Higher-load resistance training produces greater improvements in dynamic 1-RM strength in individuals under 60 years of age compared to individuals aged 60 years and older, with effect sizes of 0.41 and 0.20, respectively.

When lifting heavy weights, the nervous system must activate more muscle fibers at higher speeds to produce maximum force. Younger people can do this more effectively because their nerves send stronger and faster signals to muscles, and they can better turn off opposing muscles to allow full force output. Older adults have weaker nerve signals, slower firing rates, and less ability to suppress opposing muscles, so even when lifting heavy weights, they cannot recruit as many muscle fibers or generate the same peak force, limiting their strength gains.