Fitness and Daily Movement May Combine to Lower Heart

How Do Physical Activity and Fitness Affect Heart Disease Risk?

The new BJSM study examined joint, non-linear associations between device-measured physical activity, cardiorespiratory fitness, and cardiovascular disease. Its central message is clinically important: movement and fitness are related but not identical. A person may record daily activity yet still have low aerobic capacity, while another may achieve higher fitness through structured exercise that challenges the heart, lungs, and muscles.

This distinction matters because cardiorespiratory fitness reflects how efficiently the body transports and uses oxygen during exertion. It is influenced by genetics, age, disease, medications, and training history, but it is also modifiable. For prevention, the study supports a practical goal: reduce sedentary time, increase daily movement, and include exercise intense enough to improve fitness over time.

Why Is Cardiorespiratory Fitness a Strong Cardiovascular Marker?

Cardiorespiratory fitness has long been recognized as one of the strongest predictors of cardiovascular and all-cause mortality. Unlike a single risk factor such as blood pressure or cholesterol, fitness reflects multiple body systems working together. Higher fitness is generally associated with better endothelial function, lower inflammation, improved insulin sensitivity, healthier body composition, and more favorable blood pressure regulation.

The American Heart Association has previously argued that cardiorespiratory fitness should be treated as a clinical vital sign when feasible. In practice, that does not mean every patient needs a treadmill stress test. Clinicians can use exercise history, walking tolerance, step tests, or formal cardiopulmonary exercise testing when appropriate, especially for people with symptoms, complex disease, or high cardiovascular risk.

What Should Patients Do With This Research?

The World Health Organization recommends that adults get 150 to 300 minutes of moderate-intensity aerobic activity per week, or 75 to 150 minutes of vigorous-intensity activity, plus muscle-strengthening activity on at least two days weekly. Brisk walking, cycling, swimming, stair climbing, dancing, and structured interval training can all contribute, depending on a person's health status and fitness level.

For people with heart disease, diabetes, severe obesity, long COVID symptoms, chest pain, or unexplained shortness of breath, exercise plans should be individualized with medical guidance. The safest starting point is often modest: shorter walks, fewer prolonged sitting periods, and gradual progression. The broader lesson from the BJSM findings is that prevention is not only about counting minutes; it is about building a body that can tolerate and recover from physical demand.