Why do so many athletes go into cardiac arrest during exercise?

I thought working out was good....

Working out IS good. It is athletes that have undiagnosed heart problems, usually from birth, that have sudden heart attacks while the heart is under extra stress like exercise. Also those who are using drugs that make your heart rate go up.

Long-term benefits of exercise outweigh the risks so much that working out is a no-brainer. However, any time you put stress on your heart there is a chance it will fail.

so because some athletes get heart attack when they exercise, u now think that working out isnt good?

many people push themselves too hard. if you have a heart problem, and go too far, then you might actually go into cardiac arrest.

They already have an unknown heart problem,but when you get to the college or pro level there is a good chance they are on performance enhancing drugs.

sometimes athletes just don't know when to quit, and they cause too much strain on the heart. exercise IS good. but like everything... all things in moderation is better. you should listen to your body, some athletes push and DON'T listen to their bodies. Some people become fanatics about fitness. i have heard of non athletes who didn't do any exercise or very little apart from everyday activities live to be 100 +. Yet, so called healthy athletes dying young? doesn't that tell you something.

"So many?"

Numbers please. I've never heard that, nor have I gone into cardiac arrest myself.

There have been a very few high profile ball sport jocks, but the one's I'm aware of all were fooling with drugs or had a previously undiagnosed heart defect.

This compared to the thousands upon thousands of couch potatos who expire daily from self-inflicted heart disease.

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Edit: I should note that most football, basketball, and baseball players are complete morons when it comes to health, nutrition, hydration, and exercise physiology.

Any above average amatuer triathlete or marathoner knows more on the subject than most of the alleged "pros"

In fact, I don't even consider baseball players to be athletes.

cardio is better for the heart than lifting weights(lifting weights and cardio go hand and hand) since it speeds up you're metabolism and increases you're heart rate. :)!