Exercise: Are there bad side effects?
Dr. Lubdub, if I want to prevent a heart attack, what should my New Year’s resolution be for exercise?
Resolve to be active! One study has shown that people who sit for less than 30 minutes at a time live longer. People who do vigorous exercise regularly may live 6 years longer than people who don’t — show me a medicine that can do that.
Six years! That’s an impressive “medication.” Should my resolution be to exercise daily?
Daily moderate physical activities like walking should be done daily. However, vigorous exercise probably should not be done daily. In fact, one study showed that women who do daily, vigorous exercise are at higher risk of heart attacks, strokes and blood clots compared to those who did not exercise daily.
Yes! I’m vindicated. I knew exercise was bad for you because it HURTS! Tell me the other bad side effects of exercise?
Think of exercise like medicine: small doses won’t help, and too large of a dose can hurt. Overuse injuries and joint damage occur from prolonged, high impact exercise. Heart rhythm problems such as atrial fibrillation are seen in people who do endurance type exercise more than 4 days a week. Scar tissue in the heart is seen in long distance runners. Higher amounts of coronary artery disease are seen in marathon runners compared with those who don’t run at all. Lastly, time spent on excessive exercise often comes at the expense of time with spouse and children.
Wait — so you’re telling me if I exercise, I can live 6 years longer but suffer from shin splints, atrial fibrillation, heart disease, and loneliness? I’m never putting on running shoes again!
Don’t get me wrong. The real questions we should be asking are: What’s the right dose of exercise to prevent heart attacks? What’s the amount of exercise after which there is no real added benefit?
I was thinking the real question was: Does pushing my luck, jumping to conclusions, and running away from responsibility count for exercise? Actually, before you go on, give me some idea about what is moderate and vigorous activity?
Moderate exercise includes: walking 3mph, bicycling <10mph, water aerobics, doubles tennis, ballroom dancing and gardening.
Vigorous exercise includes: uphill walking or speed walking, bicycling >10mph, jogging, singles tennis, aerobic dancing, or heavy gardening.
One rule of thumb is that vigorous exercise is any activity in which you can’t speak a full sentence without needing to take a breath.
Hah….I’d probably not make it through a three word sentence with slow walking. So Dr. Lughead, let’s get back to the question: at what point is the benefit of exercise lost?
In a study from the 3rd happiest country on earth, the best dose of jogging was 2 hours total per week, a frequency of 3 times per week, and running at an average pace. In this study, less benefit was seen in joggers who exercised more than 2.4 hours/week, ran at a fast pace, and jogged more than 3 times per week. In the Million Women study, women who exercised more than 3 times/week were more likely to have strokes and blood clots in the legs compared with people who exercised less.
Seriously! How can too much of a good thing like exercise be bad?
I agree that these observations definitely get our attention. In another large study over 15 years, the “sweet spot” for exercise was 3 times/week, running at a pace of 10 minute miles, for a total of 6 miles per week. They found that people who ran more than 20 miles week, 6 or more days a week, at a 7.5 minute mile pace, had worse outcomes.
I’m stunned. I’ve always thought that I need to exercise a lot to be “healthy.” But what if I’ve had a heart attack – is more exercise better?
One study showed that heart attack survivors who ran more than 30 miles/week, were more likely to die from heart disease. The benefit to exercise occurred at distances below 30 miles/week. Another study showed that daily exercise in heart attack survivors was more likely to lead to higher death rates.
Eeeesh! So should I stop running marathons?
At this point, there’s a signal that “excessive exercise” may be harmful, but nothing is really proven. However, I do joke with my patients that you only get so many heart beats, so why would you waste them on exercise? Actually, my real opinion is that I’d rather see bumper stickers that read 2.62, instead of 26.2. I think at a minimum we’d prevent a lot of joint problems.
Summarize it for me Doc!
If you want the right dose of exercise to live longer:
1). Do NOT sit for more than 30 minutes at a time
2). Do moderate physical activity throughout the day
3). Do NOT do daily, vigorous activity
4). Do exercise vigorously 3 times week for 30-40 minutes at a time
Oh, and enjoy the video about the dangers of excessive exercise . . .