The Heart Muscle

Quoted post said:

Originally posted by tomUK
Not sure if there are any MDs who read this board, however, would anyone know if it is possible to over-stress the heart?

While I am not an MD, I do know that overexertion can cause hypoglycemia. This is where the body's glycemic stores are emptied for fuel(instead of the fat stores). Diabetics commonly encounter this, and counter it by simply eating something. If you are dizzy, confused, tired, or shaking for no reason, that is a sign that this has happened. I'm not sure if repeated overload will lead to anything permanent, or if over-stress leads to anything more serious (heart attack). Hope this helps.

from my knowledge it seems that the body will normally refuse to cooperate before the heart becomes ischaemic (in a healthy individual). Obviously if the heart is not receiving its share of the oxygen then it cant pump blood (oxygen) to other parts of the body and therefore they wont work either. There are cases though when the body is pre stressed with an illness, Influenza for example, where the heart has had a large enough ischaemia to go past the point of no return with the result being death. (Tom Simpson is an example though it seems drugs rather than illness were his stressor).

In general, i think you would struggle to push yourself hard enough to "over-stress" the heart unless you were sick or under the influence of drugs/medication.

Quoted post said:

Originally posted by tomUK
Not sure if there are any MDs who read this board, however, would anyone know if it is possible to over-stress the heart?

I also am not an MD. However I did take some formal medical university training prior to following a different career path.

My opinion is that your question may be too general. The general answer is simply "yes". Over-stress can cause a heart attack. But I think we all know that.

However regular cardio exercise is meant to raise your body's threshold to over-stress. Muscles need oxygen so it's imperative your heart is properly supplied. Through regular exercise, not only does your heart get stronger, your veins/vessels permanently dilate to increase blood flow. As you lose body fat your heart has less distance to pump blood before returning to the heart.

So, it's important people don't get scared of exercise thinking it will cause a heart attack when really, if done sensibly at minimum of three times per week, it can be used to help prevent one.