Why some older men get much stronger than others from lifting weights
Heavy resistance exercise training in older men: A responder and inter-individual variability analysis
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Only 5% of participants were true 'poor responders'—far fewer than the 15–20% often assumed in exercise science.
Most fitness content suggests 1 in 5 people don’t respond to training. This study, using gold-standard methods and a control group, shows true non-response is extremely rare in healthy older men.
Practical Takeaways
If you're over 65 and haven’t lifted weights, start with 3x/week heavy resistance training—don’t wait to feel 'ready'.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Only 5% of participants were true 'poor responders'—far fewer than the 15–20% often assumed in exercise science.
Most fitness content suggests 1 in 5 people don’t respond to training. This study, using gold-standard methods and a control group, shows true non-response is extremely rare in healthy older men.
Practical Takeaways
If you're over 65 and haven’t lifted weights, start with 3x/week heavy resistance training—don’t wait to feel 'ready'.
Publication
Journal
PLOS One
Year
2025
Authors
Casper Soendenbroe, J. L. Andersen, M. F. Heisterberg, Michael Kjaer, A. Mackey
Related Content
Claims (6)
When people who’ve never lifted weights before start training, some gain just a little muscle—like half a kilo—while others gain a lot, up to three kilos, in about two to three months.
Older men who start out weaker or with smaller fast-twitch muscle fibers tend to get bigger gains from heavy weight training, but even knowing how weak they were at the start doesn’t fully explain why some people improve more than others.
When older men do heavy weight training, some get much stronger and build more muscle than others—even when they do the same workout—and those differences are bigger than any mistakes we might make when measuring them.
When older men who are healthy lift heavy weights for 16 weeks, most of them—82%—get much stronger and build more muscle, while barely 5% don’t improve much, so it’s rare for someone to not benefit at all.
If older men in their early 70s lift heavy weights three times a week for four months, they’ll get noticeably stronger and their big muscle fibers will grow bigger.