Effects of an 8-week resistance training intervention on plantar flexor muscle quality and functional capacity in older women: A randomised controlled trial

The present study examined 8 weeks of resistance training and its effects on muscle quality measures, plantar flexor muscle strength, muscle thickness and functional capacity in older women. Moreover, we tested if changes in muscle quality were associated with functional capacity. Twenty-four older women (66.3 ± 5.8 years; 69.0 ± 3.0 kg; 25.3 ± 1.4 kg·m−2) were recruited to the study. After completion of the baseline assessment, participants were randomly assigned to either the resistance training (RET, n = 12) or an active control group (CTR, n = 12). Muscle quality was evaluated through muscle echo intensity (MQEI) and specific tension (MQST). Muscle thickness, unilateral plantar flexor muscle strength and functional tests were evaluated at baseline and after the training period. After 8 weeks, both MQEI and MQST did not respond to the intervention. Furthermore, significant changes in stair climb performance (P 0.05). Finally, significant gains in muscle hypertrophy were observed in the RET group (P 0.05). In conclusion, a resistance training program provided significant benefits in the stair climb test, unrelated to plantar flexor-derived muscle quality measures as previously demonstrated in quadriceps femoris. •Muscle quality has been considered an important target of resistance exercise.•Muscle quality has been associated with functional capacity.•No investigation has been conducted for calf derived muscle quality.•Resistance training provides significant benefits in stair climb performance.•Gains in stair climb performance were not associated with calf muscle quality.