Exercise, Heart Rate Variability, and Longevity

Humans are increasingly approaching an era where cardiovascular health seems to be one of the major upper limits on achievable life span. An increasing body of scientific research and observational evidence indicates that resting heart rate (HR) is inversely related to the life span among homeothermic mammals and within individual species. HR not only reflects the status of the cardiovascular system but also serves as an indicator of cardiac autonomic nervous (sympathetic and parasympathetic) system activity and metabolic rate. There is a remarkable amount of variation in HR among species; it can be as low as 30 to 35 beats per minute (bpm) in large animals like whales and elephants or as high as 600 to 700 bpm in mice (Figure 1). Mammals that have a slower average HR tend to live much longer than those that have a faster HR.1,2 Although some variability inevitably exists and is observed in humans, estimations yield a mean value of ≈1 × 109 (1 billion) heartbeats in a lifetime across almost all homeothermic mammals (Figure 2).Figure 1. Semilogarithmic relation between resting heart rate and life expectancy in 15 mammal species. Excluding humans, heart rate (HR) is inversely correlated with life span. Adapted from Levine1 with permission of the publisher.Figure 2. Relation between life expectancy and total heartbeats over a lifetime of 15 mammal species. Data fall in a relatively narrow range, ≈1 billion beats. Adapted from Levine1 with permission of the publisher.Article see p 2100Regularly engaging in moderate-to-vigorous physical activity has been shown to reduce the risk of all-cause mortality, cardiovascular mortality, cancer mortality, stroke, heart disease, breast cancer, and colon cancer, as well as numerous other undesirable health outcomes.3 Endurance physical exercise can reduce HR and promote the overall health profile. It is well …