Here’s the second episode of the BBC documentary series The Men Who Made Us Thin. This episode deals with exercise and drugs as failed methods for treating obesity.
The first half takes us down memory lane to revisit the fitness craze that sparked jam-packed health clubs, aerobics classes, and of course Jane Fonda’s workout videos. As the researchers who are interviewed explain, the belief that aerobic exercise induces weight loss is certainly entrenched, but was based on bad science — which is why even today, health clubs are packed every January and half-empty by May. People put in the time and effort, don’t lose weight, become frustrated and give up.
Now, there’s nothing wrong with exercise itself. Exercise (the right kind) is great for overall health, endurance, mood, etc. Part of our Sunday routine is to go to the recreation center, where Chareva and I take turns lifting weights while the girls swim. I’m delighted that as I near age 55, I’m stronger than I was at 35. I feel good when we leave the gym. Chareva was delighted recently when she was checking out at a hardware store and the clerk looked at her arms and asked, “Do you lift?”
But the notion (heavily promoted by the fitness industry) that walking on a treadmill or dancing around the aerobics room a few times per week is going to lead to significant weight loss simply isn’t true. I believed it was true for years and had a difficult time letting go of the idea … perhaps because exercise = weight loss just feels cosmically correct: if you put out that much effort, you should be rewarded with the weight loss you desire.
Unfortunately, the research shows otherwise. Here are just a few examples:
In this study, women participated in aerobics and resistance exercise sessions five times per week for 24 weeks. That’s a lot of exercise. The result? On average, the women lost 2.2% of their body mass and 10% of their fat mass. A 10% loss of fat mass may sound impressive at first, but let’s do some simple math. If a woman is at 35% bodyfat (obese) and weighs 175 pounds, that’s 61 pounds of fat. So the reward for 24 weeks of exercising five times per week is … dropping six pounds of fat. Whoopee. Clean up your diet, and you could lose that much fat in a few weeks.
This study supports a point one of the researchers made in the film: Kids don’t get fat because they don’t move around as much as their lean peers. They get fat first, then stop moving as much. (That’s why I cut the walking-to-school bits from the Director’s Cut of Fat Head. It was after the original release that I learned I got in wrong in that section.)
This article about a meta-analysis of studies on kids and exercise makes the same point, only in reverse: getting fat kids to move around more doesn’t make them thinner:
Researchers analyzed results from 14 earlier trials that assigned overweight and obese youth to a diet and exercise program or a diet-only intervention. Those programs lasted anywhere from six weeks to six months.
Most studies found kids tended to have a lower body mass index (BMI) – a ratio of weight in relation to height – and a smaller percentage of body fat after completing either type of intervention. Adding aerobic exercise such as jogging or dance to a restricted-calorie diet had little effect on weight loss.
Once again, results like these don’t mean I’m against exercise for fat kids. Here’s why:
However, kids who did resistance training lost more body fat than those who didn’t exercise, according to the analysis. Strength training for an hour or less each week was tied to an extra half a percent drop in body fat and a greater increase in muscle.
Forget the jogging. If you want to improve your body composition, lift some weights. Toned muscles make you look and feel better, whether you lose weight or not.
When the episode of The Men Who Made Us Thin recounted the aerobics/Jane Fonda craze, it occurred to me that waaaay back in the day, I did some bits on those topics in my standup act. So I dug out a box of tapes and found an old Hi-8 tape from the 1990s. Fortunately, I also found my old Hi-8 analog camcorder in the attic and was able to transfer from the Hi-8 to a digital camcorder and then to my Mac. Since the exercise bits were short, I included few minutes on other topics as well. (As was usually the case when recording in a crowded club, you’ll see some good close-ups of a waitress’ head.)