A laboratory test was developed to study the metabolic and gas exchange effects of arm, leg and combined arm and leg work. The test incorporated movement patterns similar to those used in cross-country skiing. The work rate for the arm test at maximal effort was 33% (125 watts) and the leg test was 81% (302 watts) of that for the combined test (375 watts). The maximum oxygen uptake (VO2 max) was not significantly different when comparing the leg test to the combined test, but VO2 at submaximal work levels was significantly less during the combined test. The anaerobic threshold (AT) occurred at 68, 73 and 76% of VO2 max for the arm, leg, and combined test, respectively. Although there were no significant differences in VO2 and percent of VO2 max, at the AT between the leg test and the combined test, AT was significantly delayed with respect to time and work rate in the latter condition. Application of these results to cross-country skiing supports the proposal for greater upper body involvement in skiing.