High-intensity resistance training to preserve muscle strength as we age

Skeletal muscle function and autonomy decline with age. Resistance exercises can partially counteract the loss of muscle mass and function. Indeed, studies indicate that short training periods (6–9 months) can partially preserve muscle mass and function after 6–12 months (see here and here). However, few studies have followed participants long-term. In one study, high-intensity resistance training, but not moderate-intensity resistance training, maintained gains in muscle strength after 48 weeks of detraining. Another study, the Live Active Successful Ageing (LISA) study, showed that muscle strength could be maintained for up to 1 year after a year of high-intensity resistance training, but not after moderate-intensity training. It therefore appears that high intensity or heavy loads are necessary to achieve long-term results.

In a recent study of the LISA cohort, adult participants of retirement age were divided into three groups who were assigned to: 1) high-intensity resistance training for 1 year; 2) moderate-intensity resistance training for 1 year; and 3) no training (control group). The primary outcome measure was a measure of leg extensor muscle power. Participants were assessed at baseline and 1 year, 2 years, and 4 years later.

Figure 1. Isometric leg muscle strength in the three groups of participants over a 4‑year period. Adapted from Bloch-Ibenfeldt et al., 2024.

The main results of the study are illustrated in Figure 1. Muscle strength increased significantly after 1 year of high-intensity resistance training (Group 1), and this muscle strength was preserved 4 years later, compared with the baseline. In Group 2, which did 1 year of moderate-intensity resistance training, muscle strength increased slightly after the year of training and was not preserved 4 years later. In the control group (no training), muscle strength did not change after 1 year and 2 years, but it declined significantly after 4 years.

The results of this study indicate that high-intensity resistance training performed around retirement age preserves muscle strength for several years. These results could be useful for coaches, health professionals, and policy-makers as a way to encourage older adults to engage in high-intensity resistance exercise.