Poor autonomic control of the heart is associated with increased risk of cardiovascular disease. Previous research indicates that increasing aerobic capacity induce positively autonomic control of the heart (Aubert et al. 2003) regardless of present training load (Buchheit and Gindre 2006). Current training load, however, influences heart rate recovery (HRR) from maximal exercise (Buchheit and Gindre 2006). Previous studies have used middle aged or highly fit populations. Therefore, the aim of the study was to examine the relationship between aerobic capacity, training load, heart rate variability (HRV) and HRR in young, healthy adults. Institutional ethics approval was granted and forty-six healthy non-smoking individuals free from cardiovascular disease participated in the study (age: 21+2.3 years; BMI: 22.8+2.7 kg/m2; %bodyfat: 20.8+7.7%). Autonomic control of the heart was measured non-invasively using HRV analysis of a five minute resting supine electrocardiogram. A physical activity questionnaire assessed training load (Baecke et al. 1982). VO2peak was determined by a maximal incremental cycling test. To determine HRR, seated HR 60 seconds post exercise termination was subtracted from the maximal HR at the end of the maximal test. Correlations were used to determine relationships between Baecke score, VO2peak, HRV variables and HRR. VO2peak was converted to z scores to adjust for sex. Pearson’s correlation was used where data were normally distributed otherwise Spearman’s rank correlation was adopted. A positive relationship was established between Baecke score and sex-adjusted VO2peak (r=0.355, p<0.05). No relationships, however, were found between Baecke score and HRV variables or with HRR. Additionally, VO2peak (z score) was not correlated to HRV variables or HRR. Furthermore, no relationship was found between HRV and HRR. These findings contradict previous studies conducted in older or more highly fit populations suggesting that in a young moderately fit population other factors such as genetic predisposition or prior training may have more influence on HRV and HRR than training load or fitness.
King's College London (2009) Proc Physiol Soc 14, PC45
Poster Communications: Aerobic fitness, activity levels and heart rate variability in young adults.
A. J. Connorton1, V. F. Gladwell1, G. R. Sandercock1
1. Essex University, Colchester, United Kingdom.
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Where applicable, experiments conform with Society ethical requirements.