12% of mortality in the US from all causes is due to physical inactivity. One of the major causes of death in the US is cardiovascular disease. Adults who are more active are 30-40% less likely to develop cardiovascular disease than inactive adults.
A regular exercise routine can decrease blood pressure by 5 to 15 points in as little as a month. Furthermore, those who exercise are likely to have cholesterol levels that are lower in unhealthy cholesterol and higher in the healthy cholesterol. They are less likely to develop type II diabetes, which is a health risk in itself but also a contributor to heart disease. They have lower levels of inflammation, which provides stress on the heart.
The reduction of heart disease risk incurred with additional exercise is on par with the reduction of death from quitting smoking, avoiding obesity, and getting high blood pressure under control. The good news is that adding exercise is a change that everyone can make, regardless of genetics, financial ability, or access to health care services.
Individuals who think that they are exercising at a “moderate” or “hard” rate of exertion receive more health benefits than those who exercise at a lower intensity, regardless of whether or not they are actually exercising at an intensity and duration consistent with current disease reduction recommendations. This is good news for runners, since that is of a higher intensity level than other activities such as walking. In one study, runners who ran for any length of time, including less than 51 minutes per week, had lower mortality rates than non-runners.
The reduction in disease risk applies even to individuals who were sedentary for much of life. Once an individual becomes active, they reduce their risk of heart disease more than those who remain active.
Even patients who already have cardiovascular disease can benefit from exercise. Those with light to moderate exercise have the lowest disease risk. Experts recommend that unless they have certain risk factors that make exercise contraindicated, those with cardiovascular disease should exercise for half an hour to an hour five to seven days a week.
For general fitness and disease reduction, the CDC recommends moderate exercise 150 mintues per week (5 times for 30 minutes) or vigorous exercise 75 minutes per week (3 times for 25 minutes), with the addition of two weekly strength training sessions. More can be better, however. In one study, each additional 10 miles run per week reduced body fat and triglyceride levels and increased HDL (healthy cholesterol) up to 40-50 miles per week, and those who ran greater than 40 miles a week had a thirty percent lower chance of developing heart disease in the next 10 years than those who ran less than 10 miles per week.
Douglas, Cannon, & Downey. (2015). “Exercise and fitness in the prevention of cardiovascular disease.” UptoDate.