Heart Rate and Autonomic Balance During Stand Tests Before and After Fighter Combat Missions

Abstract

Modulations of autonomic balance differed with the type of mission. A postflight sympathetic increase represents an autonomic adaptation due to stress and flight. A raise of parasympathetic modulation after flight may be related to the decrease of alertness.

Monitoring stress and allostatic load in first responders and tactical operators using heart rate variability: a systematic review

“…Mixed results were observed in time and frequency domain measures when comparing baseline HRV to immediately post stressor. Of these studies, eight of fourteen reported decreases in RMSSD [ 58 , 61 , 62 , 68 , 70 , 73 – 75 ], five of seven reported decreases in HF [ 69 , 70 , 73 – 75 ], four of seven reported increases in LF [ 69 , 70 , 74 , 75 ], and five of nine reported increases in LF/HF ratio [ 30 , 70 – 73 ] from baseline to immediately post the stressor. Stressors of a greater magnitude induced a greater suppression of LF and HF [ 76 ].…”

“…Frequency domain metrics mirrored time domain metrics for the most part, with the exception of one study [ 72 ]. Dussalt et al reported an opposite response to all other studies with a reduction in standing HRV occurring in the time course post the completion of the long flight task (~ 4.5 h) in military pilots [ 30 ]. Scheduled recovery days following a 24 h work period showed increases in HRV for rescuers [ 78 ] and ambulance personnel with many self-reported health complaints but not in those with few self-reported health complaints [ 77 ].…”

“… HF n.u. LF/HF SD1 SD2 Strahler & Ziegert [ 62 ] 20 mins post to baseline 50 ↔* ↔ 20 mins post to stress ↑* ↑ 20 mins post to immediately post ↑* ↑ Clemente-Suárez et al [ 54 ] 30 mins post to baseline 38 ↓ ↑ ↓ 30 mins post to stress ↔ ↔ ↔ Ghazali et al [ 73 ] 45 mins post to immediately post 48 ↔ ↔ ↔ 75 mins post to 45 mins post ↑ ↑ ↔ Dussault et al [ 30 ] 2 & 4 h post to baseline 7 Short flight supine ↔↔ ↔↔ ↔↔ Short flight standing ↔↔ ↔↑ <...>…”

“…Only two studies observed HRV at the same time intervals post stressor, complicating study comparisons (see Table 3 ). However, it is clear that the removal of the stressful stimuli results in a gradual return of HRV metrics to baseline levels [ 30 , 54 , 62 , 72 , 78 ]. The rate of return of HRV to baseline appears to be dependent on the magnitude of the stressor individuals were exposed to.…”

Heart Rate and Cardiovascular Responses to Commercial Flights: Relationships with Physical Fitness

“…Consideration of both linear and non-linear HRV measures could be especially important during ambulatory conditions in which the validity and reproducibility of these measures could be different depending on different factors as physical activity levels or sample characteristics (Hautala et al, 2010; Tonello et al, 2015). Previous studies with military pilots demonstrated important HRV and autonomic adjustments during flights (Dussault et al, 2009; Oliveira-Silva and Boullosa, 2015). These flight-induced autonomic changes may trigger several physiological adjustments to maintain homeostasis during a potentially detrimental activity (McEwen and Seeman, 1999).…”