Fig. 9. Rate of force generation and force generation per meter distance during running (2.7 m s^–1) for the examined groups. Values are means ± S.D. of both legs. O, older adults; Y, young adults. Asterisks indicate statistically significant differences between older and young adults: *P<0.05, **P<0.01; there was no age-by-running activity interaction for the analysed parameters (P>0.05).