Higher cardiorespiratory fitness is associated with a lower risk of incident venous thromboembolism, with each 1-MET increment associated with an 8% lower VTE risk, and this inverse association was consistently observed regardless of genetic susceptibility.
Each 1-metabolic equivalents increment in cardiorespiratory fitness was associated with an 8% lower risk of incident venous thromboembolism.
High cardiorespiratory fitness was associated with a 27% lower risk of incident VTE compared with low cardiorespiratory fitness.
The inverse association between cardiorespiratory fitness and VTE risk was consistently observed across all genetic risk strata.
Circulating biomarkers related to inflammation, hepatobiliary function, and renal function collectively accounted for approximately 21.5% of the association between cardiorespiratory fitness and VTE risk.
The study included 63,755 UK Biobank participants free of prior VTE, among whom 1,744 incident VTE cases were documented over a median follow-up of 12.5 years.
This research suggests that people with better cardiovascular fitness—the ability of the heart and lungs to supply oxygen to muscles during exercise—have a meaningfully lower risk of developing dangerous blood clots in their veins (a condition called venous thromboembolism, or VTE). The study followed nearly 64,000 adults from the UK Biobank for about 12.5 years, measuring their fitness using an exercise bike test. Those with the highest fitness levels had a 27% lower risk of developing VTE compared to those with the lowest fitness levels, and every incremental improvement in fitness was linked to an 8% reduction in risk. Importantly, this protective effect held true even for people who had a high genetic predisposition to VTE, meaning that being physically fit may help counteract inherited risk. The researchers also found that a portion of this protective effect—about 21.5%—could be explained by biological markers in the blood, specifically those related to inflammation (C-reactive protein), liver function (alkaline phosphatase, gamma-glutamyl transferase), and kidney function (cystatin C and creatinine). This suggests that fitness may reduce VTE risk partly by lowering inflammation and improving organ function, though the majority of the mechanism remains unexplained. This research matters because VTE, which includes deep vein thrombosis and pulmonary embolism, is a leading cause of cardiovascular death and disability. These findings add to growing evidence that physical fitness—which can be improved through regular exercise—may be an important, modifiable factor in reducing VTE risk across a wide range of people, including those with a genetic predisposition to the condition.
Zhou H, Zhang R, Jiang Z, Guo Y, Guo L, Ke H, et al.. (2026). Association between cardiorespiratory fitness and risk of incident venous thromboembolism: a prospective cohort study.. Research and practice in thrombosis and haemostasis. https://doi.org/10.1016/j.rpth.2026.106898