Correlations between endogenous (A,B) and residual (unrepaired) (C–H) DNA strand breaks with V’O2max. Cells were incubated for 45 (C,D), 60 (E,F), and 75 (G,H) min after irradiation. Linear regression shows a significant correlation between endogenous DNA strand breaks and V’O2max as well as between DNA repair after exhaustive exercise (B,D,F,H) but not before (A,C,E,G). n = 30 subjects in each plot (15 trained and 15 untrained). Statistical significance means a significant linear relationship between x and y. The p values were calculated from an F test and are displayed in each figure.