Effect of carrying a rifle on physiology and biomechanical responses in biathletes.

Abstract

This study aimed to assess the effect of carrying a rifle on the physiological and biomechanical responses of well-trained biathletes. Ten elite biathletes (five men and five women) performed ski skating with (R) or without a rifle (NR) on a treadmill using the V2 (5° incline) and V1 techniques (8°) at 8 and 6 km·h(-1), respectively, as well as at racing intensity (approximately 95% of peak oxygen uptake (V˙O2peak), 10.7 ± 0.8 and 7.7 ± 0.9 km·h(-1), respectively). V˙O2, ventilation (V˙(E)), HR, blood lactate concentration (BLa), and cycle characteristics as well as pole and leg kinetics were evaluated during these trials. Metabolic data were all higher for R than for NR, as follows: V˙O2, +2.5%; V˙(E), +8.1%; RER, +4.2%; all P < 0.001; HR, +1.7%; and BLa, +15.1%; both P < 0.05. Biomechanically, carrying a rifle reduced cycle time and length, poling and arm swing times, and leg ground contact time and increased cycle rate, the peak and impulse of leg force, average cycle force, and impulse of forefoot force (all P < 0.05). With the exception of elevated pole forces when V2 skating at racing velocity, there were no differences between the peak and impulse of pole force. The difference in V˙(E) between R and NR was greater for the women than that for men (P < 0.05), and the difference in BLa also tended to be larger for the women (P < 0.1). Carrying a rifle elevated physiological responses, accelerated cycle rate, and involved greater leg work, with no differences between the V1 and V2 techniques.