Hoshi Daisuke, Fukuie Marina, Tomoto Tsubasa, Qin Wenxing, Tarumi Takashi, Sugawara Jun, Watanabe Koichi
Doctoral Program in Sports Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Japan Society for the Promotion of Science, Tokyo, Japan.
Physiol Rep. 2025 Oct;13(19):e70564. doi: 10.14814/phy2.70564.
Elevated hydrostatic pressure during water immersion reduces lung volume and compliance at rest. These alterations may persist during exercise, influencing both the respiratory regulation and lung volume. This study compared respiratory regulation and lung volume between land-based (LC) and aquatic (AC) cycling matched for oxygen uptake (VO). Ten healthy young adults underwent cycling at low and moderate intensities in both environments. Expiratory gas variables (VO) and respiratory variables (minute ventilation and respiratory rate: V and RR, respectively) were continuously measured using a breath-by-breath gas analyzer system. Ventilatory equivalent for VO (V/VO) was calculated. Using a spirometry system, expiratory and inspiratory reserve volumes (ERV and IRV, respectively), and tidal volume (V) were measured at rest and at each exercise intensity using inspiratory maneuvers and normalized to forced vital capacity (FVC). Although VO was matched between conditions (p > 0.05), AC resulted in significantly higher V, RR, and consequently V/VO at moderate intensity. Additionally, ERV was lower and IRV was higher during AC compared with LC across all intensities, while FVCs remained unchanged in both conditions. These findings suggest a potential mechanism by which exercise in an aquatic environment may be more effective than land-based exercise for training the respiratory system.
水浸过程中升高的静水压力会降低静息时的肺容积和顺应性。这些改变在运动过程中可能持续存在，影响呼吸调节和肺容积。本研究比较了在陆地（LC）和水上（AC）进行的、摄氧量（VO）匹配的骑行运动之间的呼吸调节和肺容积。十名健康的年轻成年人在两种环境下分别进行了低强度和中等强度的骑行。使用逐次呼吸气体分析仪系统连续测量呼气气体变量（VO）和呼吸变量（分钟通气量和呼吸频率，分别为V和RR）。计算VO的通气当量（V/VO）。使用肺量计系统，在静息时以及每种运动强度下，通过吸气动作测量呼气储备量（ERV）和吸气储备量（IRV）以及潮气量（V），并将其标准化为用力肺活量（FVC）。尽管不同条件下VO匹配（p>0.05），但在中等强度时，AC导致V、RR显著更高，因此V/VO也更高。此外，在所有强度下，与LC相比，AC期间ERV更低，IRV更高，而两种条件下FVC均保持不变。这些发现提示了一种潜在机制，通过该机制，在水环境中运动对于训练呼吸系统可能比陆地运动更有效。
