Interesting article in today's Toronto Star (thestar.com)
Seems as if marathon participation and training won't prevent coronary arterial disease. Not only that but repeated exercise for more than two hours at a time is bad for our bodies. The solution? No more than 1.5 hours of strenuous exercise at a time. Interval training is good however.... And strength training ... And avoid the 'five food felons'
Th article is just one opinion but it's worth noting.