Yes. In a meta-analysis of 49 studies covering 1,328 previously untrained adults aged 50 to 83, supervised resistance training for about 20 weeks raised lean body mass on average, and the pooled result was clearly above zero3.
Age changes how much and how fast, not whether. Gains tended to be smaller the older people were, and somewhat smaller than in young adults, but muscle grew even in people in their nineties1.
What was studied
The anchor is a 2011 meta-analysis, a study that pools the results of many earlier studies3. It included every study it could find, published from 1990 to 2009, in which adults aged 50 or older did supervised resistance training (working muscles against a load: weights, machines, bands). Participants had done no resistance training in the prior six months. Programmes designed to manage a specific disease were excluded3.
The outcome was lean body mass: everything in the body except fat, mostly muscle and water. It was measured with lab methods such as underwater weighing or DXA, a low-dose X-ray scan3.
| What | Number |
|---|---|
| Studies | 49 (81 training groups) |
| People | 1,328, aged 50 to 83 (mean about 65) |
| Training length | 10 to 52 weeks (mean about 20) |
| Sessions | 2 to 3 a week |
| Load | 50% to 80% of the one-rep max (mean about 75%) |
| Sets per session | 7 to 39, whole body |
In plain terms: a large body of evidence on ordinary older adults who started lifting, under supervision, for a few months.
What the studies found
Lean mass went up. Pooling all 81 training groups, lean body mass rose by an average of 1.1 kg (95% confidence interval 0.9 to 1.2 kg)3. A confidence interval is the range the true average most likely sits in; here the whole range is above zero. This is a group average across studies, not what any one person gained.
More sets, more gain. The authors ran a meta-regression, a test of whether study features line up with bigger or smaller results. Programmes with more work sets per session were linked with larger increases in lean mass3.
Older, less gain. In the same analysis, older age was linked with smaller increases3. The authors still note that significant hypertrophy is possible in the oldest old, and suggest that starting earlier may bring larger returns3.
Head to head with young adults. One trial put 25 adults aged 60 to 75, described by the authors as sarcopenic (low muscle mass for their age), and 24 aged 20 to 35 on the same programme, three days a week for 16 weeks2. Both groups grew their fast (type 2) muscle fibres, the ones that grow most with lifting. The older group's grew by 23% on average, the younger group's by 32%. Growth was generally most favourable in young men2.
Growth of fast (type 2) muscle fibres after 16 weeks of the same training · %
Even in the nineties. In 1990, ten frail nursing-home residents aged about 90 did eight weeks of high-intensity leg training; nine finished. Their strength rose by 174% on average, and the area of their mid-thigh muscle by 9.0%1.
In plain terms: muscle responds to training at every age studied. The response gets somewhat smaller with age, but it does not disappear.
Strength arrives before size
Strength rises faster than size in older adults, as in the young. In a small trial of older adults whose thighs were scanned every week, leg press strength rose 42% in ten weeks, while muscle size changed measurably only after 18 sessions, about nine weeks, by 7.1%4. The time course is covered in more detail in how long it takes to build muscle.
Individual responses vary widely at any age. In 287 untrained adults aged 19 to 78, muscle size change after training ranged from −11% to +30%, and neither age nor sex changed the average response5. That study and the 2006 trial measured differently, so they are not a contradiction: one compared age groups directly, the other looked at spread across a wide age range.
How much training did the studies use?
The 2011 meta-analysis found more volume linked with more lean mass3. A 2025 network meta-analysis of 151 randomised trials in adults aged 60 and over (6,306 people) reached a different conclusion about the minimum6. It split programmes into low, moderate and high weekly volume. Low-volume training was already effective for lean body mass and lower-body muscle size, while higher volumes were needed for the largest strength gains6.
Low-volume resistance training vs control, adults aged 60 and over · SMD
The two are compatible. More sets can mean more gain on average, while a modest programme still produces measurable change. The trials used supervised, progressive programmes, usually two to three sessions a week. For how sets are counted per muscle, see how many sets per muscle group per week; for a starting structure, see the beginner workout program.
What this does and does not mean
- It does not promise a number. The 1.1 kg is a pooled average across 81 groups with very different programmes. Individuals varied a lot.
- Lean body mass is not pure muscle. It includes water and organs, so it is a rough measure of muscle.
- Supervised programmes. Every study in the 2011 analysis was supervised. Unsupervised training was not tested.
- Healthy adults, mostly. The 2025 results were mainly in physically healthy older adults; evidence for people with impairments was limited6. For anyone with a health condition, a doctor is the right person for individual questions before starting.
- Energy use is a separate question. For what happens to daily calorie needs with age, see does metabolism slow down with age.
The studies at a glance
| Study | Who was studied | Key result | Year |
|---|---|---|---|
| Fiatarone et al., *JAMA*1 | 10 frail nursing-home residents aged about 90, 8 weeks | Strength up 174%; mid-thigh muscle area up 9.0% (9 finished) | 1990 |
| Kosek et al., *J Appl Physiol*2 | 25 adults aged 60–75 and 24 aged 20–35, 16 weeks | Fast-fibre size up 23% in older vs 32% in younger adults | 2006 |
| Peterson et al., *Med Sci Sports Exerc*3 | 49 studies, 1,328 adults aged 50–83 | Lean mass up a pooled 1.1 kg; more volume more gain; older age less | 2011 |
| Lixandrão et al., *J Strength Cond Res*4 | 14 older adults, 6 trained, scanned weekly | Strength up 42%; size up 7.1%, measurable after 9 weeks | 2016 |
| Ahtiainen et al., *Age*5 | 287 untrained adults aged 19–78 | Size change −11% to +30%; age and sex did not change the average | 2016 |
| Radaelli et al., *Sports Med*6 | 151 randomised trials, 6,306 adults aged 60+ | Low volume effective for lean mass and muscle size | 2025 |
Limits worth knowing
- Few randomised trials in the 2011 pool. Only 37% of the 49 studies had a randomised control group; the rest measured people before and after3.
- Association, not cause, in the regressions. The links with volume and age come from comparing studies, not from testing them head to head. The authors say the data do not infer a causal effect3.
- High spread between studies. Heterogeneity (how much studies disagree) was high: I² was 84%3.
- Small trials. The 1990 study had nine finishers; the weekly-scan study had six people training.
- Abstract only for five of six. We read the 2011 meta-analysis in full; the other numbers come from the abstracts.
Latest research
The newest study we opened is the 2025 network meta-analysis of 151 randomised trials in adults aged 60 and over6. Its searches ran to April 2023. Low-volume programmes improved lean body mass (standardised mean difference 0.25) and lower-body muscle size (0.40), independent of programme length. A standardised mean difference expresses an effect in units of spread, so it can pool studies that measured in different ways; 0.2 is conventionally small and 0.5 medium. Higher volumes were needed mainly for the largest strength gains. The authors' conclusion: a low volume can already change lean mass and muscle size in healthy older adults.
The short version
- Yes: across 49 studies, adults aged 50 to 83 gained lean mass with about 20 weeks of supervised training.
- Gains tend to be somewhat smaller with age, but muscle grew even in people around 90.
- More sets were linked with more gain, yet low-volume programmes still worked in the newest analysis.
- Strength rises first; size follows over weeks to months.
Educational overview only — not medical advice.
