Twenty-five percent of individuals with prediabetes progress to type 2 diabetes within 3–5 years, and up to 70% of individuals with prediabetes develop diabetes within their lifetime.1 Diabetes increases the risk of disability in older adults. Lifestyle-based interventions have been demonstrated to be effective in improving physical function. The American Diabetes Association recommends that patients with prediabetes or diabetes engage in moderate-to-vigorous physical activity to preserve and increase muscle strength and mass.2 Aging is accompanied by a progressive loss of skeletal muscle strength, mass, and quality.3 Muscle quality, defined as muscular strength per unit of muscle mass, is positively associated with mortality risk,4 poor performance, and falls.5 Both hyperglycemia and aging can impair skeletal muscle function. One study reported that aging-associated loss of skeletal muscle function is more severe in adults with hyperglycemia than normoglycemic individuals.6

Resistance training (RT) with supervision is a safe and effective approach to enhance muscle strength, mass and quality,7,8 and thereby to ameliorate aging-associated loss of skeletal muscle function. A systematic review and meta-analysis confirmed dose-response relationships for training intensity in healthy older adults, indicating that the largest gain in muscle strength was for a training load of 70–79% 1RM.8 Nevertheless, the effects of differential RT loads on muscle strength and the quality of upper and lower-limb muscles are under investigated in the prediabetic population. Prevention research is required to determine the optimal RT prescriptions for older adults with prediabetes.

This study examined the effect of high-load (80% 1RM) and low-load (40% 1RM) RT with equal training volume on body composition, functional capacity, muscle strength, and muscle quality to inform clinical practice and the development of effective RT prescriptions for older adults with prediabetes. Lighter loads may be particularly suitable for older adults with prediabetes who are concerned with the possibility of injury or prefer less challenging loads.