04/05/2026
MUDr. Jan Kovář: ,, Kdo necvičí, umírá 5x častěji než ten kdo cvičí. Sorry for vulgar simplification.
Nízká tělěsná zdatnost strčí do kapsy rizika kouření a diabetu! Náprava nestojí žádné finanční prostředky, jen čas a pochopení! Čert vem veškerou prevenci u praktika se všemi ukazateli a hodnotami, když nebude základní poselství tohle."
Low cardiorespiratory fitness conferred greater all-cause mortality risk than smoking, diabetes, or coronary artery disease in a cohort of 122,007 patients followed for a median of 8.4 years. The mortality difference between low and elite fitness was several times larger than the mortality difference associated with carrying any of those traditional risk factors.
This is the central finding of Mandsager and colleagues, published in JAMA Network Open in 2018. The study analyzed consecutive adult patients referred for symptom-limited exercise treadmill testing at Cleveland Clinic between 1991 and 2014. Cardiorespiratory fitness was quantified by peak estimated metabolic equivalents (METs) achieved during the test. Patients were stratified by age- and sex-matched fitness percentiles into five performance groups: low (below 25th percentile), below average (25th-49th), above average (50th-74th), high (75th-97.6th), and elite (above 97.7th).
Risk-adjusted all-cause mortality was inversely proportional to fitness across the entire range. The mortality benefit of being elite vs high was statistically significant, which the authors describe as "no observed upper limit of benefit." This contradicts a long-standing concern that very high levels of endurance training might carry cardiovascular risk. In this cohort, more fitness was always better, even into the extreme top percentile.
The comparison to traditional risk factors is what makes this study notable. In the same patients, with the same statistical adjustments, the mortality risk increase from being unfit was several times larger than the risk increase from carrying any single major modifiable disease. Fitness is not just one risk factor among many. In this analysis, it was the largest one
A few caveats. This was a retrospective analysis of patients referred for treadmill testing, not a population sample. Patients referred for stress testing typically have symptoms or established risk factors that prompted referral. The cohort is also single-center (Cleveland Clinic). Selection effects may inflate or alter the magnitude of the comparison. The directional finding (low fitness predicts mortality) has been replicated extensively in other cohorts including the Aerobics Center Longitudinal Study and the Cooper Clinic data, but the precise magnitude is specific to this population.
The relative comparison within the cohort is what the study demonstrates most cleanly. In these 122,007 patients, fitness category mattered more for mortality than the categorical risk factors evaluated alongside it.
What this establishes. Cardiorespiratory fitness is one of the most prognostically powerful variables that can be measured non-invasively. The dose-response continues into the elite range. The risk reduction from improving fitness is substantial, and unlike most risk factors, it is improvable through training across the lifespan.
The clinical takeaway from the authors of the paper is direct: cardiorespiratory fitness is a modifiable indicator of long-term mortality, and clinicians should encourage patients to achieve and maintain high levels of fitness.
The practical lever is the same one it always was: structured aerobic training, progressive in intensity and duration, sustained over time. The data argues there is no plateau where you stop benefiting from getting fitter.
Mandsager et al., JAMA Network Open, 2018
