Resistance training is an important part of staying strong. The general rule for achieving the maximum benefit is to work the muscle until fatigue, that is to repeat the movement until you are unable to complete another full movement. The idea is to then increase the number of repetitions as the body becomes stronger. In this way, the muscle is always being challenged.
Of course, refuelling with a high leucine whey protein isolate is recommended to assist in muscle recovery and ensure you get the full benefit of the workout while preventing muscle soreness.
But while there seems to be consensus on the number of repetitions, there are few studies on the ideal number of sets of repetitions in older women. A recent study has shown surprising results.
In this small study(1), 26 older women undertook 12 weeks of muscle training. They were split into two groups: one group would perform one set, the other three sets. After 12 weeks, muscle quality and functionality was measured. Both groups showed significant, but surprisingly similar, improvements in muscle quality and function.
The paper's authors concluded that although muscle quality declines with advancing years, weight training is a feasible and effective way to mitigate this decline. But surprisingly, there was no evidence of a dose-response. In this group of older women, more sets did not result in improved muscle quality; a single set was just as effective as three sets.
It seems to key to staying strong is to stay active - hit the gym, work hard but don't overdo it. Once you've worked the muscle there's no benefit in continuing for more sets. It is, however, important to stretch. More on that later...
Radaelli, R et al (2019) Muscle quality and functionality in older women improve similarly with muscle power training using one or three sets Experimental Gerontology Volume 128, December 2019, 110745 from https://www.sciencedirect.com/science/article/pii/S0531556519305844?via%3Dihub retrieved 1/11/2019.