Training load does not affect detraining's effect on muscle volume, muscle strength and functional capacity among older adults

Research underlines the potential of low-load resistance exercise in older adults. However, while the effects of detraining from high-load protocols have been established, it is not known whether gains from low-load training would be better/worse maintained. The current study evaluated the effects of 24 weeks of detraining that followed 12 weeks of high- and low-load resistance exercise in older adults. Fifty-six older adults (68.0 ± 5.0 years) were randomly assigned to leg press and leg extension training at either HIGH load (2 × 10-15 repetitions at 80% of one-repetition maximum (1-RM)), LOW load (1 × 80-100 repetitions at 20% of 1-RM), or LOW + load (1 × 60 repetitions at 20% of 1-RM, immediately followed by 1 × 10-20 repetitions at 40% 1-RM). All protocols ended with volitional fatigue. The main outcome measures included mid-thigh muscle volume, leg press 1-RM, leg extension isometric and isokinetic strength, and functional performance. Tests were performed at baseline, post-intervention and after 24 weeks of detraining. Results show no effect of load on preservation of muscle volume, which returned to baseline after detraining. Training-induced gains in functional capacity and isometric strength were maintained, independent of load. HIGH and LOW + were more beneficial than LOW for long-lasting gains in training-specific 1-RM. To conclude, gains in muscle volume are reversed after 24 weeks of detraining, independent of load. This emphasises the need for long-term resistance exercise adherence. The magnitude of detraining in neuromuscular and functional adaptations was similar between groups. These findings underline the value of low-load resistance exercise in older age. Clinical Trial Registration NCT01707017.