Luckily, most women aren't afraid to lift weights these days, but many still avoid going too heavy. We're talking about sets of around 3 maximal reps here. Too bad for them, because females may benefit from heavy training even more than men.
It all comes down to growth hormone. Where the male body relies more on testosterone to reap the benefits from weight training, the female body relies a bit more on growth hormone. Natural growth hormone plays a big part in both muscle and bone development. It also improves metabolic function and staves off tissue breakdown.
So, GH is good. And heavy lifting stimulates more growth hormone release in women.
One study on women looked at the effects that different kinds of weight training had on growth hormone. Researchers found that growth hormone was responsive to moderate (around 12 reps) and heavy (around 3 reps) lifting regimens.
"Since women rely on growth hormone to increase muscle and bone strength, the more growth hormone stimulated by a type of exercise, the better its outcome," researchers said.
The study had women weight training with different rep ranges for 24 weeks, complete with lots of blood tests. The heavier weight training protocols produced more biologically active growth hormone. Lead researcher William J. Kraemer noted: "Women need to have a heavy loading cycle in their resistance training routines."
Now, there's muscle-building value in lifting lighter weights too, like increased time under tension. But this study tells us that women shouldn't get stuck in the pattern of using only higher rep schemes and "going for the burn." Those heavy sets, as heavy as 3 grunting reps, may be where a lot of the magic happens.