Lifelong Endurance Exercise as a Countermeasure Against Age-Related V˙ O _{2 max} Decline: Physiological Overview and Insights from Masters Athletes

Maximum oxygen consumption (V˙ O _{2 max}) is not only an indicator of endurance performance, but also a strong predictor of cardiovascular disease and mortality. This physiological parameter is known to decrease with aging. In turn, physical exercise might attenuate the rate of aging-related decline in V˙ O _{2 max}, which in light of the global population aging is of major clinical relevance, especially at advanced ages. In this narrative review, we summarize the evidence available from masters athletes about the role of lifelong endurance exercise on aging-related V˙ O _{2 max} decline, with examples of the highest V˙ O _{2 max} values reported in the scientific literature for athletes across different ages (e.g., 35 ml·kg⁻¹·min⁻¹ in a centenarian cyclist). These data suggest that a linear decrease in V˙ O _{2 max} might be possible if physical exercise loads are kept consistently high through the entire life span, with V˙ O _{2 max} values remaining higher than those of the general population across all ages. We also summarize the main physiological changes that occur with inactive aging at different system levels—pulmonary and cardiovascular function, blood O₂ carrying capacity, skeletal muscle capillary density and oxidative capacity—and negatively influence V˙ O _{2 max}, and review how lifelong exercise can attenuate or even prevent most—but apparently not all (e.g., maximum heart rate decline)—of them. In summary, although aging seems to be invariably associated with a progressive decline in V˙ O _{2 max}, maintaining high levels of physical exercise along the life span slows the multi-systemic deterioration that is commonly observed in inactive individuals, thereby attenuating age-related V˙ O _{2 max} decline.