I recently read an article linking testosterone levels in women to libido. After 10 months of working out, consisting of 2-3 sessions weekly on Nautilus weight training equipment with progressively heavier weights, 2-3 aerobic workouts per week, and a modified diet (I'm now 50 pounds lighter), I've found that my sex drive has significantly increased (I'm soon to be 42 years old). Of course, I'm also now totally addicted to working out. I know that it can be attributed to psychological aspects of improved body image, self-confidence, etc., but I was wondering if there are physiological reasons for it also...does increasing muscle mass and decreasing fat also cause a women's body to produce more testosterone?

Congratulations on your impressive accomplishments! You've lost a lot of weight - and you did it the healthy way.

Quite a few women have told us that after they got fit, they experienced an increase in libido. We aren't sure why. As you say, the effect could result from emotional changes - better self-esteem, body image, etc. But there might be physical factors at work as well. We've looked at testosterone levels before and after strength training, but the preliminary data do not show any difference. It's a very interesting question for further research. Perhaps someday we'll have scientific proof that strong is sexy!