Carlsson Tomas, Fjordell Wilma, Wedholm Lars, Swarén Mikael, Carlsson Magnus
School of Health and Welfare, Dalarna University, Falun, Sweden.
Swedish Unit for Metrology in Sports, Dalarna University, Falun, Sweden.
Front Sports Act Living. 2022 May 18;4:850541. doi: 10.3389/fspor.2022.850541. eCollection 2022.
The purpose of the study was to investigate whether there are energy-efficiency differences between the execution of the old-fashioned double-poling technique (DP) and the modern double-poling technique (DP) at a submaximal work intensity among elite male cross-country skiers. Fifteen elite male cross-country skiers completed two 4-min tests at a constant mechanical work rate (MWR) using the DP and DP. During the last minute of each test, the mean oxygen uptake (VO) and respiratory exchange ratio (RER) were analyzed, from which the metabolic rate (MR) and gross efficiency (GE) were calculated. In addition, the difference between pretest and posttest blood-lactate concentrations (BLa) was determined. For each technique, skiers' joint angles (i.e., heel, ankle, knee, hip, shoulder, and elbow) were analyzed at the highest and lowest positions during the double-poling cycle. Paired-samples -tests were used to investigate differences between DP and DP outcomes. There were no significant differences in either VOmean, MR, GE, or BLa (all > 0.05) between the DP and DP tests. DP execution was associated with a higher RER ( < 0.05). Significant technique-specific differences were found in either the highest and/or the lowest position for all six analyzed joint angles (all < 0.001). Hence, despite decades of double-poling technique development, which is reflected in the significant biomechanical differences between DP and DP execution, at submaximal work intensity, the modern technique is not more energy efficient than the old-fashioned technique.
本研究的目的是调查在精英男子越野滑雪运动员次最大运动强度下，传统双杖技术（DP）和现代双杖技术的执行之间是否存在能量效率差异。15名精英男子越野滑雪运动员以恒定机械功率（MWR）使用DP和DP完成了两项4分钟测试。在每次测试的最后一分钟，分析平均摄氧量（VO）和呼吸交换率（RER），并据此计算代谢率（MR）和总效率（GE）。此外，还测定了测试前和测试后血乳酸浓度（BLa）的差异。对于每种技术，分析了滑雪者在双杖周期最高和最低位置时的关节角度（即脚跟、脚踝、膝盖、臀部、肩膀和肘部）。使用配对样本t检验来研究DP和DP结果之间的差异。DP和DP测试之间在VOmean、MR、GE或BLa方面均无显著差异（均P>0.05）。DP的执行与较高的RER相关（P<0.05）。在所有六个分析的关节角度的最高和/或最低位置均发现了显著的技术特异性差异（均P<0.001）。因此，尽管双杖技术经过了数十年的发展，这体现在DP和DP执行之间的显著生物力学差异上，但在次最大运动强度下，现代技术并不比传统技术更节能。
