Energy cost of rifle carriage in biathlon skiing.

Abstract

Since biathlon racing involves cross-country skiing while carrying a minimum weight 3.5-kg rifle, energy cost for rifle carriage could be significant to race outcome. The purposes of this study were to: 1) compare physiological measurements of biathletes roller skiing with and without rifle carriage, 2) compare energy cost of rifle carriage between women and men, 3) examine the relationship of cycle length and cycle rate to energy cost of rifle carriage, and 4) compare physiological measurements to calculated estimates of power requirements of rifle carriage. We examined metabolic cost of rifle carriage during inclined roller ski-skating. National Team Biathletes (7 W, 8 M) performed treadmill roller ski-skating (2.46, 2.68, and 2.91 m.s-1, 8% incline, 5-min stages) with and without a 3.65 kg rifle. For W, HR, VO2, and VE during carriage were higher at all speeds, LA was higher at the fastest speed (P < 0.05). For M, VO2 and VE were higher at all speeds, HR and LA were higher at 2.68 and 2.91 m.s-1 (P < 0.05). Rifle mass as percent of body mass was different between W and M (6.6 +/- 0.7% vs 5.0 +/- 0.3%, P < 0.05). Percent increase in VO2 (2.1% and 1.3% per kg load; for W and M, respectively) was not different than rifle mass as percent body wt. Cycle length was related to increased VO2 and LA during rifle carriage for W (r = -0.59 and -0.70 to -0.85), and to LA for M (r = -0.66 to -0.83). The large range in cost between individuals (0.2 +/- 0.08 and 0.19 +/- 0.17 L.min-1; for W & M, respectively) suggests that individual economies for load carriage can be improved.