You have to run 75 to 100 miles a week if you expect to break the four-minute mile.

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

According to the Gallup Poll, 24 percent of American adults exercised regularly in 1961, and 50 percent after 1968. The peak was 59 percent in 1984, dropping off to 51 percent last September.

I don't criticize weight training - as long as it is not a substitute for aerobic training.

There are six components of wellness: proper weight and diet, proper exercise, breaking the smoking habit, control of alcohol, stress management and periodic exams.

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.