Muscle strength
kg (1RM or FFM)
How much force a muscle can produce, or the lean mass that usually travels with it. It is an outcome, not the habit of going to the gym.
Trials report a one-rep max, a predicted 1RM from reps to fatigue, handgrip strength, or lean and fat-free mass. Resistance training is work that may change those numbers. A memory-task score is a different outcome, and water alone can move a lean-mass reading without a stronger contraction.
Also called lean mass, fat-free mass, 1RM, muscular strength.
Connected relationships
Randomized trial · Contested
Creatine supplementation→Muscle strength
Higher Creatine supplementation moves Muscle strength only in some conditions. Read the mechanism.
Assigned creatine raised predicted one-rep strength more than lifting alone in 45 older adults (Amiri 2023) and raised fat-free mass in a five-day load (Mihic 2000), but a two-year postmenopausal trial found no extra one-rep max (Chilibeck 2023).
Randomized trial · Moderate
GLP-1 receptor agonist→Muscle strength
Higher GLP-1 receptor agonist decreases Muscle strength.
In 160 adults with obesity who sat for a DXA scan in SURMOUNT-1, weekly tirzepatide cut lean mass by 10.9 percent versus 2.6 percent on placebo (Look 2025). About a quarter of the lost weight was lean on both arms. Fat mass fell more.
Sources
- E Amiri et al. (2023). The role of resistance training and creatine supplementation on oxidative stress, antioxidant defense, muscle strength, and quality of life in older adults.
- S Mihic et al. (2000). Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women.
- PD Chilibeck et al. (2023). A 2-yr Randomized Controlled Trial on Creatine Supplementation during Exercise for Postmenopausal Bone Health.
- ACB Marini et al. (2024). Effect of Creatine Supplementation on Body Composition and Malnutrition-Inflammation Score in Hemodialysis Patients: An Exploratory 1-Year, Balanced, Double-Blind Design.
- M Look et al. (2025). Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight.
- RJ McCrimmon et al. (2021). Effects of once-weekly semaglutide vs once-daily canagliflozin on body composition in type 2 diabetes: a substudy of the SUSTAIN 8 randomised controlled clinical trial.