It is common wisdom that exercise is healthy. A few of the benefits of exercise include: reduced cardiovascular risk, reduced diabetes risk, prevention of several types of cancer, improved mood, and reduced risk of Alzheimer’s disease.
But, how much exercise at what intensity is most helpful? Simple, clear guidance on the benefits of exercise is difficult to find.
When assessing a patient’s cardiovascular risk, I like to use a global risk assessment calculator that factors in age, gender, cholesterol ratio, blood pressure, smoking status, and diabetes status. My favorite cardiovascular global risk assessment tool can determine the benefits of various treatments (including exercise, Mediterranean diet, or statin therapy) on cardiovascular risk. Unfortunately, in this calculator (which is better than any other I have seen) the effect of physical activity is absolute – “physical activity” reduces cardiovascular by about the same amount as statin therapy. But it can’t be this simplistic; physical activity once a week must be less effective than daily physical activity; running for an hour must have a different benefit than walking for an hour.
To help clarify the benefit of exercise on physical health, I asked my research assistant, Dakota, to summarize a recent systematic review on physical activity and mortality. He summarized the research like this:
- People of all ages who are able to be physically active will have a reduced mortality rate of 14 to 26% by doing 150 to 300 min of moderate to vigorous physical activity a week, respectively.
- Doing a certain amount of physical activity a week does not guarantee a longer life and does not reduce the negative affects of smoking or an unhealthy diet.
- Studies show that the more vigorous the activity the more beneficial it is to the body.
- Studies also show the more time spent doing physical activity per week the better as long as a healthy diet is maintained and nutrients are not depleted.
- Physical activity is shown to reduce mortality substantially more in women than men.
- As a strict relation of risk reduction per calories burned the results were greater than or equal to 10% risk reduction for 1500kcal/week in men and 650kcal/week in women. Studies support the message that ‘some is good, more is better.’
So, to reduce mortality by about 26%, exercise for 300 minutes per week. Men should burn about 3,750 calories per week and women about 1,600 calories per week. My favorite way to assess calories burned is to use the Runmeter app on my iPhone – it can be used for walking, biking, hiking, or running. Just enter your weight into the app and it will calculate calories burned and help you keep track of your own benefits of exercise!
Richard Malik, ND
Naturopathic Medicine in Connecticut, Naturopathic Medicine in Vermont, Naturopathic Oncology in Vermont, Naturopathic Oncology in Connecticut