Institute of Sports Science and Innovation, Lithuanian Sports University, 44221 Kaunas, Lithuania.
Institute of Physical Performance, Norwegian School of Sport Sciences, 0863 Oslo, Norway.
Int J Environ Res Public Health. 2020 Mar 22;17(6):2097. doi: 10.3390/ijerph17062097.
Adolescent athletes are particularly vulnerable to stress. The current study aimed to monitor one of the most popular and accessible stress markers, heart rate variability (HRV), and its associations with training load and sleep duration in young swimmers during an 11-week training period to evaluate its relevance as a tool for monitoring overtraining. National-level swimmers (n = 22, age 14.3 ± 1.0 years) of sprint and middle distance events followed individually structured training programs prescribed by their swimming coach with the main intention of preparing for the national championships. HRV after awakening, during sleep and training were recorded daily. There was a consistent ~4.5% reduction in HRV after 3-5 consecutive days of high (>6 km/day) swimming volume, and an inverse relationship of HRV with large (>7.0 km/day) shifts in total training load (r = -0.35, < 0.05). Day-to-day HRV did not significantly correlate with training volume or sleep duration. Taken together, these findings suggest that the value of HRV fluctuations in estimating the balance between the magnitude of a young athlete's physical load and their tolerance is limited on a day-to-day basis, while under sharply increased or extended training load the lower HRV becomes an important indicator of potential overtraining.
青少年运动员特别容易受到压力的影响。本研究旨在监测一种最受欢迎和易于获取的压力标志物，即心率变异性（HRV），并在 11 周的训练期间，将其与年轻游泳运动员的训练负荷和睡眠时间相关联，以评估其作为监测过度训练的工具的相关性。参加研究的是国家一级的短跑和中距离游泳运动员（n = 22，年龄 14.3 ± 1.0 岁），他们按照游泳教练制定的个性化结构训练计划进行训练，主要目的是为全国锦标赛做准备。每天记录觉醒后、睡眠中和训练中的 HRV。在连续 3-5 天高（>6 公里/天）游泳量后，HRV 持续下降约 4.5%，HRV 与总训练负荷的大（>7.0 公里/天）变化呈反比（r = -0.35，<0.05）。HRV 与训练量或睡眠时间无显著相关性。总的来说，这些发现表明，在估计年轻运动员身体负荷的大小与其耐受能力之间的平衡方面，HRV 波动的价值在日常基础上是有限的，而在训练负荷急剧增加或延长的情况下，较低的 HRV 成为潜在过度训练的重要指标。
