Is Less Exercise More?Monday, March 11, 2013
This weekend, at my presentation in Grande Prairie, I told the packed audience that trying to increase your levels of physical activity (beyond the little that is needed to be moderately fit) may be counterproductive, especially if you are carrying around a significant amount of weight.
Now, a study by Gary Hunter and colleagues from the University of Birmingham, Alabama, published in the Medicine and Science in Sports and Exercise, shows that in older women, working out nearly every day actually reduces total energy expenditure, while providing virtually no additional metabolic benefit.
The researchers randomly assigned 72 women (60-74 years old) to 16 weeks of: 1 day/week of aerobic and 1 day/week of resistance (1+1); 2 days/week of aerobic and 2 days/week resistance (2+2); or 3 days/week aerobic and 3 days/week resistance (3+3). (Aerobic training consisted of 40 minutes of aerobic exercise at 80% maximum heart rate and resistance training consisted of 2 sets of 10 repetitions for 10 different exercises at 80% of one repetition maximum.)
Wile all groups (equally!) increased fat free mass, strength and aerobic fitness, both total energy expenditure (TEE) and activity energy expenditure (AEE) increased with the 2+2 group but not with the other two groups.
As for non-exercise AEE (NEAT), while it increased significantly in the 2+2 group (+200 kcal/day) and showed a trend for an increase in the 1+1 (+68 kcal/day) group, it significantly decreased(!) in the 3+3 group (-150 kcal/day).
Thus, the authors conclude that almost daily 3+3 training may in fact have less beneficial effects on energy balance than 1+1 and 2+2 training.
Assuming that the same holds true for younger individuals (and both men and women), this may mean that getting our patients to exercise just 4 times a week (or perhaps even just twice), may not only be enough but in fact better than dragging themselves to the gym everyday.
In the end, however, I stand by my conviction that the main role of including regular physical activity into your weight management program is to ruin your appetite rather than to burn calories.
Hunter GR, Bickel CS, Fisher G, Neumeier W, & McCarthy J (2013). Combined Aerobic/Strength Training and Energy Expenditure in Older Women. Medicine and science in sports and exercise PMID: 23377831