Friday, June 6, 2014

Exercise for Weight Loss - Clear Your Calendars

Recently, I was looking for articles on how exercise effects weight loss (or not) and finally found one on PubMed that actually controlled for diet and different levels of calorie exertion over a fairly long time period.  I wanted to share with you the trial, the researcher's take-aways and what the results really state.

Aerobic exercise alone results in clinically significant weight loss for men and women: Midwest Exercise Trial-2

Researcher summary

EEEx at 400 or 600 kcal/session resulted in a significant reduction in weight compared to controls.

My summary

1)200 kcal difference over 10 months resulted in a 0.4 pound weight loss difference. That is zero point four. Think about it. Nearly 43,000 (thousand) additional calories supposedly "burned".

2)For 600kcal group, individuals had to burn approximately 12,772 calories to lose one pound, which is the equivalent of exercising 21 days to "burn off" a pound.

3)For the 400kcal group, individuals had to burn 8,866 calories to lose one pound.

4)Compliance in the program, even when compensated was only around 67%

5)If the data trend continued (which I doubt it would), if you'd like to lose an additional 2 pounds, you'd have to be in a new research group that exercises 5 days a week for 10 months, with a 1,600kcal/day expenditure. That's akin to running (approximately) 15 miles a day. Keep in mind, these are obese or overweight patients.

For those 2 pounds, that is 3,225 miles, or a leisurely RUN from Miami, Florida to Seattle, Washington.  Google estimates that would take a 'few' hours (I don't think Google uses running estimates though):

6)A few interesting tidbits:

600kcal women (n=18) - 17% gained weight.
400kcal women (n=19) - 26% gained weight.

600kcal men (n=19) - 21% gained weight.
400kcal men (18) - 28% gained weight

It seems for a large portion of the individuals in the study, even those with relatively high continuous energy expenditures gained weight, though the impact was lessened a bit with added exercise.

The researcher's conclusions: "400 or 600 kcal/session resulted in a significant reduction in weight compared to controls...Absence of a significant increase in weight loss between the 400 and 600 kcal/session groups suggests compensation in components of energy balance and warrants additional investigation that could lead to targeted interventions" - ahh like, increasing exercise does squat because your body is under duress and adjusts accordingly?

Important item the study doesn't cover:

Followup > exercise regime stopped. What happened to patient weights?