This study looked at how effective regular physical exercise is in reducing mortality caused by cardiovascular disease and mortality in general. 

It is widely accepted that increasing physical activity is good for health, particularly for the heart. Physical activity helps to manage weight and reduce the risk of developing conditions that may put strain on the heart such as high blood pressure and cardiovascular disease.  Cardiovascular disease, such as coronary artery disease, where blood vessels become narrowed due to high blood pressure or a build up fatty deposits can lead to a heart attack, arrhythmias (irregular heartbeat), heart failure and stroke. Exercise also reduces the risk of developing diabetes.

The current study investigated the effect of exercise by looking at different intensities of energy expenditure of walkers and runners to evaluate the specific benefits to prolonging life.

This study was conducted on 8,436 males and 33,586 females, with ages ranging from 36 to 77 years at the beginning of the study. Energy expenditure was calculated in metabolic equivalents or METs, where 1 MET is the level of energy typically used per hour for walking or running. METs are a reliable way of measuring exercise intensity in a way that is not seen by calculating duration of exercise alone. Participants were divided into four exercise categories:

• Category 1: <1.07 MET-hours/day
• Category 2: 1.07 to 1.8 MET-hours/day
• Category 3: 1.8 to 3.6 MET-hours/day
• Category 4: >3.6 MET-hours/day

The study ran for an average of 9.6 years and the risk of death was compared between category 1 and the rest of the categories. The study found that when compared to category 1, overall general mortality was 11.2% lower in category 2, 32.4% lower in category 3 and 32.9% lower in category 4.

Mortality due to overall cardiovascular disease was 23.6% lower in category 2, 35.2% lower in category 3, and 34.9% lower in category 4 compared to category 1.

Mortality due to diabetes was 39.4% lower in category 2, 63.8% lower in category 3 and 90.6% lower in category 4 in comparison to category 1. Similar trends were seen in mortalities caused by heart failure, high blood pressure, arrhythmias, and cerebrovascular disease (poor blood supply to the brain).  

Regular physical exercise, like taking daily walks, has substantial health benefits in prolonging life. 

The study counted mortalities based on the National Death Index and therefore some participants who may have died may be misclassified as alive. 

Discuss with your doctor or health fitness instructor ways you can increase your daily physical activity and calculate your daily MET scores.