Tip: Women Shouldn't Fear Big Weights

Researchers from Coastal Carolina University recruited 20 female students and divvied them up into two groups. Each group trained upper body twice a week and lower body once a week for 8 weeks.

One group trained with relatively heavy weights and did 6-7 exercises for sets of 5 to 6 reps (over 85% 1RM). The other group did the same amount of exercises but trained with lighter weights, doing sets of 10-12 reps (50 to 70% of 1RM). All test subjects worked to momentary failure on each set.

Both the heavy and lighter groups attained similar increases in lean body mass (more so in the lower body than the upper body, though), thigh cross sectional area, vertical jump, chest pass velocity (with a medicine ball), back squat maximum, and overhead press. Likewise, both groups lost significant amounts of body fat.

Even so, the gains were modest, with test subjects gaining a little size in thigh cross-sectional area and hardly any in their upper body.

The researchers concluded that the "the data obtained in this study also serve to further debunk some of the myths that may otherwise impede young women from strength training, including a fear of excessive hypertrophy."

• Women should use weights of at least 50% of 1RM to favorably change their body composition, but that may need to be re-addressed as they lose their novice status (they may need to use heavier, more challenging weights).
• Using 50% of 1RM might be useless, though, unless women train, at least a good percentage of the time, to momentary failure – to the point where they can't perform another rep. To do this, women need to lose the fear of "making ugly face." (Personally, I almost never see women grimace in the gym. They should try to overcome their fear of looking unfeminine, at least for a couple of instantly forgotten seconds.)
• Regardless of whether they train with lighter weights for high(er) reps or heavier weights for low(er) reps, it's not going to make them "bulky," at least without undertaking drastic increases in training volume, intensity, and complexity with appropriate dietary changes (more calories and more protein).
• For optimal results, women should adjust their protein intake to roughly 2.0 grams per kilogram of bodyweight. This is good advice for women who simply want to have a beach bod, or who ultimately want to gain an appreciable amount of muscle mass.

Note: The researchers in this study didn't make changes to the test subjects' diets, but they did monitor them. They found that their protein intake was low, falling well short of the NSCA recommended 2 grams per kilogram. More energy intake, i.e. calories, along with additional protein would likely have made the muscle growth more "robust."

1. Cholewa JM et al. The Effects of Moderate- Versus High-Load Resistance Training on Muscle Growth, Body Composition, and Performance in Collegiate Women. J Strength Cond Res. 2018 Jun;32(6):1511-1524.