Younes Mohamed, Robert Céline, Barrey Eric, Cottin François
CIAMS, Université Paris-Sud, Université Paris-SaclayOrsay, France; CIAMS, Université d'OrléansLoiret Orléans, France.
GABI, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-SaclayJouy-en-Josas, France; Ecole Nationale Vétérinaire d'Alfort, Université Paris-EstMaisons-Alfort, France.
Front Physiol. 2016 May 2;7:155. doi: 10.3389/fphys.2016.00155. eCollection 2016.
Although cardiac recovery is an important criterion for ranking horses in endurance competitions, heart rate variability (HRV) has hardly ever been studied in the context of this equestrian discipline. In the present study, we sought to determine whether HRV is affected by parameters such as age, exercise duration and test site. Accordingly, HRV might be used to select endurance horses with the fastest cardiac recovery. The main objective of the present study was to determine the effects of age, exercise duration, and test site on HRV variables at rest and during exercise and recovery in young Arabian endurance horses. Over a 3-year period, 77 young Arabian horses aged 4-6 years performed one or more exercise tests (consisting of a warm-up, cantering at 22 km.h(-1)and a final 500 m gallop at full speed) at four different sites. Beat-to-beat RR intervals were continuously recorded and then analyzed (using a time-frequency approach) to determine the instantaneous HRV components before, during and after the test. At rest, the root-mean-square of successive differences in RR intervals (RMSSD) was higher in the 4-year-olds (54.4 ± 14.5 ms) than in the 5-or 6-year-olds (44.9 ± 15.5 and 49.1 ± 11.7 ms, respectively). During the first 15 min of exercise (period T), the heart rate (HR) and RMSSD decreased with age. In 6-year-olds, RMSSD decreased as the exercise duration increased (T: 3.0 ± 1.4 vs. 2T: 3.6 ± 2.2 vs. 3T: 2.8 ± 1.0). During recovery, RMSSD was negatively correlated with the cardiac recovery time (CRT) and the recovery heart rate (RHR; R = -0.56 and -0.53, respectively; p < 0.05). At rest and during exercise and recovery, RMSSD and several HRV variables differed significantly as a function of the test conditions. HRV in endurance horses appears to be strongly influenced by age and environmental factors (such as ambient temperature, ambient humidity, and track quality). Nevertheless, RMSSD can be used to select endurance horses with the fastest cardiac recovery.
尽管心脏恢复情况是耐力赛中马匹排名的一项重要标准，但心率变异性（HRV）在这项马术赛事中的研究却几乎从未开展过。在本研究中，我们试图确定HRV是否受年龄、运动时长和测试场地等参数的影响。因此，HRV或许可用于挑选心脏恢复速度最快的耐力赛马匹。本研究的主要目的是确定年龄、运动时长和测试场地对年轻阿拉伯耐力赛马匹静息、运动及恢复期间HRV变量的影响。在3年时间里，77匹4至6岁的年轻阿拉伯马在4个不同场地进行了一项或多项运动测试（包括热身、以22 km/h的速度慢跑以及最后500米的全速疾驰）。逐搏RR间期被持续记录，然后进行分析（采用时频分析法）以确定测试前、测试期间和测试后的瞬时HRV成分。静息时，4岁马的RR间期逐搏差值的均方根（RMSSD）（54.4±14.5毫秒）高于5岁或6岁马（分别为44.9±15.5毫秒和49.1±11.7毫秒）。在运动的前15分钟（时期T），心率（HR）和RMSSD随年龄增长而下降。在6岁马中，RMSSD随运动时长增加而下降（T：3.0±1.4对2T：3.6±2.2对3T：2.8±1.0）。恢复期间，RMSSD与心脏恢复时间（CRT）和恢复心率（RHR）呈负相关（分别为R = -0.56和-0.53；p < 0.05）。在静息、运动及恢复期间，RMSSD和其他几个HRV变量因测试条件的不同而有显著差异。耐力赛马匹的HRV似乎受年龄和环境因素（如环境温度、环境湿度和赛道质量）的强烈影响。尽管如此，RMSSD可用于挑选心脏恢复速度最快的耐力赛马匹。
