As a gym owner, personal trainer and strength coach this may seem like a self-inflicted shot in the heart but I have to speak the truth as I see it.
One of the biggest misconceptions about exercise is that it by itself always causes weight loss.
This gets especially bad with kids – you can’t spend five minutes in a discussion about childhood obesity before someone starts lamenting that “ Kids These Days Just Don’t Play outside like they Used To “ and if we all just went back to the days of playing tag instead of sitting in front of the TV, childhood obesity would disappear.
But that’s just not the case. There’s no convincing evidence that increasing exercise without changing diet will significantly reduce rates of childhood or adult obesity. In study after study, exercise alone, without change in diet, doesn’t cause any significant weight loss, because exercise alone just can’t make up for a lousy diet.
Although it is true that before video games and Droids we spent more outside playing we also had a better diet. I personally can remember getting a lot of sweets on Easter, Halloween and Christmas and that was about it. Mostly we ate dinner that was cooked at home and had cake on someone’s birthday.
Exercise does have all kinds of benefits for weight loss as an add-on to a healthy diet, and it might make weight loss easier to maintain (by preserving muscle mass and metabolic rate), but it can’t make up for eating poorly. Getting kids to go outside and play doesn’t help if they come inside afterwards and have a Coke and a Cosmic Brownie as a snack, pizza for dinner, and ice cream for dessert. And the same goes for adults; exercise alone has failed again and again to produce any appreciable weight loss. If you’re not eating well, you won’t lose weight by adding exercise, and if you are eating well, any weight loss will probably come from your diet, not from whatever exercise you’re also doing.
But that doesn’t make exercise a waste of time! Even without causing an ounce of weight loss, exercise can provide all kinds of health-related benefits, including some of the benefits you might be trying to get by losing weight. And focusing on those benefits may also make it easier and more pleasant to stick with.