New ACSM Position Stand: Resistance Training for Muscle Strength, Hypertrophy, and Performance.
The largest resistance training review ever published identifies exactly which training variables drive results, and which ones you can stop arguing about.
The American College of Sports Medicine has released its most comprehensive resistance training Position Stand, and the findings are very cool if you want an evidence-based round-up of what we know and what works in strength.
In a nutshell: To build strength, lift heavy loads at 80% of your one-rep max (1RM) or above, train at least twice a week, use a full range of motion, and do 2 to 3 sets per exercise. To build muscle, accumulate at least 10 sets per muscle group per week and incorporate eccentric overload. To develop power, use moderate loads between 30% and 70% 1RM, keep volume low to moderate, and train explosively. As for training to failure, periodisation, free weights versus machines, time under tension, and blood flow restriction? The evidence says none of them makes a meaningful difference consistently.
Published in Medicine & Science in Sports & Exercise in 2026, the Position Stand is led by Brad Currier and Stuart Phillips at McMaster University, alongside a 13-person author team spanning institutions across North America and Australia. It synthesises 137 systematic reviews covering more than 30,000 people, and formally updates the ACSM's 2009 Position Stand on resistance training prescription, which was previously criticised for lacking methodological rigour.
Aim
The purpose of this overview of reviews was to determine which resistance training prescription variables, the specific details of how a program is designed, actually drive improvements in muscle strength, hypertrophy, power, endurance, and physical function, such as gait speed, balance, and chair-stand performance in healthy adults.
A secondary aim was to distinguish between two different questions: does resistance training work compared to doing nothing, and within resistance training, which specific variables produce superior outcomes when compared head-to-head. Those are two very different questions, and the paper addresses both.
Methods
The researchers conducted what is known as an umbrella review, a systematic review of existing systematic reviews and meta-analyses. Trained librarians searched six major databases, including Ovid MEDLINE, Embase, Cochrane, and SPORTDiscus, with searches current to October 2024.
To be included, a review had to cover randomised trials of healthy adults (18 years or older) who completed at least six weeks of resistance training, compared against either a no-exercise control group or a distinctly different training program. Four independent reviewers screened 5,751 records after duplicate removal, ultimately including 137 systematic reviews. Quality of individual reviews was assessed using the AMSTAR tool (scored out of 11), and quality of evidence was graded using a GRADE-based approach, expressed as a percentage score from 0% to 100%
The prescription variables examined were extensive, covering training frequency, load (%1RM), sets and volume, training to failure, time under tension, rest periods, exercise order, range of motion, contraction type (eccentric vs. concentric), set structures such as drop sets and cluster sets, blood flow restriction, periodisation, and more.
Results
Resistance training versus no exercise at all. Compared to doing nothing, resistance training significantly improved strength (26 reviews, n = 23,204; quality of evidence 73%), hypertrophy (12 reviews, n = 14,924; quality of evidence 79%), power (4 reviews, n = 1,001; quality of evidence 63%), muscular endurance, gait speed, balance, chair stand performance, and timed up-and-go scores. This held across multiple training modalities, including standard free-weight and machine training, elastic band training, circuit training, home-based training, and velocity-based training.
For strength, the variables that matter:
Load at 80% 1RM or above, with a clear dose-response relationship (6 reviews, n = 6,574; quality of evidence 79%)
Frequency of at least 2 sessions per week (4 reviews, n = 3,531; quality of evidence 69%)
Full range of motion versus partial range (2 reviews, n = 1,262; quality of evidence 50%)
2 to 3 sets per exercise, with more sets clearly beating fewer (7 reviews, n = 5,633; quality of evidence 71%)
Performing priority exercises at the start of a session rather than the end (4 reviews, n = 941; quality of evidence 88%)
For hypertrophy, the variables that matter:
Volume of at least 10 sets per muscle group per week, with a dose-response relationship up to approximately 18 to 20 sets per week (5 reviews, n = 2,267; quality of evidence 50%)
Eccentric-only contractions versus concentric-only contractions (1 review, n = 868; quality of evidence 75%)
Load was not a significant factor for hypertrophy. From 30% 1RM to 100% 1RM, muscle growth outcomes were comparable when effort was sufficient
For power, the variables that matter:
