Any amount and type of exercise is better than none.
There is ample evidence that regular physical activity reduces the risk of death from cardiovascular disease (CVD).
As obesity and related morbidity spiral out of control, participation in athletics and endurance sports has approximately doubled in the last 10 years. In 2012-2013, 7.7 million students participated in high school programs, and in 2014, there was a record number of nearly 42 million American runners and joggers.
Endurance sports draw older athletes, with a record 47% of marathon finishers aged 40 years or over in 2013.
It can end in disaster, however. One study reports a 0.75 fatality rate per 100,000 marathon finishers in the period 2000-2009. These were 28 people, 6 women and 22 men, with a median age of 41.5 years, half of them under 45 years.
Myocardial infarction/atherosclerotic heart disease caused 93% of deaths in those 45 years and older, and the most common cause overall was cardiac arrest.
Exercise does not have to be a marathon
Worrying, maybe, but marathon running is a far cry from federal guidelines recommending that most people should exercise for 150 minutes per week at moderate intensity or vigorously for 75 minutes per week, a target that only half of Americans meet.
A few limited but highly publicized studies have further discouraged would-be participants by suggesting that high volumes of aerobic exercise may be as bad for cardiovascular outcomes as no exercise at all.
In the current report, the American College of Cardiology (ACC) Sports and Exercise Cardiology Council examined recent research on the volume and intensity of aerobic exercise required for favorable cardiovascular health. They also looked at whether there is a threshold of exercise that increases CVD risk.
The Council conclude that small amounts of physical activity, including standing, are associated with a lower risk of CVD; more exercise reduces the risk even further.
Mortality risk in different populations is significantly reduced by moderate and vigorous intensity exercise, even in amounts lower than those recommended by the 2008 Physical Activity Guideline. Higher levels of moderate-intensity exercise reduces CVD mortality.
Is too much exercise risky for the heart?
While these benefits do level out at a certain point, there is no evidence for an upper limit to exercise-induced health benefits.
Any amount of exercise, whether moderate or vigorous, reduces both all-cause and cardiovascular disease mortality risk, compared with no exercise.
The Council believe it is worth investigating the possibility that too much exercise training could be harmful, but research results show that even for very active, life-long endurance athletes, the benefits of exercise training outweigh the risks.
Dr. Michael Scott Emery, co-chair of the ACC Sports and Exercise Cardiology Council, says:
"The public media has embraced the idea that exercise may harm the heart and disseminated this message, thereby diverting attention away from the benefits of exercise as a potent intervention for the primary and secondary prevention of heart disease."
For CVD patients, exercise can save lives, but one study showed that only 62% of heart attack patients were referred to cardiac rehabilitation when discharged from the hospital. Of those, just 23% attended more than one rehab session and only 5.4% completed more than 36 sessions.
Emery hopes that clinicians will be prompted to recommend low and moderate exercise training for most patients.
He also calls for initiatives to promote public health through exercise for all ages, because physical activity modulates behavior from childhood into adulthood.
Dr. Valentin Fuster, PhD, editor-in-chief of JACC comments, "The greatest benefit is to simply exercise, regardless of the intensity, while the danger is twofold: to not exercise at all or to exercise intensely without due preparation."
Medical News Today recently reported that exercise during childhood may lead to healthier gut flora, improving the chances of better brain and metabolic health in the future.