We know how important exercise is in improving our health and preventing disease, especially heart disease. Is there an optimal frequency of exercise in older women?
A recent randomized study looked at the effects of three different combined aerobic and resistance training programs on total energy expenditure and activity related energy expenditure in 60-74 age range sedentary women.
These women were randomized to weekly schedules of 1 day of aerobic and 1 day of resistance training, 2 days of each, or 3 days of areobic and 3 days of rsisitance training. Aerobic training included 40 minutes on a treadmill or cycle ergometer at 80% max heart rate. Resistance training involved 2 sets of 10 repetitions of 10 different exercises.
At 16 weeks, aerobic fitness, strength, and fat-free mass improved similarly in all groups, but the total and activity-related energy expenditure increased significantly (by 300kcal daily) only in the group that exercised 4X per week. (2 days aerobic and 2 days resistance training). Women who exercised 6X per week experienced a decrease in activity-related energy expenditure not related to their exercise training.
In other words, the women that exercised more were following such a ridgid schedule of exercise 6X per week, that they were less inclined to do physical activites in their free time.
The bottom line: Aerobic exercise and resistant exercise together twice a week is equally as effective as more frequent exercise. Leave some room for fun!
Reference: Hunter, GR et al. “Combined aerobic and strength training and energy expenditure in older women”. Med Sci Sports Exerc 2013 July; 45:1386.