In order to lose weight a person should reduce their calories and increase the amount of exercise that they do.  After all, the reason that we Americans are fat is because we eat too much and exercise too little.  Right?  Wrong.  In previous posts I have discussed the myth of calories and calorie reduction.  Today I want to address the myth that exercise is required to lose weight. Before you start to send me e-mail, please allow me to state my position.  I am a firm believer in being active.  This includes regular exercise.  There are numerous benefits to exercise.  Better over-all health, reduced body fat, better mood, better cognitive skills, better sleep, better self image, increased confidence and damn it makes you look good naked.  But as far as exercise being required for weight loss, it isn’t.

The idea that exercise is required to lose weight is actually fairly new.  Back in the 1960’s doctors advised against exercise for weight loss. Today it is considered essential.  The Center for Disease Control (CDC) now recommends 150 minutes of exercise a week for adults and an hour a day for children.  That’s a complete course reversal in fifty years. Where has exercise gotten us?  Let’s look at the numbers. First, let’s look at obesity rates.  Since 1980 the obesity rates for adults have doubled and the obesity rates for children have tripled.  Next, let’s look at the number of people who exercise.  In 1991, 20 million people belonged to 14,000 health clubs.  In 2006, 42 million people belonged to 28,000 health clubs.  The number of people under the age of 18 that joined health clubs doubled from 1987-2002.  So to make sense of this, the number of people who joined health clubs doubled, the number of health clubs also doubled, but so did the adult obesity rate.  The number of children who joined health clubs doubled, but their obesity rate tripled.  Something must be missing, because the numbers just don’t make sense.

People tell me all the time that when they used to exercise they lost weight and when they stopped they gained it back.  They credit the exercise for their weight loss. That is understandable.  Exercising is hard.  You would like to think that since you did all of that hard work that your reward was the weight loss.  I always ask if they found that when they were exercising that they paid more attention to what they were eating and drinking.  The answer is always, yes. I try to gently (I must admit, and my editor reminds me, that I’m not too good at being gentle) suggest that maybe it was the awareness of their diet that led to the weight loss and not the exercise.

But, most people insist that it was the exercise. They tell me how it helped them lose weight and increased the rate of their metabolism.  It’s feels good to believe that, but unfortunately it just isn’t completely true.

In 2007 the American Heart Association and American College of Sports Medicine published joint for physical activity and health.  They suggest that 30 minutes of physical activity 5 days a week is required to “promote and maintain health”, but they never say that more will have any benefit beyond “maintaining health”.  They continue, “Few reliable data are available on the relative contributions to this obesity epidemic by energy intake and energy expenditure”.  So there isn’t any data suggesting that exercising more and eating fewer calories will promote weight loss. “While more information is gathered on the varied (my emphasis) causes of obesity, it seems vitally important for public health efforts to address both energy expenditure and energy intake”. “It is reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight over time, compared with those who have low energy expenditures.  So far, data to support this hypothesis are not particularly compelling”. Wow!  They are going to stick with and continue to promote the status quo of “eat less and exercise more” even though there is still no scientific evidence to back it up.  What a disservice to the American public.


So what would happen if you took four groups of women and gave each group a daily exercise requirement such as what the CDC recommends?  How much weight would they lose in 24 weeks?  Well, that’s what Timothy Church wanted to know when he and his colleges ran this They took four groups of women and assigned three of them a daily exercise regimen.  The groups were assigned a set amount of time to exercise and were instructed to make no dietary changes.  One group was not to exercise at all.  The other three were to exercise 72, 136 and 194 minutes per week respectively.  In each group some lost weight.  Some gained weight.  And some stayed the same.  As a group, the non-exercisers lost 2 pounds in 6 months.  Out of the three exercise groups the most weight lost came from the group doing 136 minutes a week of exercise. They lost on average 4.6 pounds.  That’s 54 hours (136 minutes x 24 weeks) of exercise to lose 2.6 pounds more than the group that did nothing.  But more exercise has to be better, right?  The group that exercised 194 minutes a week, 77 hours in six months, lost only 3.3 pounds.  Only 1.3 pounds more than the group that did nothing at all.  Not much of a weight loss reward for all of that work.  In a 16 month University of Nebraskastudywomen aged 17-35 who exercised had no significant weight loss.  The authors’ state, “Although it is common to expect weight loss in response to exercise, our group, and others, showed no significant decrease for weight in women”.

By Haadi