I was listening to the radio the other day and they were interviewing a Dr who conducted some research on a physical activity intervention on elementary school children. The segment was introduced as being about obesity. I can’t recall exactly what the intervention was but, naturally, it had no effect on obesity levels in the children.
I know that obesity is the big thing right now (pun totally intended) but I think that we need to stop approaching every study about exercise and nutrition as a weight loss intervention. We already know that diet generally accounts for about 80% of the weight loss equation. Therefore, logically, physical activity interventions are unlikely to have a significant effect on weight.
This focus on obesity causes us to lose focus on other benefits to be had from physical activity. Just because children didn’t lose weight from the intervention doesn’t mean that such interventions aren’t worthwhile. Benefits of physical activity and exercise include: increased healthspan, decreased risk of many chronic diseases (e.g. depression, type 2 diabetes, heart disease, some forms of cancer, osteoporosis, dementia), stronger immune system, increased energy, better quality of sleep, etc. I always say that exercise is my drug of choice.