One side says heavy. The other says light. Both came with research, both sounded sure, and neither one mentioned a third option that targets the one thing aging actually takes from you.
Are Low Reps or High Reps Better for Older Adults?
Muscle growth did not change with load anywhere from 30% to 100% of your max. Strength improves with a dose-response favoring loads of 80% and above. Power training, lifting as fast as you can on the way up, was the only variable that enhanced walking performance compared with standard training, and it also enhanced combined physical-function scores, in reviews of older adults.
— Currier et al. 2026 · Med Sci Sports Exerc · 137 reviews, n>30,000
For building muscle, the weight you pick barely matters. Whether you lift at 30% of your max or push to 100%, the growth is equivalent — provided the effort is real. Whether low reps or high reps are better for older adults dissolves completely for the first goal: both produce the same muscle.
Strength follows a different rule. The heavier the load — particularly from 80% of your max up — the more force your muscles produce. If what you care about is getting stronger, not just bigger, the evidence tilts toward the heavy end. That feels like the answer you came for.
Except there was a third column the debate never included. **Power training, lifting as fast as you can on the way up, was the only training variable that enhanced walking performance compared with standard training, and it also enhanced scores that combine several tests of the physical function aging quietly erodes.** Not heavier weights. Not lighter weights. A speed of contraction that almost nobody programs for, targeting the outcomes that matter most after 60 and that neither side of the heavy-versus-light argument ever mentioned. The reviews behind it studied older adults.
How solid is the evidence? The American College of Sports Medicine’s 2026 position stand drew on 137 systematic reviews and more than 30,000 participants — their first resistance training update in 17 years. Its reviews were not split by age; the authors say their recommendations apply across all ages. The power evidence rests on fewer reviews than the strength or hypertrophy evidence, and most of the underlying research involves people who were new to training. Both are real limitations. And power is not the only route to function: compared with doing nothing, standard resistance training improved gait speed, balance and the ability to rise from a chair. Whether power training beats standard training on those three, the reviews could not yet say.
Training to failure proved unnecessary for any of the three goals — and for older adults, potentially risky. The position stand proposes stopping near failure, or aiming for about two to three reps short, while noting there is not yet enough evidence to set an exact target. In an analysis of more than 38,000 participants it cites, over 11,000 of them older adults, exercise did not increase serious adverse events.
Three goals. Three loading ranges. The framework exists now. What it leaves open is how all three fit inside a single training week — which sessions go heavy for strength, which go fast for power, and whether the volume that builds muscle after 60 follows the same rules as the volume that builds it at 25.