The purpose of this study was to determine physical capacity, gross efficiency (GE), and physical strain (PS) of 16 male handcycle users during a 10K race, and to relate these to race performance. All subjects used a handcycle system attached to their own wheelchair and were classified into a group with (A1/A2; N=10) and without (A3; N=6) upper-limb impairments. The PS was defined as the mean heart rate during the race, expressed relative to the heart rate reserve (%HRR). Race performance was defined as the mean race velocity (Vrace). Maximal power output (POmax), VO2peak, and GE (at 28 W) were determined in a graded treadmill exercise test. POmax (55+/-25 versus 129+/-26 W), VO2peak (1.11+/-0.4 versus 2.12+/-0.4 L x min(-1)) and Vrace (13.6+/-3 versus 19.9+/-3 km x hr(-1)) were different between A1/A2 and A3 (p<0.001), whereas PS (80+/-9 versus 88+/-9 %HRR; p=0.12) and GE (10.9+/-1.4 versus 9.7+/-0.9%; p=0.09) were not. POmax, VO2peak, and PS were associated (p<0.05) with Vrace (R=0.91, 0.90, and 0.66). Regression analysis showed that after VO2peak, GE added another 9 percent to the explanation of the variance of Vrace (R2=0.89). In conclusion, attainable handcycling POmax is markedly high and strongly related to race performance. The high PS during the race suggests that handcycling is well suited for aerobic training for most groups of wheelchair users.