Metabolic and mechanical involvement of arms and legs in simulated double pole skiing

Abstract

We evaluated arm and leg work rate and metabolism during double pole ergometer skiing. Thermodilution arm and leg blood flow was determined together with the arterial to venous difference for oxygen, while the work rate was assessed in eight male recreational skiers [24 (SD 7) years]. When work rate increased from 82 (SE 4) to 117 (7) W, leg power increased by 43% (enhanced vertical force and displacement of the body). The elbow angle tended to increase [from 71 (11.3)° to 75 (10.9)°; P = 0.07] and arm oxygen uptake increased by 20 (5)% [from 0.65 (0.07) to 0.78 (0.08) L/min; P < 0.05] because two-arm blood flow increased [from 5.4 (0.6) to 6.3 (0.7) L/min; P < 0.05] with no significant change in oxygen extraction [from 59 (2.3)% to 60 (1.9)%] accompanied with net arm lactate and potassium release. In contrast, two-leg blood flow [from 5.8 (0.5) to 8.0 (0.5) L/min] and oxygen extraction [from 67 (1.3)% to 75 (1.5)%] increased (P < 0.05), resulting in a 53 (8)% increase in leg oxygen uptake [from 0.82 (0.06) to 1.24 (0.07) L/min; P < 0.05]. In conclusion, during double poling on an ergometer, arm muscle metabolism and work rate increase only marginally and an increase in work intensity is covered mainly by the leg muscles.

The Influence of Pole Length on Performance, O2 Cost, and Kinematics in Double Poling

“…As the upper body has been calculated to represent ~ 67% of the body mass in elite crosscountry skiers, 23 considerable work is done by the muscles in the lower limbs in order to extend the upper body to an upright position during the reposition phase. 5,[8][9][10] This is also supported by a previous study that associated high-level skiers` superior exercise economy compared to slower skiers with such a biomechanical strategy. 11 Altogether, our findings imply that less up-and-down vertical movement of the COM during the cycle is beneficial for reducing the O2-cost and maybe even for performance in DP.…”

“…[4][5][6][7][8][9][10][11] Therefore, the pole characteristics are of special interest in DP, 12,13 with pole length being one of the obvious parameters that could influence DP performance. Since the pole length used in a competition needs to be a compromise between the optimal lengths used in the different sub-techniques and terrains, knowledge about the specific effects of pole length on performance would be beneficial to cross-country skiers.…”

Changes in upper and lower body muscle involvement at increasing double poling velocities: an ecological study

“…Since upper limb muscles have reduced muscle mass and oxidative capacity, a greater involvement of the larger sized, more oxygen and lactate-consuming muscles of trunk and lower limbs (Mygind, 1995;Calbet et al, 2005;Holmberg et al, 2007;Rud et al, 2014) allow cross-country skiers to sustain increasing double poling work intensities, by improving the capacity to exert propulsive power during a progressively shorter poling phase. Rud et al (2014) found that the oxygen extraction capacity and mechanical contribution of upper limb muscles do not raise significantly when passing from low to moderate ergometer double poling, while lower limb muscular blood flow, oxygen extraction capacity, and work rate increase considerably. Our study confirms previous findings via an EMG evaluation of double poling in ecological conditions.…”

Constant infusion transpulmonary thermodilution for the assessment of cardiac output in exercising humans

“…The limitations and advantages of the CITT method are similar to those previously mentioned in regard to the BTD method (Calbet & Boushel, ). CITT is an invasive procedure requiring femoral artery and vein catheterization and suitable for experiments with planned catheterizations (Stoggl et al., ; Rud et al., ).…”

“…Since today's gold standard method for the assessment of skeletal muscle during dynamic whole body exercise in humans is the constant infusion thermodilution method (Andersen & Saltin, ), CITT could be utilized in these types of experiments just by inserting a thermistor‐coated catheter rather than an ordinary arterial catheter into the femoral artery. This setup would allow the simultaneous assessment of leg blood flow and cardiac output, enhancing the quality of the hemodynamic information obtained from invasive experiments with planned arterial catheterizations (Rud et al., ). In cases where both methods (BTD and CITT) are used, the CITT can replace failed BTD assessments.…”