21.   Cohan said that he was influenced about the benefits of vigorous exercise by a New York study that found a correlation between survival rates and lean body mass.

22.   Demanding physical activities like vigorous exercise and sexual activity activate the sympathetic nervous system.

23.   Doctors in ancient times believed that vigorous exercise was harmful.

24.   For people who are used to vigorous exercise, a spinning class can be an aerobic workout, but not a real physical challenge.

25.   Further studies are needed to determine whether less vigorous exercise produces the same effect.

26.   Gradually work up to equal intervals of slow and vigorous exercise, Westcott suggests.

27.   He maintained a vigorous exercise routine, walking eight miles a day and playing a daily round of golf.

28.   He prescribed as a preventive a healthy life-style founded on vigorous exercise, sleep on a hard wooden bed and a diet that shunned meats and emphasized grains.

29.   If Tools does not run into complications, his doctors say, he should eventually be able to walk long distances and do most things except vigorous exercise.

30.   If we hope to live longer, we must engage in vigorous physical exercise.