VO2 max and muscle mass emerge as top predictors of longevity, surgeon says

Two measurable physiologic markers — VO2 max, a metric of cardiorespiratory fitness, and overall muscle mass — may be among the strongest predictors of how long a person will live, Dr. Jeremy London, a board-certified cardiovascular surgeon, said in remarks and a social media video this week.

VO2 max reflects how efficiently the body uses oxygen during intense exercise and is widely regarded as an indicator of cardiovascular health. "In other words, the health of your cardiovascular system," London said in the video. In an on-camera interview with Fox News Digital, he described VO2 max as "statistically" the No. 1 indicator of longevity.

Scientific literature has linked higher VO2 max to lower rates of cardiovascular disease and mortality. Researchers who compare groups with differing levels of cardiorespiratory fitness consistently find reductions in cardiovascular morbidity and death among those with higher VO2 max, according to summaries of the evidence cited by clinicians and public health experts.

Muscle mass is the second metric London highlighted. Greater muscle mass helps maintain strength and mobility and reduces the risk of frailty, falls and loss of independence as people age. Clinicians say maintaining muscle also influences metabolic health, including glucose regulation and basal energy expenditure, which can affect chronic disease risk.

Both markers are largely modifiable through lifestyle interventions. Aerobic exercise, particularly activities that raise heart rate for sustained periods, improves VO2 max; high-intensity interval training has been shown in research to produce meaningful gains in cardiorespiratory fitness for many people. Resistance training and progressive strength work increase skeletal muscle mass and preserve function, especially when combined with adequate protein intake and overall caloric support.

London emphasized that improving these measures can increase "health span," the period of life spent free from major illness and disability, as well as lifespan. He and other clinicians recommend routine attention to physical activity across adulthood rather than waiting until later life to begin exercise.

Measurement of VO2 max typically requires laboratory testing that quantifies peak oxygen uptake during graded exercise, though clinicians sometimes use field tests or wearable-device estimates as proxies in routine care. Muscle mass and strength can be assessed by clinical measures such as handgrip strength, chair-stand tests and body-composition analysis; these assessments are increasingly used to identify people at risk for sarcopenia and functional decline.

Experts caution that no single metric explains longevity on its own. Genetics, smoking status, diet, socioeconomic factors and access to medical care all influence life expectancy. Still, many researchers and clinicians say cardiorespiratory fitness and muscular strength are practical, actionable indicators that capture the integrated effects of multiple health behaviors.

Public-health advocates have urged clinicians to treat fitness as a routine vital sign and to prescribe physical activity as part of preventive care. For individuals, incremental changes in daily activity, the addition of both aerobic and resistance sessions to weekly routines, and regular assessment by health professionals can provide measurable improvements in both VO2 max and muscle mass.

While research continues to refine how best to quantify and improve these markers across diverse populations, the emphasis on fitness and strength reflects a broader shift in preventive medicine toward preserving function and quality of life as key goals of care.