Sleep deprivation reduces vagal tone during an inspiratory endurance task in humans

Abstract

Study Objectives Sleep deprivation alters inspiratory endurance by reducing inspiratory motor output. Vagal tone is involved in exercise endurance. This study aimed to investigate the effect of sleep deprivation on vagal tone adaptation in healthy subjects performing an inspiratory effort. Methods Vagal tone was assessed using Heart Rate Variability normalized units of frequency domain component HF (high frequency) before, at the start, and the end of an inspiratory loading trial performed until exhaustion by 16 volunteers after one night of sleep deprivation and one night of normal sleep, where sleep deprivation reduced the inspiratory endurance by half compared to the normal sleep condition (30 min vs 60 min). Results At rest, heart rate was similar in sleep deprivation and normal sleep conditions. In normal sleep condition, heart rate increased during inspiratory loading task; this increase was greater in sleep deprivation condition. In normal sleep condition, vagal tone increased at the beginning of the trial. This vagal tone increase was absent in sleep deprivation condition. Conclusions Sleep deprivation abolished vagal tone response to inspiratory load, possibly contributing to a higher heart rate during the trial and to a reduced inspiratory endurance. Clinical Trial Registration NCT02725190.

Overnight sleeping heart rate variability of Army recruits during a 12-week basic military training course

“…In alignment, HF power, a frequency domain metric reflective of vagal activity, was significantly increased in week 12 and predominantly responsible for driving the observed reduction in the LF:HF power ratio. This observation contrasts with findings from previous studies demonstrating that in otherwise healthy individuals, prolonged high-volume training demands and/or additional stressors, including compromised sleep, insufficient recovery, and fatigue, are associated with mixed HRV outcomes (Meeusen et al 2013 ; Westphal et al 2021 ; Pichot et al 2002 ). The differing results may be explained by the volume and intensity of the physical training prescribed which significantly increased cardiorespiratory fitness by 7% at week 8.…”

“…RMSSD is presented using msec for ease of physiological interpretation but was analysed after natural logarithmic transformation to achieve normal distribution. (Meeusen et al 2013;Westphal et al 2021;Pichot et al 2002). The differing results may be explained by the volume and intensity of the physical training prescribed which significantly increased cardiorespiratory fitness by 7% at week 8.…”

“…Compared with untrained individuals, participation in cardiorespiratory endurance training has been associated with lower resting HR and increased HRV, indicative of stronger cardiac parasympathetic (vagal) autonomic modulation (Goldsmith et al 1992 ; Seals and Chase 1985 ). In contrast, studies investigating exposure to prolonged high-volume cardiorespiratory endurance training demands or stressors such as compromised sleep, insufficient recovery, and fatigue often demonstrate reduced HRV, although findings are inconsistent (Meeusen et al 2013 ; Westphal et al 2021 ; Pichot et al 2002 ). It is becoming increasingly recognised that HRV responses are dependent on a range of physiological and environmental factors which are difficult to control in applied research settings (Fatisson et al 2016 ), likely influencing previous study outcomes.…”

Effects of 24-h acute total sleep deprivation on physiological coupling in healthy young adults

“…Sleep deprivation is associated with a range of negative physiological and psychological outcomes encompassing dysregulation of the autonomic nervous system (ANS), adverse cardiovascular events, and cognitive and complex motor performance impairment. In previous studies, it has been observed that acute total sleep deprivation (ATSD) may decrease parasympathetic cardiac modulation and/or increase sympathetic activity based on heart rate variability (HRV) analysis ( Zhong et al, 2005 ; Chen et al, 2013 ; Glos et al, 2014 ; Virtanen et al, 2015 ; Westphal et al, 2021 ). However, other investigations had contradictory results that accumulation of acute sleep loss resulted in decreased heart rate and increased HRV, which reflects the enhancement of vagal outflow ( Vaara et al, 2009 ; Skurvydas et al, 2021 ).…”

“…Moreover, deprivation of sleep has been known to affect brain functions ( Patrick et al, 2017 ; Hudson et al, 2020 ; Garbarino et al, 2021 ; Grèzes et al, 2021 ). In addition, recent studies reported a decrease in respiratory motor output by altering its cortical component with a subsequent reduction of inspiratory endurance while being deprived of one-night sleep ( Westphal et al, 2021 ). Most of these results suggest that ATSD may have an impact on the cardiovascular, brain, and respiratory systems.…”