Charlton Jesse M, Ramsook Andrew H, Mitchell Reid A, Hunt Michael A, Puyat Joseph H, Guenette Jordan A
1Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, CANADA; 2Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, CANADA; and 3Centre for Health Evaluation and Outcome Sciences, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, CANADA.
Med Sci Sports Exerc. 2017 Dec;49(12):2578-2584. doi: 10.1249/MSS.0000000000001393.
Aerobars place a cyclist in a position where the trunk is flexed forward and the elbows are close to the midline of the body. This position is known to improve cycling aerodynamics and time trial race performance compared with upright cycling positions. However, the aggressive nature of this position may have important cardiorespiratory and metabolic consequences. The purpose of this investigation was to examine the respiratory mechanical, ventilatory, metabolic, and sensory consequences of cycling while using aerobars during laboratory-based cycling.
Eleven endurance-trained male cyclists (age, 26 ± 9 yr; V˙O2peak, 55 ± 5 mL·kg·min) were recruited. Visit 1 consisted of an incremental cycling test to determine peak power output. Visit 2 consisted of 6-min bouts of constant load cycling at 70% of peak incremental power output in the aerobar position, drop position, and upright position while grasping the brake hoods. Metabolic and ventilatory responses were measured using a commercially available metabolic cart, and respiratory pressures were measured using an esophageal catheter.
Cycling in the aerobar position significantly increased the work of breathing (Wb), power of breathing (Pb), minute ventilation, ventilatory equivalent for oxygen and carbon dioxide, and transdiaphragmatic pressure compared with the upright position. Increases in the Wb and Pb in the aerobars relative to the upright position were strongly correlated with the degree of thoracic restriction, measured as the shoulder-to-aerobar width ratio (Wb: r = 0.80, P = 0.01; Pb: r = 0.69, P = 0.04).
Aerobars significantly increase the mechanical cost of breathing and leads to greater ventilatory inefficiency compared with upright cycling. Future work is needed to optimize aerobar width to minimize the respiratory mechanical consequences while optimizing aerodynamics.
空气动力学车把使自行车骑行者处于躯干向前弯曲且肘部靠近身体中线的姿势。与直立骑行姿势相比，已知这种姿势可改善骑行的空气动力学性能并提高计时赛成绩。然而，这种姿势的激进特性可能会产生重要的心肺和代谢影响。本研究的目的是在基于实验室的骑行过程中，研究使用空气动力学车把骑行时的呼吸力学、通气、代谢和感觉影响。
招募了11名耐力训练的男性自行车骑行者（年龄，26±9岁；峰值摄氧量，55±5 mL·kg·min）。第一次访视包括递增骑行测试以确定峰值功率输出。第二次访视包括在空气动力学车把姿势、下伏姿势和直立姿势下，以峰值递增功率输出的70%进行6分钟的恒定负荷骑行，同时握住刹车手柄。使用商用代谢分析仪测量代谢和通气反应，使用食管导管测量呼吸压力。
与直立姿势相比，在空气动力学车把姿势下骑行显著增加了呼吸功（Wb）、呼吸功率（Pb）、分钟通气量、氧通气当量和二氧化碳通气当量以及跨膈压。与直立姿势相比，空气动力学车把姿势下Wb和Pb的增加与胸廓受限程度密切相关，胸廓受限程度以肩到空气动力学车把的宽度比衡量（Wb：r = 0.80，P = 0.01；Pb：r = 0.69，P = 0.04）。
与直立骑行相比，空气动力学车把显著增加了呼吸的机械成本，并导致通气效率更低。未来需要开展工作来优化空气动力学车把的宽度，以在优化空气动力学的同时将呼吸力学影响降至最低。
