fisky wrote:
I believe that training for and racing the marathon competitively is bad for your health beginning around age 50 because long/hard training chronically elevates cortisol levels.
About 15 years ago, I went to an anti-aging clinic that compared my blood chemistry to that of a huge data base. The doctor said the good news was that I had the blood chemistry of a person 15 years younger than my actual age of 52. However, I was aging at that point in time at the rate of a 72 year old man! He asked what I was doing because my system was flooded with free radicals.
I told him that I had gone for a very hard 14 mile run the day before. He said that obviously my body had not recovered from the effort.
I stopped marathon training almost immediately. I very seldom do training runs longer than 8 miles any more. I have no major health conditions now, but in my circle of higher level marathoners my age, 4 out of 10 have major illnesses that are linked to inflammation and/or impaired immune system.
To my knowledge, none of my high level sprinter and mid-distance runners my age have any major health issues.
Bottom line: If you want to stay healthy and still run competitively, stick to shorter distances and avoid the half and marathon.
Don't you have to balance the above argument against probable higher risk of injury from tackling the shorter distances? I know I would. Depends what kind of speed work you are doing to support your racing. My greatest fear is major disruption from injury like the hamstring tear I had last summer.