Imagine two people. One is a man, the other a woman. They both stand in front of the free weights at their gym. They are both going to do overhead presses; in other words, they'll hold a dumbbell in each hand with a bent elbow at their shoulders, then straighten their arms and lift the weight over their heads.

The man holds a total of 30 pounds; the woman lifts 8. He does 8 repetitions, while the woman, who only has 4 pounds in each hand, does 18 repetitions. They are both tired at the end of their sets. Which one has done the correct workout?

Traditionally, men have lifted larger weights and done fewer reps for a combination of reasons. First, men are naturally stronger, and so they can lift heavier weights. Men also tend to want to make strength gains. For example, a man in a gym might want to become stronger, and thus hopes to eventually lift heavier weights as he progresses, while a woman simply wants to reshape her muscles and doesn't really care about being stronger per se.

Early in the research, women were advised to lift lighter weights and do more reps to make some sort of strength gain. But that really didn't work. The truth is, women should do the same number of reps and sets as men, and use a weight that works for them, which will be less than what men use simply because of basic muscle strength. For you to determine how much weight to use, you have to try out each exercise and see what weight will bring you to failure within the number of exercises you're doing. In terms of relative strength, the woman may make great gains — getting much stronger than she used to be — but she will never get big like a man, nor will she lift as much as a man. There are specific training programs using very heavy weights and low reps for body builders, but for your purposes, basic strength-training programs will work for both men and women.