Being inactive can bring negative health consequences that go well beyond lack of muscle tone and problems with weight management. A study published in the European Journal of Applied Physiology details some of the unseen differences between women who lead sedentary and active lifestyles.

Researchers recruited 20 inactive females in their mid-20s and assigned half of them to train with weights for about an hour 3 times weekly for 12 weeks. Their workouts consisted of chest presses, leg extensions, shoulder presses, leg curls, lat pull downs, leg presses, arm curls and triceps extensions. Resistance was set at 65% to 80% of one rep max. Compared to subjects who remained inactive, the weight training subjects had increased levels of estrogen and testosterone along with improved bone health.

True Strength Moment: The researchers leading this study didn’t report changes in body fat and muscle mass, but you can imagine that those elevated levels of natural growth hormones were helping to build more than just bone density.