Is too much of exercise bad for you?

Is too much of exercise bad for you?

അമിതമായ വ്യായാമം ദോഷകരമാണോ?

It is well known that regular exercise is good for the heart. Almost all national guidelines recommend 150 minutes a week of moderate intensity physical activity. But like the old saying that too much of good things can be harmful, is too much exercise bad for you?

The Copenhagen City Heart Study assessed the amount of jogging and long term mortality.
In the introduction of their article, they mentioned the historical anecdote of sudden death of Pheidippides, a professional running courier in 490 BC. It is believed that he ran from Marathon to Athens, Greece, approximately 25 miles to give the news of victory of Athens overs Persia. He exclaimed “Nike’” (victory), collapsed and died. But they also quote another version of this story which says that Pheidippides continued to run from Athens to Sparta for military help. He is supposed to have run the distance from Athens to Sparta of 137 miles in 48 hours!

About 1100 healthy joggers and nearly 4000 healthy non joggers were studied as part of the Copenhagen City Heart Study since 2001. The study showed that 1 to 2.4 hours of jogging per week was associated with lowest mortality. They noted that the optimal frequency of jogging was 2 to 3 times per week and optimal pace was slow or average. When they divided joggers into light, moderate and strenuous, lowest risk for mortality was found in light joggers followed by moderate joggers and strenuous joggers. Light and moderate joggers had lower mortality than sedentary non joggers. But mortality rate of strenuous joggers was not significantly different from that of the sedentary group.

Million Women Study was started in 1998 with about 1.1 million women without prior disease of heart or blood vessels. Compared to inactive women, those reporting moderate activity had significantly lower risk of heart attack, stroke and clots in veins. But women reporting strenuous physical activity every day had higher risks of all the three than those doing such activity 2 or 3 times per week.

One of the earliest studies to report a similar relationship between intensity of exercise and mortality was among college alumni. That study evaluated nearly 17,000 Harvard alumni, aged between 35 to 74 years
Death rate was found to decline steadily as energy spent on activity increased from 500 to 3500 Kilocalories per week. But beyond that, it increased slightly, again indicating a so called U-curve or reverse J-curve.
Death rates were one quarter to one third lower among alumni spending 2000 or more Kilocalories during exercise per week than among less active men.

It should be noted that all these studies have uniformly documented the long term benefits of exercise.
Regular exercise programs tailored to each individual’s physical capacity is highly essential for good health and mortality benefits. The question is only regarding extremely strenuous and prolonged exercise.