Effects Of Equal-volume Resistance Training With Different Intensity On Muscle Quality In Prediabetes Elders.

Abstract

Aging is accompanied by a progressive decline in skeletal muscle system. These problems could increase the risks of chronic diseases, falls, and mortality. Resistance training (RT) is an effective strategy to enhance muscle strength, mass, and quality in older populations. However, few studies have examined the influence of different resistance training intensity on skeletal muscle system in prediabetes elders. PURPOSE: The present study is to investigate the effects of high-intensity versus low-intensity RT on muscle strength, body composition, muscle quality, and functional capacity in older adults with prediabetes. METHODS: Twenty-five prediabetes elders (67 ± 4 yrs) were randomized into 1 of 2 groups: high intensity RT (HIGH, 3 × 8 × 80% of 1RM, n = 13) and low intensity RT (LOW, 3 × 16 × 40% of 1RM, n = 12). The 8-week RT program performed 3d·wk-1, using 8 exercises for the whole body. Anthropometric, muscle strength, body composition, muscle quality, and functional capacity were measured pre- and post-training. RESULTS: No significant difference was observed in body composition in both groups (p > 0.05). Both groups presented significant improvement for functional capacity (grip strength, time up and go test and 30-second chair stand; p < 0.05) with no difference between groups (p > 0.05). The HIGH showed significant improvements in muscle strength compared with the LOW (p < 0.05) for total 1RM (HIGH = 22.9%; LOW = 15%), seated row 1RM (HIGH = 24.2%; LOW = 9.9%), back extension 1RM (HIGH = 29%; LOW = 17.5%), leg curl 1RM (HIGH = 22.3%; LOW = 13.7%), leg press 1RM (HIGH = 20.4%; LOW = 11.6%), total muscle quality (HIGH = 21.3%; LOW = 11.8%), upper muscle quality (HIGH = 22.6%; LOW = 12.8%), and lower muscle quality (HIGH = 21.8%; LOW = 11.2%). CONCLUSION: These results suggest that both HIGH and LOW, characterized by the same training volume, improve functional capacity and maintain body composition, whereas HIGH is superior for enhancing muscle strength and muscle quality in older adults with prediabetes.