Fig. 2

Fatigue ratio (a) and Recovery ratio (b) ME/CFS patients as well as female CRF patients showed higher Fatigue Ratios in both sessions and lower Recovery Ratios compared to HC. Ten repeat measurements of maximal HGS were performed in two sessions (60-min interval) by a hand dynamometer (in kg). Fatigue Ratio = (Fmax/Fmean), Recovery Ratio = (Fmean2/Fmean1). Left: female ME/CFS patients (circles, n = 61), CRF patients (triangles, n = 18) and HC (squares, n = 36), right: male ME/CFS patients (circles, n = 44) and HC (squares, n = 30). Boxplots (10–90 Percentile), ns = p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 (Mann–Whitney-Test)