Ronald E. De Meersman

Heart rate variability and aerobic fitness

Heart rate variability, a noninvasive marker of parasympathetic activity, diminishes with aging and is augmented after exercise training. Whether habitual exercise over time can attenuate this loss is unknown. This cross-sectional investigation compared 72 male runners, aged 15 to 83 to 72 age- and weight-matched sedentary control subjects for the amplitude of their heart rate variability. Heart rate variability was assessed during rest while subjects were breathing at a rate of 6 breaths per minute and at an augmented tidal volume (tidal volume = 30% of vital capacity). Fitness levels were assessed with on-line, open-circuit spirometry while subjects were performing an incremental stress test. Overall results between the two groups showed that the physically active group had significantly higher fitness levels (p < 0.001), which were associated with significantly higher levels of heart rate variability, when compared with their sedentary counterparts (p < 0.001). These findings provide suggestive evidence for habitual aerobic exercise as a beneficial modulator of heart rate variability in an aging population.

Vagal modulation and aging.

Cardiovascular disease accounts for approximately 30% of all deaths worldwide, and will only worsen as the worlds population ages. It is well-established that age, per se, is a major risk factor and contributor to all cardiovascular morbidities and mortalities. However, environmental factors, including a lack of exercise, appear to play a critical role in the onset and progression of cardiovascular disease. This paper reviews the literature on cardiac variability and aging and addresses risk factors associated with aging that can be modified and possibly attenuate the decline of heart rate variability with aging, including exercise training to increase vagal modulation. Thus, results of the studies described in this review support a potential benefit of increasing or maintaining fitness in order to slow the decline of parasympathetic control of HR with normal aging.

Respiratory sinus arrhythmia alteration following training in endurance athletes

SummarySignificant increases in maximum oxygen consumption (

Cardiac autonomic responses to progressive head-up tilt in individuals with paraplegia

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Transient suppression of heart rate complexity in concussed athletes

) were noted in nine young track athletes following an 8-week high-intensity running period (P < 0.05).

Increased QT Interval Variability in 3 Recently Concussed Athletes: An Exploratory Observation

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