Comment on

• Physical fitness as a predictor of mortality among healthy, middle-aged Norwegian men.

  Sandvik L, Erikssen J, Thaulow E, Erikssen G, Mundal R, Rodahl K. Sandvik L, et al. N Engl J Med. 1993 Feb 25;328(8):533-7. doi: 10.1056/NEJM199302253280803. N Engl J Med. 1993. PMID: 8426620
• The association of changes in physical-activity level and other lifestyle characteristics with mortality among men.

  Paffenbarger RS Jr, Hyde RT, Wing AL, Lee IM, Jung DL, Kampert JB. Paffenbarger RS Jr, et al. N Engl J Med. 1993 Feb 25;328(8):538-45. doi: 10.1056/NEJM199302253280804. N Engl J Med. 1993. PMID: 8426621