Strength, Size, and Muscle Quality in the Upper Arm following Unilateral Training in Younger and Older Males and Females

Purpose To assess strength, size, and muscle quality differences between younger and older males and females in response to training. Methods The bicep and tricep of the non-dominant arm were trained for twelve weeks in younger and older males and females (n = 41). The bicep of both arms were assessed pre and post for muscle strength using one-repetition maximum (1 RM) testing, and size using magnetic resonance imaging (MRI). Results Strength (p < 0.05), mCSA (p < 0.05), and 1 RM MQ (p < 0.00) increased in response to training in all subjects regardless of age or gender. Younger and older subjects had similar increases in strength (45.49 ± 15.30% vs. 42.67 ± 26.67% respectively), mCSA (16.22 ± 7.98% vs. 19.17 ± 6.19% respectively), and 1RM MQ (25.73 ± 15.76 vs. 19.67 ± 20.66 respectively). Women increased their strength (55.59 ± 19.45% vs. 32.87 ± 15.66% p < 0.00 respectively), size (20.36 ± 6.29% vs. 14.72 ± 7.28% p < 0.02 respectively), and 1 RM MQ (29.74 ± 18.33% vs. 16.30 ± 15.59% p <.02) more than men. In comparing age and gender, younger females increased their strength more than older males (56.42 ± 12.92% vs. 29.17 ± 21.8% p <.02 respectively). Older females also increased their strength more than older males (54.68 ± 25.73 vs. 29.17 ± 21.80% respectively). Younger females increased their 1 RM MQ more than older males (.18 ± .08 kg/cm vs. .06 ± .08 kg/cm p <.02 respectively). Conclusion Strength and mCSA increases similarly in older and younger subjects. However, the overall strength and quality of the muscle seems to improve more in women than in men