Low BMI, body weight and excessive exercise.....unhealthy????? (Read 1700 times)

I don't run for health.

Your BMI is healthy.

True. It's a fortunate side-consequence of being a runner. I like the fact that running leads to more healthy consequences than unhealthy ones. And it's one of many reasons why I run. However, if I was more focused on health, I would probably run less, swim more, lift more, not try to push through certain injuries. I wouldn't race marathons or ultras. I wouldn't see how far my body can go without breaking. I wouldn't be sick as often during bouts of heavy training. Health is not a bottom-line for me. It may be for some. But if it turned out that my running has taken 5 years off my life, I hope I can say that whatever I miss in quantity has been made up in quality--doing the thing that I love.

I hurt my knee doing something totally non-running. I`m just waiting to hear the dreaded, "Well, your knee was probably already weakend from all that running you`ve been doing."

I would argue that anything can be bad for you when taken to an extreme. Running, weight, whatever. To be totally fair, there is a real problem with running and eating disorders among young women (http://runningtimes.com/Article.aspx?ArticleID=3769). For jkw0989 in particular, as long as his BMI is in the normal range, he's probably fine. But I would try to keep it above 18.5, and if it drops below, consult a doctor. Edit: I was looking into what spaniel said about correlation vs. causation in these BMI studies. It turns out there has been some research into why people with low BMI have higher mortality. This study (http://www.ncbi.nlm.nih.gov/pubmed/7637744?dopt=Abstract&holding=npg) found that lean women (BMI < 19.0)="" had="" the="" same="" risk="" of="" mortality="" as="" normal-weight="" women="" once="" they="" controlled="" for="" smoking="" (i.e.="" many="" lean="" women="" smoke).="" another="" study="" />http://www.ncbi.nlm.nih.gov/pubmed/7840109?dopt=Abstract&holding=npg) looked at older people and found that the high mortality rate for older people with low BMI can be explained by weight change -- people who lose more than 10% of their body weight between ages 50 and 70 have high mortality, and when you control for that it eliminates the higher risk of death associated with low weight. Short version: There seems to be some truth to the idea that low BMI itself is not the cause of the increased health risk, but is instead a symptom of other factors (smoking, declining health) that increase the risk.