Training History, Cardiac Autonomic Recovery from Submaximal Exercise and Associated Performance in Recreational Runners

Abstract

This study investigated the effect of prolonged exertion on cardiac parasympathetic (cPS) reorganization and associated aerobic performance in response to repeated short-lasting submaximal exercise bouts (SSE) performed for 7 days following prolonged exertion. In 19 recreational runners, heart rate (HR) and HR variability (HRV) indices (lnRMSSD, lnHF, and lnLF/HF) were monitored pre- and post-submaximal graded cycling performed on consecutive days following a half-marathon (HM) and compared with the baseline, pre-HM values. Additionally, HR recovery (HRR), aerobic performance, and rate of perceived exertion (RPE) were determined. HR, HRV indices, and HRR were tested for correlation with exercise performance. A significant time effect was found in HR, HRR, and HRV indices as well as in aerobic performance and RPE during the study period. Most of the measured parameters differed from their baseline values only on the same day following HM. However, HRR and HR measured in recovery after SSE were additionally affected one day following the half-marathon yet in opposite directions to those recorded on the same day as the HM. Thus, postSSE HR and HRR exhibited a bivariate time response (postSSE HR: 102 ± 14 bpm; p < 0.001; 82 ± 11 bpm; p = 0.007 vs. 88 ± 11 bpm; HRR in 30 s after SSE cessation: 14.9 ± 4.9 bpm; p < 0.001; 30.1 ± 13.3 bpm; p = 0.006 vs. 24.4 ± 10.8 bpm), potentially indicating a cPS dysfunction phase on the same day and cPS rebound phase one day following HM reflected also in consecutive changes in aerobic power. Correlations were found between the changes in measured cardiac indices with respect to baseline and the changes in aerobic performance indices throughout the study period. The effect of exercise history on cPS reorganization is more pronounced in response to SSE than at rest. Accordingly, we conclude that SSE performed repeatedly on a daily basis following prolonged exertion offers a noninvasive tool to evaluate the impact of training history on cPS recovery and associated aerobic power output in recreational athletes.

The Effect of Submaximal Exercise on Cutaneous Blood Flow, Thermoregulation and Recovery Hemodynamics Following Endurance Exercise

“…Consequently, we can probably assume that increased oxidative stress immediately after EEE induces endothelial dysfunction with the impairment of NO availability. Immediately after a half marathon, the response of the cardiovascular system to short lasting aerobic exercise has been shown to mimic the response found in cardiovascular dysfunction (2). Thus, Southeastern European Medical Journal, 2022; 6 (2) subsequent endothelial dysfunction could be due to cardiovascular dysfunction at that time point.…”

“…Measurement of core temperature during the study protocol would be helpful to determine the magnitude of heat stress induced by endurance exercise compared with shortlasting exercise. Southeastern European Medical Journal, 2022; 6 (2) The proposed mechanisms underlying our results could be better determined if different substances such as bretylium tosylate, an inhibitor of noradrenergic vasoconstriction, and a NO synthase inhibitor (L-NAME) were applied to the skin during the measurement protocol.…”

“…This finding of our study can be applied in practice by encouraging patients with chronic wounds to include occasional endurance exercise in their regular moderate training schedule to increase skin blood flow and accelerate wound healing. We can only suggest a few possible mechanisms responsible for the improvement in cutaneous blood flow 24 hours after EEE: increased sympathetic cholinergic vasodilation as the main mechanism to eliminate excessive heat, increased NO bioavailability due to suppressed oxidative stress 24 hours after EEE (29), the involvement of adenosine receptors that have been shown to prevent the decrease in skin blood flow after exercise (18), or a complex interplay of many physiological processes leading to cardiovascular supercompensation, which probably includes improved skin blood flow observed by many authors after endurance training (2,33,34). Further studies need to be conducted to substantiate these assumptions.…”

“…The term "training recovery" was introduced by Bishop et al as recovery between successive exercise sessions (1). It can be assumed that the CBF response in training recovery is the cumulative result of recovery and exercise, especially when exhaustive endurance exercise (EEE), with its long-term effects on cardiovascular function (2), is included in the training process. There are numerous reports of CBF in the recovery phase after a single exercise session (3)(4)(5)(6)(7) but no one has investigated the CBF response to successive submaximal, short-lasting aerobic exercise (SLAE) sessions following exhaustive exercise on daily basis, although this is a commonly used training regime in recreational athletes.…”

“…After exercise, heart rate (HR) decreases to preexercise levels. The initial, rapid phase of HR recovery caused by parasympathetic reactivation is followed by a secondary, slow decline mediated by continued parasympathetic reactivation and sympathetic withdrawal (2). Several studies have examined the mechanisms underlying these post-exercise autonomic responses and have suggested that exercise-induced thermoregulatory demands play an important role (12).…”