We are involved in youth testing internationally. We want to try to prove without a shadow of a doubt the relationship between physical fitness and health, not just physical fitness and ability to perform.

Since then, I have not missed five consecutive days in getting some type of aerobic exercise, mostly jogging.

After 26 years, I am still practicing what I preach.

Now I say that if you run more than 15 miles a week, it's for something other than aerobic fitness. Once you pass 15 miles, you do not see much further improvement.

I used to think that it didn't make any difference how far you ran if you had a good, strong musculoskeletal system and no underlying cardiovascular problems.

Exercise is a journey, not a destination. It must be continued for the rest of your life. We do not stop exercising because we grow old - we grow old because we stop exercising.

Aerobic dancing is already adjusting to injury problems and will probably phase out to some extent.