Strength Training: Overview
Essentially any structured, progressive resistance-training programme increases strength and muscle mass in healthy adults; the variables that follow tune the result rather than decide whether there is one.
Individual response varies; those with medical conditions should consult a professional before intensive training.
- Persistent pain or symptoms that do not resolve with rest
- Exertional chest pain, dizziness or breathlessness
What the evidence says
The sources are meta-analyses of resistance-training prescriptions in healthy adults and older adults. Currier 2023 (meta-analysis) reports that any resistance-training program is beneficial for muscle strength and hypertrophy, and concludes that all prescriptions can raise muscle strength and mass in healthy adults; Lyristakis 2024 (meta-analysis) reports large pooled improvements in strength (SMD at least 1.3) and concludes that volume and duration should be prioritised for developing strength; Borde 2015 (meta-analysis) reports improved strength in healthy older adults (mean SMD 1.57); Edouard 2023 (meta-analysis) concludes that as soon as individuals start training at a certain minimum dosage regularly, it is effective at improving muscle structure and function. The variables on the entries that follow (volume, load, frequency, effort, periodization) are what the sources compared once a program exists.
- (myth: You need to train like a bodybuilder to benefit.) CORRECTION: Any resistance-training program benefits strength and muscle, and a minimum regular dose reliably improves muscle structure and function.
- Does not diagnose, treat, or cure any disease or injury
- Not a substitute for individualized medical or physical-therapy advice
- Results vary between individuals; no guaranteed outcome
- Agreement
- consistent for this claim. Direction recorded for 3 of 4 sources; not yet recorded for the rest.
- The claim's outcome
- Outcome not yet recorded
- Certainty
- No source states a certainty rating.
What each source measured and concluded (4)
- What it measured
- Muscle strength and hypertrophy.
- How it measured it
- Muscle strength: 1RM test, isometric maximum voluntary contraction, isokinetic maximum voluntary contraction. Muscle hypertrophy: Ultrasonography, MRI, CT, bioelectrical impedance, dual-energy X-ray absorptiometry, hydrostatic weighing, air displacement plethysmography, microscopy.
- How it was read
- read in full text
- What the review says it includes
- systematic review and meta-analysis
- Studies and participants, as stated
- N = 8,461 participants across 192 studies
- What it measured
- Muscle strength (chest and quadriceps)
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What it measured
- Muscle strength (via 1RM and MVC) and muscle morphology (via MRI, CT, DEXA, ultrasound, or BOD POD).
- How it measured it
- Validated measures such as 1RM and MVC for strength; MRI, CT, DEXA, ultrasound, or BOD POD for muscle morphology.
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What the review says it includes
- meta-analysis, systematic review
- Studies and participants, as stated
- N = 819 participants across 25 studies
- Heterogeneity, as stated
- Considerable large heterogeneity (I2 = 80%)
- What it measured
- Muscle strength, hypertrophy, and physical function.
- How it measured it
- Systematic review and Bayesian network meta-analysis of existing studies.
- Direction it states for the claim's outcome
- Improved
- Its conclusion, in its own words
- “It is highly encouraging to see that as soon as individuals start training at a certain minimum dosage regularly, it is effective at improving muscle structure and function.”
- How it was read
- read in full text
Every source below is shown with its study design and links to the original study. This is the audit trail.