Wayne L. Westcott: Knowing how often to exercise

Wayne L. Westcott

Exercise frequency is a very interesting topic because there are many types of exercise and therefore many research-based training recommendations.

Let’s start with strength training for beginning exercisers. This summer, we published our eight-year study on strength training frequency in The Physician and Sports Medicine, a medical research journal. Our 1,725 beginning exercisers performed identical strength training workouts one, two or three days a week for a period of 10 weeks. Concerning muscle gain, those who trained once a week added 0.7 pounds of muscle, those who trained twice a week added 3.1 pounds of muscle, and those who trained three times a week also added 3.1 pounds of muscle. This result revealed equal increases in muscle tissue from two or three weekly strength training sessions.

With respect to fat loss, the one day per week group lost 1.1 pounds of fat, the two day per week group lost 3.2 pounds of fat, and the three day per week group lost 4.4 pounds of fat. This indicated that more frequent exercise sessions resulted in greater fat loss.

It could therefore be concluded that three day per week strength training may produce better overall body composition changes (muscle gain plus fat loss), than less frequent exercise sessions. However, such is not the case for more advanced strength training participants.

A recent study with previously trained young men showed that relatively hard strength training sessions required at least 72 hours recovery time before muscle strength returned or exceeded the initial strength level. Because every other day strength training does not permit full muscle recovery and rebuilding, it is not advisable for advanced trainers to exercise three days a week.

Two total-body workouts per week are significantly more productive for advanced strength trainers than more frequent exercise sessions. This does not mean that seasoned strength trainers cannot perform some resistance exercises every day, but they should not work the same muscle groups more than twice a week. For example, they could effectively perform upper body exercises on Mondays and Thursdays, and leg and midsection exercises on Tuesdays and Fridays.

Whereas strength training produces a moderate degree of muscle micro-trauma, aerobic activity is considerably less disruptive to muscle tissue. Consequently, standard endurance exercise may be performed on a daily basis. This would include aerobic activities such as walking, running, cycling, stepping, rowing and swimming, performed at about 75 percent of maximum heart rate or approximately three-quarters of maximum effort.

Really hard endurance activity is another story. When I was as assistant track coach at Penn State University, we had four runners who were national champions in distance events. However, even these elite athletes could not do two really hard training sessions in a row, with the exception of the American record holder in the 10,000-meter run.

If you perform hard endurance workouts, you may train on a daily basis, but be sure to alternate hard and easy exercise sessions. In my experience, advanced aerobic athletes achieve higher performance levels when they limit really hard training sessions to twice a week, and perform lighter workouts on the other days.

If you like to combine strength and endurance exercise, you might consider performing strength training two days a week, harder endurance training two days a week, and easier endurance training two days a week, with one rest day to enhance overall recovery and restore performance potential.

Wayne L. Westcott, Ph.D., teaches exercise science at Massachusetts' Quincy College and provides fitness consultation for the South Shore YMCA. He has authored 24 books on strength training.