Relationship between exercise capacity and heart rate variability: Supine and in response to an orthostatic stressor

Abstract

A b s t r a c tThe study investigated whether supine-measured HRV indicators, and/or HRV indicators measured during orthostatic stress are related to conventional measures of exercise and performance ability such as VO 2max . Only two significant correlations (pb0.05) out of 30 tests were found between supinedetermined HRV indicators and conventional measures. In contrast, fifteen of the 30 relationships calculated during orthostatic stress were significant. Relationships were at best low to moderate (0.2b|corr|b0.4). As expected, the relationships obtained during orthostatic stress were reversed from that obtained in the supine position. In summary, although HRV indicators are related to cardiovascular fitness, correlations between VO 2max and these parameters are found only under very specific conditions. HRV parameters explain very little of the variance in VO 2max . In addition, estimating the exercise capacity from HRV indicators requires experience and extreme caution Maximal oxygen uptake (VO 2max ) is widely used as an indicator of exercise capacity and predictor of survival and performance in a variety of clinical and athletic populations (Stelken et al., 1996;Diamond, 2007). VO 2max is normally assessed in a laboratory setting by means of respiratory gas analysis equipment. This method is expensive, time consuming and requires the expertise of qualified laboratory personnel. Currently, an increasing number of studies employ the more accessible resting heart rate variability (HRV) indicators as prognostic indicators of survival in patients and of training status in athletes (Gilliam et al., 2007;Achten and Jeukendrup, 2003). HRV represents the changes in instantaneous heart rate over a segment or the full length of an RR interval recording (tachogram), as controlled by the sympathetic and parasympathetic branches of the autonomic nervous system (ANS) (Task Force, 1996). In this respect HRV analysis is used as a non-invasive indicator of ANS function and window on the clinical or training status of patients and athletes.In testing the assumption that HRV as determined by off-the-shelf HR monitors can be used in place of the more cumbersome and ten times more expensive than VO 2max assessment, correlations were found between resting HRV indicators and VO 2max. However, results are inconsistent and studies reported significant correlations as well as no correlations between VO 2max and the same HRV indicators (Bucheit and Gindre,

A comparison between heart rate and heart rate variability as indicators of cardiac health and fitness

“…Another drawback is that the tachogram used to determine HRV, was sampled only in a resting, supine position. Previous studies indicated that HRV measured during a stressor, such as standing upright, show more significant correlations with cardiopulmonary fitness indicators than supine HRV measurements (Grant et al, 2009 ). For future studies it is recommended to investigate participants from other age groups as well as clinical groups to answer the question whether these results are only applicable to healthy young participants and if not; how it differs in other groups.…”

Resilience to orthostasis and haemorrhage: A pilot study of common genetic and conditioning mechanisms

“…For example, the evaluation of autonomic regulation of the heart rate, which is indicated by its variability changes in response to an orthostatic challenge, has been suggested to predict an individual’s capacity for adaptive responses of the sympathetic nervous system (SNS) 4 5 6 7 8 9 10 11 . However, withdrawal of these adaptive changes or recovery after an orthostatic challenge should be considered an individual’s capacity for resilience or recovery status of the parasympathetic nervous system (PNS) 8 12 13 14 15 16 17 .…”

Repeatability and Reliability of Heart Rate Variability in Healthy, Adult Pony Mares

“…Heart rate variability, referring to the changes in beat to beat heart rate measured over a period of a RR-interval recording (tachogram) [8,9], has been proven as a valid method to assess stress in humans [8] and animals [10], including horses [5,6,[11][12][13][14], pigs [15,16], sheep and goats [17][18][19], cattle [20,21], poultry [22], and dogs [23,24]. Studies in humans showed that standardization of methodology is important to assure inter-and intra-study repeatability of HRV measurements [25][26][27][28][29].…”