weeks.

Horrible conditions.

Researchers collected stool, urine, blood, and saliva samples at each stage. They used shotgun metagenomics to analyse the gut microbiome in detail, alongside both targeted and untargeted metabolomics to map the chemical changes happening in the gut and body. Participants also completed a battery of cognitive tests and questionnaires covering stress, anxiety, depression, sleep, impulsivity, and emotional reactivity throughout.

Results

Behaviour and cognition

Coffee drinkers scored higher on impulsivity and emotional reactivity compared to non-coffee drinkers at baseline. After two weeks without coffee, those scores dropped significantly. When coffee was reintroduced, both caffeinated and decaffeinated versions reduced impulsivity and perceived stress. Only caffeinated coffee reduced anxiety and psychological distress. Decaffeinated coffee improved memory performance, sleep quality, and physical activity levels. Caffeinated coffee improved attention and cognitive performance on the PASAT test.

During the two-week washout, withdrawal symptoms were elevated in the first few days but dropped by day four. Fatigue decreased, and energy levels rose across the withdrawal period.

Gut microbiome

Coffee drinkers had higher levels of Cryptobacterium curtum and Eggertheilla species in their gut compared to non-drinkers. These species dropped when coffee was removed and responded again when coffee was reintroduced, regardless of whether it contained caffeine. Overall gut microbial diversity differed between coffee drinkers and non-drinkers, but abstaining from coffee did not significantly change diversity levels. The effects were strain-specific rather than broad.

Metabolites

Coffee drinkers had higher faecal levels of theophylline, caffeine, and hippuric acid, and lower levels of indole-3-propionic acid (IPA), indole-3-carboxyaldehyde (ICA), and GABA. IPA has been linked to improved cognition, and ICA plays a role in gut barrier integrity, so their reduction in coffee drinkers is worth noting. After the washout period, most of those metabolite levels shifted toward levels seen in non-coffee drinkers. Reintroducing caffeine restored caffeine-related metabolites, while (poly)phenol-related metabolites increased with both caffeinated and decaffeinated coffee.

Inflammation and immune response

Coffee drinkers had lower levels of the inflammatory marker CRP and higher levels of the anti-inflammatory cytokine IL-10 compared to non-drinkers. After two weeks without coffee, CRP and TNF-alpha increased, suggesting coffee may have a protective anti-inflammatory role. Both caffeinated and decaffeinated coffee reduced LPS-stimulated IL-6 secretion upon reintroduction.

Blood pressure

Coffee drinkers showed a significant decrease in systolic and diastolic blood pressure during the two-week abstinence period. When caffeine was reintroduced, systolic blood pressure was lower compared to the decaffeinated group.

The integrated picture

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Our older adults don’t need long, high-volume gym sessions to move better and stay independent. This large 2024 review of 151 trials found that low weekly resistance training volume was enough to significantly improve walking, functional tests, lean mass and muscle size in healthy older adults, while higher volume was mainly needed to squeeze out extra strength gains. The takeaway is that for older adults, a small amount of well-structured resistance training goes a long way for healthy ageing.

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Aim

The researchers wanted to find out how much weekly resistance training volume works best for older adults to improve:

• Physical function (walking tests and “get up and go” performance)

• Lean body mass

• Lower-body muscle size

• Lower-body muscle strength

They also checked whether the effects changed based on:

• Program duration (short term under 20 weeks vs 20 weeks or longer)

• Physical health status (physically healthy, physically impaired, or mixed)

Methods

This study was a systematic review and network meta-analysis of randomised controlled trials in adults aged 60 and older. It only included supervised resistance training programs.

Programs were split into three groups based on weekly training volume, calculated as frequency × number of exercises × number of sets:

• Low-volume resistance training (LVRT)

• Moderate-volume resistance training (MVRT)

• High-volume resistance training (HVRT)

The main outcomes were:

• Physical function

  • Timed Up and Go

  • 6-minute walk test

  • Fast walking speed

• Muscle mass and size

  • Lean body mass

  • Lower-body muscle hypertrophy

• Strength

  • One-repetition maximum (1RM) knee extension and leg press

  • Isometric strength

  • Isokinetic torque

A random-effects network meta-analysis was used to compare the different training volumes, even when the original trials did not directly compare all three.

Results

The review included 161 articles covering 151 trials and a total of 6,306 older adults.

Low-volume resistance training:

• Was the most effective for improving Timed Up and Go performance

• Produced the largest gains in the 6-minute walk test

• Led to clear increases in lean body mass

• Produced meaningful lower-body muscle hypertrophy

Moderate and high-volume resistance training:

• Were superior for boosting lower-limb strength compared with low volume

• High volume, in particular, was the only approach that clearly improved fast walking speed

Program duration did not meaningfully change the pattern of results. The benefits of low volume and the strength advantage of higher volume were similar in both shorter and longer programs. Most of the evidence came from physically healthy older adults, and there was not enough data to draw strong conclusions for those who were physically impaired.

Takeaways

For healthy older adults, the key practical points are:

• You do not need high weekly training volume to improve function

  • Low volume was enough to improve key markers of independence, such as getting up from a chair, turning, and walking for 6 minutes

• Low volume is also enough to build lean mass and increase lower-body muscle size

• If the main goal is to get as strong as possible, especially in leg press or knee extension, then moderate to high weekly training volume works better

• The benefits of low-volume training appeared regardless of whether the program lasted less than 20 weeks or continued for 20 weeks or more

• For physically impaired older adults, caution is needed because the evidence base is much smaller

In practice, this supports using low-volume resistance training as a default starting point for healthy older adults who want to move better, stay independent, and build or maintain muscle. Higher volume can then be layered on for those who tolerate training well and have specific strength goals.

Wrap-up

This review reinforces that “minimum effective dose” resistance training is a realistic and effective strategy for healthy older adults. Low-volume programs can deliver meaningful improvements in function, lean mass, and muscle size without long, demanding sessions, while higher volume is mainly needed for maximal strength gains.

Reference

Radaelli, R., Rech, A., Molinari, T. et al. Effects of Resistance Training Volume on Physical Function, Lean Body Mass and Lower-Body Muscle Hypertrophy and Strength in Older Adults: A Systematic Review and Network Meta-analysis of 151 Randomised Trials. Sports Med 55, 167–192 (2025). https://doi.org/10.1007/s40279-024-02123-z

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

A new randomised controlled trial says no. Researchers from the University of Glasgow put healthy adults through six weeks of training at either 6–10 am or 4–8 pm and measured muscle size, muscle strength, and insulin sensitivity before and after. Both groups improved, but neither group improved more than the other. The verdict: train when you can.

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What They Studied

The debate around exercise timing has been fuelled by the idea that the body’s internal clock, circadian rhythms, might make certain times of day better for building muscle or improving metabolic health. Evening exercise has long been theorised to have an edge for insulin sensitivity, and strength has been known to peak in the late afternoon. This trial was designed to test those theories in healthy adults without diabetes.

How It Was Done

Thirty-six healthy adults, averaging 30 years old and a BMI of around 28 kg/m², were split into three groups: morning training, evening training, and a control group that did nothing structured. Both training groups performed the same eight-exercise resistance training program three times per week for six weeks, working at 80% of their one-rep max to failure each set. The program included bench press, bicep curl, lat pulldown, overhead press, lateral raise, leg extension, leg curl, and calf raise. Attendance was 100% across both groups.

Muscle size was measured using ultrasound on the vastus lateralis (the outer quad muscle). Strength was assessed via knee extensor torque and one-rep max. Insulin sensitivity was tested using an oral glucose tolerance test. Participants also wore continuous glucose monitors for several weeks to track real-world blood sugar responses.

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We spend up to 90% of our time indoors, bathed in artificial light. A new study out of Maastricht University has found that simply swapping that artificial office lighting for natural daylight through a window improved blood sugar control and shifted the body to burn more fat in people with type 2 diabetes. The findings were published in Cell Metabolism in January 2026.

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Aim

The researchers wanted to know whether natural daylight during typical office hours, as opposed to standard artificial lighting, would improve glucose control and whole-body metabolism in people with type 2 diabetes (T2D). The study also aimed to understand why, by looking at changes in skeletal muscle clock genes, circulating metabolites, lipids, and immune cell gene expression.

Methods

Thirteen adults with T2D (8 women, 5 men; average age 70 years; average BMI 30) took part in a randomised crossover trial. Each person completed two 4.5-day stints in a research facility, one under natural daylight through wide windows and one under constant artificial lighting set to around 300 lux. The two periods were separated by at least four weeks

Office hours ran from 8 am to 5 pm. Meals, physical activity, sleep schedules, and evening light exposure were standardised and kept identical across both conditions. Participants wore blue-light-blocking glasses whenever they left their assigned room, ensuring that those in the artificial light condition were never exposed to the short wavelengths of natural daylight the human circadian system is most sensitive to.

Continuous glucose monitoring (CGM) ran across the entire 4.5 days. On day 4, researchers used indirect calorimetry to measure how the body burned fuel. Skeletal muscle biopsies, blood samples, and saliva were also collected for deeper molecular analysis.

Results

Glucose control improved under natural daylight. While average glucose levels across the 4.5 days were not statistically different between the two conditions, participants spent significantly more time in the normal glucose range (4.4 to 7.2 mmol/L) under natural light compared to artificial light (51% vs. 43%). The daily swings in baseline glucose levels were also smaller under natural daylight, and those smaller swings were directly linked to more time in the normal range.

The body burned more fat. Under natural daylight, participants showed lower carbohydrate oxidation and higher fat oxidation throughout the waking day, particularly around midday. This pattern held up during a standardised mixed meal test the following morning, with free fatty acid levels also trending higher under natural light.

The muscle clock shifted. Muscle biopsies showed higher expression of the clock genes Per1 and Cry1 after natural light exposure. When muscle cells grown from those biopsies were tested in a lab, their internal circadian rhythm was phase-advanced by about 45 minutes, a sign that the muscle’s internal clock had been genuinely reset by the light environment rather than just temporarily altered.

Melatonin rose higher in the evening. While the timing of melatonin onset did not differ between conditions, melatonin levels in the two hours before bed were meaningfully higher under natural light. This suggests the body’s sleep-wake signal was stronger after a day in natural daylight.

Multi-omic signatures shifted, too. Blood metabolite and lipid profiles also differed between conditions. Levels of ceramides and cholesterol esters, both elevated in T2D and associated with poorer metabolic health, trended lower under natural light. Lipid species linked to better insulin sensitivity were higher. These molecular signals are broadly consistent with the improvements in glucose control and fat burning observed.

Blood pressure, heart rate, core body temperature, physical activity, sleep quality, and mood scores did not differ between conditions, ruling out these factors as drivers of the metabolic differences.

Takeaways

The sample was small. Only 13 participants completed the trial, all older adults (average age 70), so caution is warranted before generalising these findings to younger or broader populations. The researchers note that longer trials are needed to confirm whether these effects hold over weeks or months.

• Getting natural daylight through a window during work hours improved time in the normal blood sugar range in people with T2D, without any changes to diet, medication, or exercise

• The body shifted toward burning more fat during the day under natural light conditions

• The skeletal muscle’s internal clock was measurably reset by daylight, pointing to a plausible biological mechanism

• Evening melatonin levels were higher after daytime natural light exposure, which may benefit sleep quality

• Artificial office lighting set to a typical 300 lux produced measurably worse metabolic outcomes than natural daylight in this group

• The built environment, specifically whether your workplace has windows, may matter more for metabolic health than previously recognised

Reference

Harmsen, J-F., Habets, I., Biancolin, A.D., Lesniewska, A., Phillips, N.E., Metz, L., Sanchez-Avila, J., Kotte, M., Timmermans, M., Hashim, D., de Kam, S.S., Schaart, G., Jörgensen, J.A., Gemmink, A., Moonen-Kornips, E., Doligkeit, D., van de Weijer, T., Buitinga, M., Haans, F., De Lorenzo, R., Pallubinsky, H., Gordijn, M.C.M., Collet, T-H., Kramer, A., Schrauwen, P., Dibner, C., & Hoeks, J. (2026). Natural daylight during office hours improves glucose control and whole-body substrate metabolism. Cell Metabolism, 38, 65–81. https://doi.org/10.1016/j.cmet.2025.11.006

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

A new review published in Sport Sciences for Health set out to explore if and how men and women might respond differently to strength training. The short answer is less than most people assume. While men start with more muscle and produce more absolute force, when both sexes train the same way, they gain strength and muscle at roughly the same relative rate. The review also found that women tend to outlast men in endurance-based efforts, and that the gap in explosive power is larger than the gap in raw strength. For coaches and athletes, the takeaway is that programs should not be based on sex alone and should be based on the individual needs. Let’s dive in.

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Aim

Researchers from the Neuromuscular Research Lab at the University of Lisbon conducted a narrative review of the current literature on sex-based differences in resistance training (RT) adaptations. They focused on four key areas: maximal strength, muscle hypertrophy, speed strength, and strength endurance. A semi-structured search of PubMed, Scopus, and Web of Science was conducted, with preference given to studies published between 2020 and 2025.

Methods

This was a narrative review, not a controlled trial. The authors searched sport science databases using terms like “sex differences,” “resistance training,” “muscle hypertrophy,” “speed strength,” and “strength endurance.” Only peer-reviewed studies conducted on human adults and published in English were included. Older studies were pulled in through reference screening of more recent papers.

Results

Maximal Strength

Men produce significantly more absolute strength than women across most exercises. In bench press and chest press, female strength sits around 40 to 55% of male values. In the squat and leg press, that figure rises to around 60 to 65%. The gap is wider for upper-body movements than for lower-body. Among competitive powerlifters, strength-to-bodyweight ratios also favour men, though the margin is smaller in the lower body. The key driver of this gap is greater muscle mass in men, not differences in how well the nervous system activates muscle. Both sexes voluntarily activate their muscles to a similar degree.

When you account for body composition, particularly lean mass, the lower-body strength gap between male and female athletes largely disappears. The upper body gap persists even after that adjustment.

The gap in strength is also smaller during eccentric contractions compared to concentric. Women tend to show a higher eccentric-to-concentric strength ratio, particularly in upper body exercises like the military press and bench press.

Relative Strength Gains

Despite the baseline differences, both men and women improve their relative strength at comparable rates following RT. Percentage gains in maximal strength are largely similar. Some data suggest women may have a slight edge in upper-body relative strength gains, though this finding comes with caveats around training status and study design.

Muscle Hypertrophy

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Resistance training is the best exercise for overall brain health in older adults, beating out aerobic exercise, Tai Chi-style training, and HIIT, according to a new network meta-analysis. But the full picture shows each exercise type has its own cognitive sweet spot.

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The Study

Researchers from Nanjing Normal University pooled data from 37 randomised controlled trials (RCTs) covering 2,585 older adults to compare how different types of exercise affect cognitive function. Using a network meta-analysis, they were able to rank not just exercise types that had been directly compared against each other, but also make indirect comparisons across the full body of evidence.

The exercise types tested were: resistance training, aerobic exercise, high-intensity interval training (HIIT), physical and mental training (like Tai Chi and yoga), and multimodal exercise. Participants were healthy adults aged 55 and older, with an average age of 69.4 years, drawn from 13 countries, including Australia, the US, China, and Italy.

Methods

The research team searched PubMed, Web of Science, and several other databases for studies published up to May 2024. Only randomised controlled trials were included to ensure the highest level of evidence.

Cognitive outcomes were measured across five areas: overall cognitive function, inhibitory control, task-switching ability, working memory, and memory function. Tests used included the Montreal Cognitive Assessment, the Stroop Test, Trail Making Test, and the N-back Test.

Results

The big takeaway: resistance training ranked first for overall cognitive function, with an 83% probability of being the most effective exercise type. It also topped the rankings for inhibitory control.

For memory, aerobic exercise came out on top, with a ranking probability of 80%. Physical and mental training, such as Tai Chi and yoga, was the standout for task-switching ability and working memory, with an 84% probability of being the best for working memory. Those working memory results did not reach statistical significance compared to controls, so they warrant some caution.

Practical Takeaways

Based on subgroup analyses, the researchers identified optimal training prescriptions for each exercise type.

Resistance training (overall brain health and inhibitory control):

• 12 weeks

• 2 to 3 sessions per week

• 45 minutes per session

Aerobic exercise (memory):

• 21 weeks

• 2 sessions per week

• 60 minutes per session

Physical and mental training, e.g. Tai Chi or yoga (task-switching and working memory):

• 12 weeks

• 3 sessions per week

• 60 minutes per session

No single exercise type does everything. If protecting memory is the goal, aerobic exercise is the pick. For overall cognitive sharpness and attention control, resistance training leads. For mental flexibility and working memory, mind-body training is the strongest option.

The researchers also note that Tai Chi-style practices may be easier to promote in older populations due to their lower intensity and strong safety profile, while HIIT carries more feasibility barriers for this age group.

Limitations

Most included studies were rated moderate risk of bias, with only one rated low risk and seven rated high risk. Different cognitive assessment tools were used across studies, which introduces variability. Long-term follow-up data was also scarce, so it remains unclear how long the cognitive benefits last after training ends.

Reference

Zhang, J., Ye, W., Li, W., Zhang, F., & Wu, Z. (2025). Comparative efficacy of exercise interventions for cognitive health in older adults: A network meta-analysis. Experimental Gerontology, 206, 112768. https://doi.org/10.1016/j.exger.2025.112768

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

A professional bodybuilder preparing for the Mr Olympia loses muscle thickness across every major muscle group during his cut, and new ultrasound data from Italian researchers shows that muscle quality also takes a hit, even as body fat barely moves.

Researchers from the University of Bologna tracked a 38-year-old IFBB Pro League Open bodybuilder (128.7 kg, 176 cm, 25 years of training experience, three-time Mr Olympia competitor) through his bulking phase and into his cutting phase, 10 days before competition. They measured muscle thickness and corrected echo intensity (cEI) — a measure of muscle quality — via ultrasound across nine muscle groups, while also analysing his full food and training logs.

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The Setup

The athlete was assessed during his bulking phase (week 8 of 14) in February 2025, and again during his cutting phase (week 9 of 11) in June 2025.

The training program remained nearly identical across both phases: five training days per week, the same split, the same set-and-rep structure, with every set taken to technical failure. The only addition during the cut was one session per week of 30 minutes of fast walking.

The real change was in the diet. Caloric intake dropped 44%, from roughly 5,620 calories per day in the bulking phase to 3,140 per day during the cut.

Carbohydrates took the biggest hit, cut by 62% from 820 g/day to 320 g/day. Protein was held steady throughout, landing at the upper end of current recommendations for athletes in a caloric deficit at 330 g/day (~2.7 g/kg).

Results: Body Composition

The athlete dropped 6.4 kg total, from 128.7 kg down to 122.3 kg. Fat-free mass fell by 4.72%, while the sum of the three skinfolds decreased by only 0.7 mm. Body fat went from 6.1% to 5.9% — a change of just 0.7 kg of actual fat.

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New research out of James Cook University compared three versions of the barbell back squat: free weights, chains, and elastic bands, and found that the type of resistance you use changes what happens at the hip and spine far more than it changes what happens at the knee. For coaches working with athletes managing lower back issues or those chasing power output, these findings offer a clearer picture of which tool to reach for and when. Let’s look a little closer.

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Aim

Researchers wanted to know how chains (CVR) and elastic bands (EVR) change the forces and movement patterns at each joint during the squat compared to a standard free-weight load. Most prior research had only looked at barbell speed and ground reaction force, and nearly all of it focused on bands only. This study went deeper, examining what happens at the ankle, knee, hip, lumbar spine, and lumbopelvis throughout both the lowering and lifting phases.

Methods

Fifteen trained men with an average squat 1RM of 124 kg completed five sessions over four weeks. After a 1RM test and a familiarisation session, they each performed one testing session per resistance condition in a randomised order. Every session used 80% of 1RM as the total load. For the variable resistance conditions, 20% of that load came from the chains or bands, with the remaining 60% on the bar. Subjects squatted to 115 degrees of knee flexion, and motion capture, along with force plates, collected detailed joint-level data. Kinetic and kinematic data were pulled from the second rep of each set.

Results

Repetitions completed varied considerably. Subjects averaged about 10 reps with free weights, 13 with chains, and 17 with bands. The lower effective load at the bottom of the squat allowed more reps across both variable resistance conditions.

Ground reaction force was highest with free weights. Both bands and chains produced lower peak ground reaction force, which reflects the reduced load at the bottom of the squat in both variable resistance conditions.

Rate of force development during the mid-concentric phase was significantly higher with chains than with free weights. Bands did not differ from free weights on this measure, which was an unexpected finding given that bands are often assumed to offer a power advantage through their elastic recoil effect.

Angular velocity was faster across the ankle, knee, and hip during both the lowering and lifting phases with bands and chains compared to free weights. Both variable resistance conditions moved similarly to each other in terms of speed.

Joint range of motion was the same across all three conditions at every joint. The type of resistance did not change how deep or how far subjects moved.

Joint moments at the ankle and knee were similar across all three conditions. Despite the load differences, the increased speed of movement with variable resistance compensated, producing comparable demand on the quads and calves.

Hip, lumbopelvis, and lumbar spine moments told a different story. Free weights produced significantly greater demand at these joints than both bands and chains during both the lowering and lifting phases. When comparing the two variable resistance types, chains produced greater hip, lumbopelvis, and lumbar spine moments than bands.

Joint power at the knee was greater with both bands and chains compared to free weights. At the hip, only chains produced greater power than free weights. Bands did not significantly increase hip power over free weights.

Practical Takeaways

The most actionable finding here is the split between what happens at the knee versus what happens further up the chain. Both bands and chains maintain similar knee-level stimulus to free weights, while reducing the load on the lower back. For athletes managing spinal injury or those with a history of lower back issues, bands in particular offer a way to keep training the legs hard without adding spinal stress.

For power development, chains appear to be the stronger option. The linear increase in load during the concentric phase with chains produced a greater rate of force development and greater hip power; bands did not match these advantages. The researchers suggest a logical progression for lifters: start with bands, move to chains, then progress to free weights, since each step increases demand further up the kinetic chain.

The study did not find clear evidence that either type of variable resistance augmented the stretch-shortening cycle at the point of the eccentric-to-concentric transition. The faster eccentric velocities with variable resistance may still carry SSC benefits, but the data could not confirm this definitively.

The main limitation is that only men were tested, and women are known to use different movement strategies during the squat, so these findings may not apply universally.

Reference

Alves, Adon V; Leicht, Anthony S; Deakin, Glen B; Doma, Kenji; Singh, Utkarsh; Brice, Sara M. Joint-Level Analysis of the Barbell Back Squat During Chain and Elastic Variable Resistance Use. Journal of Strength and Conditioning Research 40(5):p 511-518, May 2026. | DOI: 10.1519/JSC.0000000000005353

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

Researchers from the University of Milan used high-density surface electromyography (HD-sEMG) to map exactly where and how hard key back muscles fire during two seated row variations: narrow-grip and wide-grip. Fourteen resistance-trained men performed at their 8-rep max loads.

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Aim

To compare muscle excitation between the narrow grip seated row (narrow-SR) and wide grip seated row (wide-SR) using HD-sEMG, which goes beyond standard EMG by mapping the spatial distribution of muscle activity across a grid of electrodes.

Unlike standard single-electrode EMG, HD-sEMG can show not just how much a muscle fires, but where within that muscle the activity is concentrated. This was the first study to apply this technology to the seated row.

Methods

Fourteen resistance-trained men (average age ~25 years, body mass ~76 kg) with at least three years of training experience completed three sessions.

• Session 1: Familiarisation with both grip variations and electrode placement

• Session 2: 8-RM testing for both variations (order randomised)

• Session 3: Maximum voluntary isometric contractions recorded, then four reps of each exercise at 8-RM load, with both concentric and eccentric phases paced at 2 seconds using a metronome

Muscles monitored included: upper, middle, and lower trapezius; latissimus dorsi; lateral and posterior deltoid; biceps brachii; triceps brachii; and erector spinae.

The narrow-SR used a triangle attachment (elbows in, pulling toward the belly). The wide-SR used a straight bar (elbows flared, pulling to the lower chest). Both were performed on a Technogym cable machine.

Figure 1. Narrow grip and wide grip seated row technique.

Results

The narrow-SR consistently produced greater latissimus dorsi activation across both the concentric and eccentric phases. The wide-SR, despite using about 9 kg less, produced greater activation of the upper, middle, and lower trapezius, as well as the lateral deltoid, in both phases. During the eccentric phase only, the wide-SR also produced greater erector spinae activation. The posterior deltoid, biceps brachii, and triceps brachii showed no meaningful difference between grips.

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A new study out of Mississippi State University tracked 17 recreationally trained young men over nine weeks of resistance training and found that lifting heavy or light produced nearly identical muscle growth. The only edge heavy training had was strength gains. Hormones? Barely moved either way.

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Aim

Researchers wanted to know whether training load changes how much muscle you build and how your hormones respond. Specifically, they compared lifting at 85% of your one-rep max (1RM) against lifting at just 30% 1RM, both taken to failure, over nine weeks of full-body training.

Methods

Seventeen recreationally trained males with an average age of 20 years were split into two groups: a high-load group (85% 1RM, n = 8) and a low-load group (30% 1RM, n = 9). Both groups trained three days per week for nine weeks, performing three working sets per exercise to failure. The program included back squat, deadlift, bench press, T-row, bicep curls, and skullcrushers.

Muscle thickness was measured via ultrasound at the biceps, triceps, chest, hamstrings, and quads at baseline and every three weeks. Salivary testosterone and cortisol were collected first thing in the morning and immediately after training sessions. Predicted 1RM was tested at the start and end of the program.

Results

Both groups got bigger. Muscle thickness increased significantly over time across nearly every site measured, with no meaningful difference between groups. The one exception was the triceps, where the high-load group showed earlier and more consistent growth, with significant increases from week three onward compared to no clear change in the low-load group.

For strength, the high-load group came out ahead. Relative strength improvements in the squat, deadlift, and bicep curl were significantly greater in the heavy group, even after accounting for baseline differences.

On the hormone side, neither testosterone nor cortisol changed in a statistically meaningful way over the nine weeks, either at rest or in response to training sessions. Both groups showed a modest drop in testosterone immediately after exercise, though this did not reach significance. The authors noted this pattern could reflect androgen receptor uptake rather than a true decline, since the study measured free testosterone via saliva and resistance training is known to increase receptor activity.

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Key Takeaways

• Training to failure matters more than the weight on the bar when it comes to muscle growth

• Heavy loading (85% 1RM) produced greater relative strength gains in the squat, deadlift, and bicep curl

• The triceps showed a notable advantage for the heavy group, growing faster and more consistently

• Cortisol and testosterone stayed stable across both groups, suggesting both training approaches were similarly manageable from a recovery standpoint

• The drop in post-exercise testosterone seen in both groups may reflect androgen receptor binding rather than a hormonal problem

• Results apply to recreationally trained males only; women and elite athletes may respond differently

The study was small, which limits how confidently you can apply the findings. A larger sample and longer monitoring window, particularly for hormonal tracking, would strengthen the conclusions. Still, this adds to a growing body of evidence that for building muscle, effort and consistency are the key variables, not whether you are grinding heavy singles or doing high-rep sets.

Reference

Bello, M.L.; Arent, S.M.; Gillen, Z.M.; Smith, J.W. Muscle Hypertrophy, Strength, and Salivary Hormone Changes Following 9 Weeks of High- or Low-Load Resistance Training. J. Funct. Morphol. Kinesiol. 2026, 11, 17. https://doi.org/10.3390/jfmk11010017

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

Researchers tested whether overloading the lowering phase of bench presses with maximal or supramaximal weights improves the lifting phase power, force, and speed. They used weight releasers on 18 trained men doing reps at 40-80% of their one-rep max. They found the type of eccentric load made little difference to concentric performance. Load size mattered more, with lighter loads speeding up the bar and heavier ones building force. This shows that accentuated eccentric loading may not always enhance bench press output, especially for lifters with moderate strength.

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Aim

The study aimed to check the acute effects of maximal (100% of concentric one-rep max) and supramaximal (110%) accentuated eccentric loading versus traditional loading on bench press power, force, velocity, and eccentric duration. They wanted to see if weight releasers during the eccentric phase boost concentric metrics across loads from 40 to 80% one-rep max in trained men with a relative strength of 1.27 kg per kg body mass.

Methods

Eighteen men aged 24, 180 cm tall, 96 kg, with 2+ years training and bench one-rep max around 121 kg took part. After one-rep max testing and weight releaser familiarisation, they did three sessions: traditional loading, AEL100, and AEL110, in random order with 7-96 hours rest between. Each session had three reps per concentric load (40, 50, 60, 70, 80% one-rep max), three minutes rest between sets. A linear position transducer measured mean and peak power, velocity, force, and eccentric repetition duration. Stats used repeated measures ANOVA with post-hoc tests and Cohen’s d effect sizes.

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Researchers tested muscle excitation in the prone barbell row using three ranges of motion: full, upper half, and lower half. They found small to medium differences only in latissimus dorsi and trapezius transversus, with inconsistent patterns across measures. This matters because it shows range tweaks with fixed time under tension change back muscle activation a little, giving lifters simple options for upper back work

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Aim

The study measured surface electromyography (sEMG) in trapezius transversus, rear deltoid, latissimus dorsi, and biceps brachii during prone barbell rows at 10RM loads. Researchers compared mean and peak excitation across full ROM, upper-half ROM, and lower-half ROM. They standardised time under tension at 2 seconds concentric and 2 seconds eccentric to focus on range effects.

Methods

Sixteen trained men, average age 28, weight 81 kg, with 9 years lifting experience, did two sessions a week apart. First session set 10RM for each ROM using a machine like a Smith setup on a prone bench, grip 1.4 times shoulder width. Second session recorded sEMG during 10 reps per ROM after maximum voluntary isometric contractions for normalisation. Custom stops defined partial ROMs; data filtered and analysed with ANOVA.

Results

Lower-half ROM used the heaviest load at 70 kg, full at 49 kg, and upper-half at 44 kg. Latissimus dorsi mean excitation is highest in the upper-half ROM. Trapezius transversus peak excitation is lowest in the upper-half ROM. The rear deltoid and biceps showed no differences.

Key Takeaways

When time under tension is controlled, changing the range of motion in the prone barbell row produces only small to moderate differences in back muscle activation, and those differences are inconsistent across measures.

For most lifters, this means ROM selection in the prone row is less critical than the broader training variables most coaches already prioritise, such as load, volume, and proximity to failure.

A few specific patterns are worth noting:

• Latissimus dorsi showed higher mean activation in the upper-half ROM compared to the full and lower-half ROM. If lat development is the priority, the upper portion of the row may offer a marginal edge.

• Trapezius transversus showed lower peak activation in the upper-half ROM compared to both the full and lower-half. Lifters targeting upper back thickness may want to avoid restricting the row to the top half.

• Lower-half ROM required the heaviest absolute load at 10RM intensity. For strength-focused blocks, this range allows more weight on the bar at matched relative effort.

• Rear deltoid and biceps brachii showed no meaningful differences across any range. ROM selection will not change how hard those muscles work.

The researchers stress these results should be treated as reference data. EMG does not directly predict hypertrophy or long-term strength gains, so decisions about ROM should also account for joint comfort, training history, and the specific muscles a lifter is prioritising in a given training block

Reference

Fischer, J., Burger, C., Seguel, J. M., Rodoplu, C., Paternoster, F. K., Tilp, M., & Konrad, A. (2025). Impact of different ranges of motion in the prone barbell row on muscle excitation. Journal of Electromyography and Kinesiology, 83, 103025. https://doi.org/10.1016/j.jelekin.2025.103025

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.

A recent study published in Scientific Reports examined how the leg and back muscles synchronise and integrate as a network during a squat test performed to exhaustion. Women showed stronger, more stable inter-muscular coordination throughout the test. Men showed weaker but more adaptable inter-muscular coordination and lasted longer on average, though the performance gap was not statistically significant. The findings suggest that how muscles coordinate at a network level may help explain sex-based differences in fatigue, injury risk, and training response.

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Aim

Researchers wanted to understand how the leg and back muscles synchronise and integrate as an inter-muscular network during a squat test performed to exhaustion, and whether that coordination differs between men and women. A secondary aim was to examine how the temporal variability of those inter-muscular interactions changes over the course of the test, something that had not been studied before in this context.

Methods

38 healthy young adults participated: 11 males (average age 21.9 years) and 27 females (average age 22.5 years). All were sport science students who exercised regularly but were not competitive athletes.

Participants performed a bodyweight back squat to exhaustion at a controlled 3-seconds-down, 3-seconds-up tempo, regulated by a metronome. Exhaustion was defined as the inability to maintain that tempo for three consecutive repetitions.

Surface electromyography (sEMG) sensors were placed on four muscles: the left and right vastus lateralis and the left and right erector spinae. Researchers used a novel analytical method called Amplitude-Amplitude Cross-Frequency Coupling (ACFC) to measure how the inter-muscular coordination between different frequency bands in these muscles changed throughout the test.

Results

Men lasted an average of 673 seconds; women averaged 465 seconds. This difference was not statistically significant.

Despite performing for less time, women showed stronger average inter-muscular coordination across nearly all muscle pairings. In the cross-body muscle pairs, such as the right leg with the left back, women showed 20 to 30% stronger inter-muscular coordination.

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A new study out of Turkey shows that training during Ramadan fasting can dramatically influence which muscles grow stronger and how your body composition changes. Over four weeks, 32 male university students who fasted daily from pre-dawn to sunset completed high-intensity functional workouts either two hours before or two hours after breaking their fast, with both groups experiencing significant gains but in distinctly different areas of the body. The pre-meal group showed greater strength improvements in upper body and postural muscles, while the post-meal group gained more in lower body strength and saw more drastic positive changes in body composition. Only one muscle group, the gluteus maximus, showed a statistically significant difference between the two groups, with the post-meal trainees achieving substantially greater strength gains in this large hip muscle.

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Aim

To examine how functional training performed during Ramadan affects body composition, muscle strength, and muscle growth, depending on whether the workout happens before or after the evening meal that breaks the daily fast. The study specifically investigated whether the timing of training in relation to nutritional status could determine the direction and magnitude of physical adaptations during the month-long fasting period.

Methods

Study Design and Participants

The study enrolled 32 sedentary male university students from Karabük University who maintained daytime fasting throughout Ramadan, abstaining from all food and drink from pre-dawn (around 12 to 20 hours daily depending on geographic location) until sunset. Participants were randomly assigned to either a pre-iftar group (training 2 hours before breaking the fast) or a post-iftar group (training 2 hours after the evening meal), with 16 men in each group. The pre-iftar group averaged 21.94 years old with a body weight of 81.92 kg and 19.39% body fat, while the post-iftar group averaged 23.50 years old, weighed 82.18 kg, and had 19.10% body fat, showing comparable baseline characteristics.

Training Program

The high-intensity functional training program ran for four weeks with three sessions per week at a fitness centre in Karabük. Each session lasted 12 minutes of actual high-intensity functional training, with total session duration ranging from 35 to 50 minutes, including warm-up and cool-down. The program consisted of eight exercises performed for three sets each, with a work-to-rest ratio of 30 seconds work to 15 seconds rest, or 20 seconds work to 10 seconds rest, at 80% of maximum heart rate.

The eight exercises included squat or lunge, lat pull-down, sprinting in place, push-up, box step-ups, sidewalk plank, deadlift, and medicine ball toss. This combination targeted multiple muscle groups across the entire body through compound movements and high-speed exercises typical of high-intensity circuits or functional training approaches.

Measurements

Researchers assessed participants at two time points: before the training program began during the first week of Ramadan, and after the four-week program ended during the final week. Both assessments occurred in the morning between 9:00 and 10:00 AM, immediately after the pre-dawn meal, to ensure consistent measurement conditions

Body composition analysis used bioelectrical impedance to measure body weight, body mass index, body fat percentage, muscle mass, and fat-free mass index. Circumference measurements captured chest, shoulder, hip, biceps, thigh, and waist measurements using a non-stretchable cloth tape.

Muscle strength testing employed hand-held dynamometry fixed with an external belt to measure isometric strength in numerous muscle groups, including hand grip strength for both hands, leg and back strength using specialised dynamometers, and targeted assessments of hamstrings, quadriceps, gluteus maximus, gluteus medius, latissimus dorsi, triceps, shoulder rotation muscles, and lower trapezius for both sides of the body. After each strength test, participants rated their perceived exertion using the Borg 6-20 scale.

Results

Between-Group Comparisons

Before training began, the two groups showed no significant differences in baseline body composition or most strength measures, though the pre-iftar group demonstrated higher left triceps strength (21.88 kg vs 18.46 kg), higher left shoulder external rotation strength (19.82 kg vs 16.33 kg), and lower isometric perceived exertion scores (10.81 vs 13.00) compared to the post-iftar group.

After four weeks of training, the only statistically significant differences between groups appeared in the gluteus maximus muscles. The post-iftar group achieved dramatically greater strength gains, reaching 38.23 kg in the right gluteus maximus compared to 30.65 kg in the pre-iftar group, and 40.17 kg in the left gluteus maximus versus 29.13 kg in the pre-iftar group.

Pre-Iftar Group Changes

Within the pre-iftar group, participants experienced significant improvements across multiple parameters. Muscle mass increased from 59.42 kg to 60.35 kg, while body fat percentage decreased from 19.39% to 18.37%. Hand grip strength improved in both hands, with right-hand grip rising from 45.65 kg to 48.08 kg and left-hand grip from 45.43 kg to 46.62 kg. Back strength jumped from 143.43 kg to 153.12 kg, and leg strength increased from 167.81 kg to 178.75 kg.

Upper body circumferences showed notable increases, with shoulder circumference expanding from 119.87 cm to 124.62 cm, chest circumference from 104.18 cm to 106.31 cm, right biceps from 36.75 cm to 37.50 cm, and left biceps from 36.12 cm to 37.43 cm. Lower body strength in specific muscles also improved, with right hamstring strength rising from 31.43 kg to 34.26 kg and left hamstring from 32.80 kg to 36.95 kg. The gluteus maximus showed substantial gains, with right side strength increasing from 24.76 kg to 30.65 kg and left side from 21.76 kg to 29.13 kg. Right gluteus medius strength also improved from 21.70 kg to 24.60 kg.​

Interestingly, left quadriceps strength decreased from 33.78 kg to 29.88 kg, as did left shoulder internal rotation strength (20.66 kg to 18.16 kg) and left shoulder external rotation (19.82 kg to 18.30 kg). Perceived exertion scores increased across several tests, suggesting participants found the exercises more challenging as the program progressed.

Post-Iftar Group Changes

The post-iftar group experienced even more pronounced changes in several areas. Muscle mass increased from 60.15 kg to 60.84 kg, while body fat percentage dropped from 19.10% to 17.59%, and BMI decreased from 26.40 to 26.15 kg/m². Right-hand grip strength improved from 46.56 kg to 49.11 kg, and leg strength surged from 161.87 kg to 173.43 kg.

Body circumferences showed selective increases, with shoulder circumference expanding from 122.00 cm to 125.06 cm, right biceps from 35.25 cm to 35.81 cm, and left biceps from 34.75 cm to 35.68 cm. Notably, waist circumference decreased from 90.56 cm to 88.75 cm, indicating fat loss in the abdominal region.

Lower body strength showed remarkable improvements, particularly in the glutes. Left hamstring strength increased from 32.69 kg to 39.21 kg, while right gluteus maximus strength skyrocketed from 24.65 kg to 38.23 kg and left gluteus maximus from 23.74 kg to 40.17 kg. Both gluteus medius muscles also strengthened significantly, with the right increasing from 21.31 kg to 26.55 kg and the left from 22.36 kg to 26.95 kg. Right triceps strength improved from 19.18 kg to 21.18 kg.

Similar to the pre-iftar group, quadriceps strength decreased in both legs, with right quadriceps dropping from 33.28 kg to 29.07 kg and left quadriceps from 34.66 kg to 27.53 kg. Leg strength perceived exertion scores decreased from 13.87 to 12.37, suggesting participants found this exercise easier over time despite lifting heavier loads.

Key Takeaways

Training timing during fasting periods matters for specific goals. If you’re fasting and want to prioritise upper body and postural muscle development, training before eating appears effective, though you’ll be working in a depleted state. However, if your focus is building lower body strength, particularly in the glutes and hamstrings, or improving overall body composition by reducing fat while maintaining or building muscle, training after a meal provides superior results.

Glute development responds dramatically to post-meal training. The most striking finding was the massive strength gains in the gluteus maximus for the post-meal training group, with increases exceeding 50% in just four weeks. This large muscle group appears particularly responsive to training when adequate nutrition and hydration are available, likely due to enhanced muscle protein synthesis and recovery capacity after eating.

Both approaches build muscle and reduce fat during fasting. Regardless of timing, all participants increased muscle mass and decreased body fat percentage over the four-week program while fasting daily. This demonstrates that high-intensity functional training can produce positive body composition changes even under the metabolic stress of prolonged daily fasting.

The quadriceps puzzle warrants attention. Both groups experienced decreases in quadriceps strength despite increases in overall leg strength and other lower-body muscles. This unexpected finding might relate to the specific exercises used, muscle fatigue accumulation, or measurement variability, and suggests that targeting the quads specifically during fasting periods may require additional exercise selection or training volume.

Practical application depends on your fasting schedule. For those observing Ramadan or similar fasting practices, these findings support scheduling high-intensity functional training around meal timing based on your priorities. The study used a specific protocol of training either 2 hours before or 2 hours after the evening meal, three times per week, with 12-minute high-intensity sessions built around compound movements like squats, deadlifts, push-ups, and medicine ball tosses. Arguably, the latter exercise could surely be left out if the goal is muscle retention or growth, seeing as it contributes nothing to either and instead may only increase workout fatigue. This time-efficient approach, performed at 80% of maximum heart rate with short rest periods, proved effective for driving adaptations in both fasted and fed states.

Reference

Uzun ME, Şahin M, Bezci Ş, et al. Investigation of the Effects of Ramadan Fasting and High-Intensity Functional Training on Body Composition, Isometric Strength, and Hypertrophy. Turk J Sport Exe. December 2025;27(3):542-554. doi:10.15314/tsed.1802280

You can also find me at dannyleejames.com for stories, personal training insights, and coaching.