Purpose: To assess the impact of carrying a rifle on the physiological and biomechanical responses of well-trained biathletes.
Methods: Ten elite biathletes (5 men and 5 women) performed ski skating with (R) or without a rifle (NR) on a treadmill using the V2 (5[degrees] incline) and V1 techniques (8[degrees]) at 8 and 6 km[middle dot]h-1, respectively, as well as at racing intensity (~95% of VO2peak, 10.7+/-0.8 and 7.7+/-0.9 km[middle dot]h-1, respectively). Oxygen uptake (VO2), ventilation (VE), heart rate (HR), blood lactate concentration (BLa) and cycle characteristics, as well as pole and leg kinetics were evaluated during these trials.
Results: Metabolic data were all higher for R than NR: VO2 (+2.5%), VE (+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 the 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 ventilation between R and NR was greater for the women than men (P < 0.05), and the difference in blood lactate concentration also tended to be larger for the women (P < 0.1).
Conclusions: Carrying a rifle elevated physiological responses, accelerated cycle rate and involved greater leg work, with no differences between the V1 and V2 techniques.
(C) 2015 American College of Sports Medicine