Stress-recovery correlates of cardiac vagal modulation in women recruit undergoing basic combat police training

Stress disturbs autonomic system balance and is detrimental to the overall quality of life. The objective measurement of stress is challenging as individuals level of perception vary. The indirect assessment of vagal modulation of the heart is a commonly used method to objectively measure perceived stress. The initial recovery characteristics of heart rate after physical exertion reflect the vagal influence of autonomous system on the heart. Timely monitoring of stress symptoms in people involved in maintaining law and order is essential especially when an increase in performance demand is put on them. In this work, women police recruits of Kerala are studied during their tenure in training camp on perceived stress. The objective is to find out whether heart rate recovery has the potential to become a valuable tool to monitor perceived stress in a typical stressful training environment. Stress assessed subjectively via REST-Q 76 questionnaire is analyzed for its association in moderating initial recovery of heart rate after a bout of short duration submaximal physical exertion. In our analysis, higher perceived stress is associated with lower heart rate recovery. 30 and 60s recovery level and slope of recovery curves correlated with many subscales of stress and recovery. Also differences between the magnitudes of correlations as presented by the Steiger's Z value at two different occasions were found to be not significant. Results promise, fast, reliable and economical objective measure of perceived stress which can be applied in field settings. Results also suggest poor reliability of heart rate recovery signals from submaximal exercise in assessing physical fitness may in part be due to its connection with stress and recovery of individuals. This has broad implications for identifying candidates at risk of overtraining, burnout and future adversities.