Autonomic response to exercise as measured by cardiovascular variability

Abstract

Heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) are often used as measures of autonomic activity, even though reported results are not always comparable or as expected. It is known that endurance athletes have lower average resting heart rates than non-exercising individuals. 33,50 However, other exercise-induced autonomic influences on cardiac control are far more controversial.Autonomic control via sympathetic and parasympathetic modulation of the heart has been assessed by power spectral analysis of HRV 1,7,33,41,46,48,50 and BPV. 44,52 Different frequency peaks reflect specific physiological stimuli and it is possible to estimate the involvement of the autonomic nervous system (ANS) influence and balance in heart rate (HR) regulation. Method. An Ovid MEDLINE Database search for the period 1950 -March 2008 produced 46 articles for review. The published articles that evaluate the effect of exercise on the autonomic nervous system (ANS) are summarised in three categories: the response of the ANS during a bout of exercise, directly after exercise (recovery measurements), and after a long-term exercise programme. Results.Articles on the effect of training on the ANS as measured by cardiovascular variability indicators show increased variability, decreased variability, and no change in variability. Conclusion.Findings in this review emphasise that standardisation and refinement of these measuring tools are essential to produce results that can be repeated and used as reference. Standardisation is essential as these measurements are increasingly employed in studies regarding investigations of central autonomic regulation, those exploring the link between psychological pro cesses and physiological functioning, and those indicating ANS activity in response to exercise, training and overtraining. This review shows that important aspects are inter-individual differences, duration and intensity of the exercise programme, and choice and specific implementation of variability analysis techniques. CoRREspondEnCE:Mrs C C Grant Section Sports Medicine University of Pretoria Tel: 27 12 3624496 Fax: 27 12 3623369 E-mail: Rina.Grant@up.ac.za and also gives an indication of respiratory sinus arrhythmia (RSA). 1,48During measurement of systolic BPV the LF peak corresponds with sympathetic activity while the HF peak is determined by mechanical effects of respiration on intrathoracic pressure and cardiac filling. 44,52 The variability in blood pressure and identification of the corresponding physiological stimuli are difficult to identify. Indications are that the very low frequencies (≤0.04 Hz) are influenced by vascular tone, endothelium factors and thermoregulation, and the LF peak (0.07 -0.15 Hz) relates to sympathetic activity and represents vasomotor tone.2 BRS reflects mainly vagal modulation of the HR by the arterial baroreceptors and the magnitude of response in heart beat interval to a change in blood pressure (ms/mmHg). 6Physical exercise requires rapid and complex physio...

Sleep restriction alters physiological and emotional responses to emotion induction

“…Typically, it is assumed that the sympathetic and parasympathetic systems are complementary, and thus, it would be expected that as HF declines, LF (and SCRs) would increase; however, it has been found that fluctuations in the two bands might be on different time scales (Shaffer & Ginsberg, 2017), thereby temporally uncoupling the responses of the two measures. This intriguing pattern has also been reported after steady‐state exercise in healthy participants (Grant & Ker, 2008; Maud & Foster, 2006: p. 52; Povea et al., 2005), suggesting that the combination of sleep restriction and an emotional challenge induces an adaptive response to maintain a constant HR response across WR and SR conditions. This conjecture is also consistent with the decreased self‐reported fatigue when watching the sad film clip in the SR condition.…”

“…This intriguing pattern has also been reported after steady-state exercise in healthy participants (Grant & Ker, 2008;Maud & Foster, 2006: p. 52;Povea et al, 2005), suggesting that the combination of sleep restriction and an emotional challenge induces an adaptive response to maintain a constant HR response across WR and SR conditions. This conjecture is also consistent with the decreased selfreported fatigue when watching the sad film clip in the SR condition.…”

The effects of acute exercise and a nap on heart rate variability and memory in young sedentary adults

“…Although regular or chronic aerobic exercise training increases parasympathetic/vagal modulation of HR with decreased sympathetic tone at rest after recovery (Grant et al., 2008; Michael et al., 2017; Sandercock et al., 2008; Stanley et al., 2013), parasympathetic regulation initially decreases within a few minutes to hours following acute exercise (Buchheit et al., 2007; Stanley et al., 2013). This is due to augmented sympathetic and metaboreflex stimulations that perturb cardiac vagal control (Stanley et al., 2013).…”

“…In addition to sleep, regular exercise training program improves cardiovascular autonomic balance by increasing parasympathetic tone with a concomitant decrease in sympathetic tone at rest after recovery (Abad et al., 2014; Billman, 2002; Grant et al., 2008; Grässler et al., 2021; Sandercock et al., 2008). However, cardiac parasympathetic activity is initially decreased within a few minutes to hours after acute exercise (Stanley et al., 2013), whereas cardiac parasympathetic/vagal activity can return to pre‐exercise levels within 24 to 72 hr or rebound above baseline levels (Grant et al., 2008;Michael et al., 2017; Stanley et al., 2013). The parasympathetic response during exercise and post‐exercise recovery of vagal cardiac modulation is influenced by exercise characteristics (intensity, duration, modality and timing), as well as age and fitness levels of individuals (Grant et al., 2008; Guerra et al., 2014; Michael et al., 2017; Stanley et al., 2013).…”

“…However, cardiac parasympathetic activity is initially decreased within a few minutes to hours after acute exercise (Stanley et al., 2013), whereas cardiac parasympathetic/vagal activity can return to pre‐exercise levels within 24 to 72 hr or rebound above baseline levels (Grant et al., 2008;Michael et al., 2017; Stanley et al., 2013). The parasympathetic response during exercise and post‐exercise recovery of vagal cardiac modulation is influenced by exercise characteristics (intensity, duration, modality and timing), as well as age and fitness levels of individuals (Grant et al., 2008; Guerra et al., 2014; Michael et al., 2017; Stanley et al., 2013). The exercise intensity is the primary factor for determining vagal cardiac modulation responses during exercise and post‐exercise recovery (Michael et al., 2017; Stanley et al., 2013).…”