Macdermid Paul W, Fink Philip W, Miller Matthew C, Stannard Stephen
a College of Health, School of Sport & Exercise , Massey University , Palmerston North , New Zealand.
J Sports Sci. 2017 Jul;35(14):1355-1363. doi: 10.1080/02640414.2016.1215493. Epub 2016 Aug 2.
Non-propulsive work demand has been linked to reduced energetic economy of cross-country mountain biking. The purpose of this study was to determine mechanical, physiological and performance differences and observe economy while riding a downhill section of a cross-country course prior to and following the metabolic "load" of a climb at race pace under two conditions (hardtail and full suspension) expected to alter vibration damping mechanics. Participants completed 1 lap of the track incorporating the same downhill section twice, under two conditions (hardtail and full suspension). Performance was determined by time to complete overall lap and specific terrain sections. Power, cadence, heart rate and oxygen consumption were sampled and logged every second while triaxial accelerometers recorded accelerations (128 Hz) to quantify vibration. No differences between performance times (P = 0.65) or power outputs (P = 0.61) were observed while physiological demand of loaded downhill riding was significantly greater (P < 0.0001) than unloaded. Full suspension decreased total vibrations experienced (P < 0.01) but had no effect on performance (P = 0.97) or physiological (P > 0.05) measures. This study showed minimal advantage of a full suspension bike in our trial, with further investigations over a full race distance warranted.
非推进性工作需求与越野山地自行车能量经济性降低有关。本研究的目的是确定在两种预期会改变减震力学的条件（硬尾车和全避震车）下，在以比赛速度爬坡的代谢“负荷”之前和之后，骑行越野赛道下坡路段时的机械、生理和性能差异，并观察经济性。参与者在两种条件（硬尾车和全避震车）下，完成包含相同下坡路段的一圈赛道两次。通过完成整圈和特定地形路段的时间来确定性能。每秒采样并记录功率、踏频、心率和耗氧量，同时三轴加速度计记录加速度（128Hz）以量化振动。在负载下坡骑行的生理需求显著高于无负载（P < 0.0001）的情况下，未观察到性能时间（P = 0.65）或功率输出（P = 0.61）的差异。全避震减少了所经历的总振动（P < 0.01），但对性能（P = 0.97）或生理指标（P > 0.05）没有影响。本研究表明在我们的试验中全避震自行车优势极小，有必要在完整比赛距离上进行进一步研究。
