Muscle wasting loss begins as early as age 25. From age 25-50 the rate of muscle loss is up to 0.5 pound/year. From age 50-late 60s the loss accelerates at up to one pound/year. After that it goes as high as 2 pounds per year to your early to mid
eighties. If you are lucky enough to make it to your mid 80s, muscle loss goes up to four pounds per year. Increase is not
linear but exponential loss.
Dr. Tucker’s comment on these stats: The purpose of exercise is to improve your functional capability and allow you to maintain your activities of daily living. I don’t think exercise is just to burn calories. When I teach clients how to exercise it is to maintain flexibility, strength and endurance. Calories will take care of themselves if you eat right, the best example being a Paleo diet or Mediteranian diet.
See my exercise article at http://www.toyourhealth.com/mpacms/tyh/article.php?id=1277