Unfortunately, most women incorrectly believe that the best way to “get muscle tone without getting too big” is to lift light weights for a high number of repetitions. This is not the right approach. Your fears of getting too big are unfounded and without substance. Lifting light weights for a high number of repetitions builds muscle endurance, not strength, and very limited improvement in muscle tone, if any at all, can be achieved through muscular endurance training. You must increase muscle strength to develop muscle tone.
The solution is to lift heavier weights for fewer repetitions and don’t worry about getting too big. It simply won’t happen because women are not physiologically disposed toward putting on muscle mass. Blood testosterone levels for women are typically between 30 to 95 nanograms per deciliter. Compare this to men, who have, on average, 300 to 1,200 ng/dL of testosterone in their blood (reference for blood testosterone levels).
Testosterone is the key steroid hormone responsible for muscle growth, and women have very little of it. Increasing muscle strength does increase muscle size, there’s no doubt about it, but even with a massive testosterone advantage it takes most men enormous amounts of time and dedication to acquire the noticeable levels of muscle mass that so many women are afraid of.
For a woman, it’s true that lifting heavier weights for fewer repetitions will increase your muscle size, but the increase will happen very slowly, and the gains in size will be very small. In fact, the low testosterone levels of women create ideal circumstances for developing the muscle tone that you are looking for. It allows you to gradually put on small amounts of muscle until you have the toned appearance, without too much size, that you desire, at which point you can modify your strength training program to simply maintain the small amount of muscle mass that you have gained. There is absolutely no need to fear that you will “get too big,” because the size increases happen so slowly that you will be able to halt progress at any size you are happy with, without going to far.
If you are a woman and you are still not convinced, just try it anyways. Look at yourself in the mirror every day to monitor your muscle tone and size. The worst thing that can happen is that your fears come true, and you are the one woman on the planet that gets huge muscles after a couple of strength building workouts. If we suppose that this does come to pass (it won’t), then all you’ll need to do is stop lifting weights. You will lose all of your size gains in a very short period of time and your muscles will return to their original size (unless, of course, you also happen to be the only person on the planet that does not experience loss of training adaptations after cessation of training). Just try it, you’ll be happy with the results.