Fig. 1

Resistance training enhanced the muscle strength and cognitive performance in 9-month and 18-month-old mice. a A picture of resistance exercise training apparatus. b A timeline of the experimental interventions. c The water and food intake during the training period. Data represented the averaged values of individual group and were analyzed by repeated measures of two-way ANOVA, followed by Bonferroni test as post hoc comparisons. d The body weight changes in mice from the four different groups in absolute values and e in grams gained or lost. f Muscle strength scores at baseline and after resistance exercise in absolute values and g in terms of points gained or lost. The score was calculated by the formula: [3 × (heaviest weight − 40 g) + (time held)]. Body weight and muscle strength values were analyzed by paired Student’s t-tests, paired with baseline. Body weight and muscle strength changes were analyzed by two-way ANOVA, followed by Tukey multiple comparisons test. h Number of errors in the Y-maze test after training. A higher number of errors indicate poorer performance. i Escape latency in the Y-maze test. A longer latency indicates poorer performance. These were analyzed by two-way ANOVA, followed by Tukey multiple comparisons test. n = 12 for 9M-SED, n = 13 for 9M-RE (except for muscle strength test, one mouse in middle-aged exercise group wounded its front paw on testing day, therefore its data about muscle strength was excluded), n = 11 for 18M-SED and n = 12 for 18M-RE. SED sedentary group, RE resistance exercise group. Data presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001