Train Before or After Breaking Your Fast?
Research on 32 fasting athletes reveals when you eat relative to your workout determines which muscles grow stronger and how your body composition changes.
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.
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
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