The great objection to women exercising is the fear of becoming muscular. Women are physically and entirely different than a man. In women the muscles simply become firm, close-knit, and well-rounded, and show under the layer of fatty tissue intervening between muscle and skin only in soft, hardly discernible masses. The average woman (that’s you) cannot achieve a masculine monster look simply through strength training.
To be serious about strength training, eliminate the T-word-”tone”-from your vocabulary. Lifting a tiny weight for a hundred reps is a waste of time and energy, plus it never really stresses your muscles enough to make them much stronger. According to one study in which men and women trained the same muscle group 3 days a week for 20 weeks, “the women made significantly greater relative increases than men in strength.” (MacDougall et al, McMaster University)
Women and men have exactly the same skeletal muscle composition. It would not be possible to tell biological sex from muscle tissue alone.
In technical terms, “tone” refers to the ability of the central nervous system to provide passive muscular resistance to being stretched. What you probably think of as “toned” are muscles which are not hidden by a lot of body fat. By building muscle, we can speed up our metabolism, resulting in more effective fuel (calorie) consumption. More muscle means less fat in the long run. Where do we find the largest group of muscles in a woman’s body? Her legs and butt. Neglecting these areas, means neglecting the best area for building calorie-burning muscle. In addition, women tend to have much better lower-body than upper-body strength, so it’s very satisfying to work the lower body and see some great results!