We covered the subject of hormesis and the dangers of radiation in another article, showing that even low levels of radiation cause harm and increased (not decreased) cancer rates.

Radon Dangers; Hormesis Explored; via A Green Road Blog http://agreenroad.blogspot.com/2012/04/radon-dangers-and-hormesis.html


Now we tackle the hormesis theory in the arena of hard exercise.

Pushing too hard during exercise results in catabolism, which is a condition where body cells die, due to lack of oxygen. If your body has to exist for very long without oxygen, that is not a good thing. Try stopping your breathing for thirty minutes, or even for two minutes. The body does not like to live without oxygen and will not allow you to stop breathing, at least not until your time is up. Exercise is ok, but stay out of the catabolic zone where your tissues are operating without oxygen.

Exercising too hard also creates excessive amounts of stress hormones, which leads to diseases of all kinds.  Excess stress is not good for the human body. It makes sense to prevent injury, inflammation and potentially all kinds of diseases by not pushing too hard during exercise, or by not running marathons. 

Pushing so hard that muscles tear is not good for the body. Tearing muscle tissues creates injuries and increased risk of more injuries in the future, as the part of the body that is torn repeatedly weakens over time.

Exercising too hard also creates a weakened immune system and insomnia. Exercising too hard creates insomnia which then results in other negative things happening in the body over the long term. 

But all of these things are nothing compared to what happens to the heart when a person exercises too hard. Marathon runners are supposed to be the healthiest people on Earth, but they suffer from heart scarring due to excessive exercise and tearing of muscle tissues. 

Multiple studies show the negative effects of marathon type running and/or over exercising. Over exercising may cause:

1. Increased levels of inflammation that may trigger all kinds of heart problems. In a group of long time marathon runners, 50% of them had heart scarring.

2. “Diffuse scarring and some structural changes, similar to the changes seen in the human endurance athletes.” (animal studies)

Source: http://fitness.mercola.com/sites/fitness/archive/2012/06/01/long-cardio-workout-dangers.aspx?e_cid=20120601_DNL_art_1