Okay, so women have more oestrogen and body fat than men, but why is it seemingly easier for men to lose weight? This can be summed up in one word: metabolism. It's sort of a domino effect in men. They have more testosterone, which allows them a higher percentage of muscle, and because muscle is more metabolically active than fat, it burns more calories and revs up their metabolisms.

What's your 'fattern'?
Female ‘fatterns,’ or patterns of fat distribution, seem to be an issue, too. Male fatterns tend to be highly abdominal, whereas women tend to carry heavier in their lower bodies. And abdominal and visceral fat appears to be more responsive to exercise than the fat on the hips, buttocks, and legs.

Playing it safe
Remember when you could be excused from gym class because you had your period? Well it wasn't just high school PE class that was affected by this taboo. Until a few years ago, most of the International Olympic Committee members believed that sport training and competition were detrimental to proper reproductive functions in women.

We now know that these beliefs are unfounded. Physical activity, whether during the menstrual period or not, will not harm a woman's reproductive organs. In fact, men's testes are actually in a more vulnerable state than women's reproductive organs during certain athletic activities. Hence the need for a ball box!

But do menstrual cycles affect physical ability at all?
There are many personal acounts where women can tell you that while they're pre-menstrual, they just don't feel as strong as usual. “When I'm suffering from PMS," says Angie Boyum, a bodybuilder and trainer, "I just don't have as much energy and I'm hungry all the time!"

Yet despite many testimonies from fit, active women who say they can feel a difference when they are pre-menstrual, there does not appear to be any conclusive evidence of effects of the menstrual cycle on actual athletic performance.

There’s no denying that cramps, bloating and moodiness would make even the strongest among us want to curl up on the couch with the latest chick flick and a slab of chocolate. But research shows that aerobic exercise can help ease many of the symptoms of PMS, so try your best and resist the urge to skip your training session.

Nutritional concerns
One of the top nutritional concerns regarding menstruating women, especially active women, is iron intake. Athletes are at particular risk. The reasons include: