Is The Pill Sabotaging Your Fitness Goals?

How and whether hormonal birth control contributes to weight gain has been a debate since the introduction of the pill. While studies suggest that the weight gain caused by the pill is most likely due to water retention or is minimal, there are other studies pointing toward a negative effect of the pill on body composition. In short, it may contribute to decreased muscle mass, strength gains, and thereby, reduced metabolism.

True, testosterone is often thought of as the "male sex hormone," but it's an important hormone in women’s health too. Testosterone plays a role in our mood, heart health, bone strength, libido, and muscle mass. And while it can cause acne, oily skin, and hair loss when out of balance, it is still an essential part of your health.

Acne and PCOS are some of the primary reasons women are prescribed the pill for noncontraceptive reasons. That is because the pill is effective at lowering total and free testosterone, by decreasing the ovaries' production of this hormone, by as much as 50 percent. While women are on the pill, they experience higher levels of sex-hormone-binding globulin (SHBG), which binds free testosterone. So in addition to reducing testosterone production, it also binds to free testosterone available in the body.

As I explain in my book, Beyond the Pill, testosterone is rising in your cycle leading up to ovulation, during the follicular phase. Research shows this is a time when our metabolism also speeds up, which means there is an opportunity to make gains in muscle mass and strength training. Your follicular phase is a great time to lift weights and build muscle. Testosterone has been shown in studies1 to increase our muscle mass through protein synthesis.

In a natural menstrual cycle, you will also experience a rise in your metabolic activity and will burn more calories during certain times in your cycle due to hormonal fluctuations around ovulation. Unfortunately, while on the pill, you aren't ovulating and therefore won't enjoy the bump to your metabolism.

Over the years, you might have heard recommendations that athletes begin or remain on the pill to overcome the decrease in exercise tolerance during the luteal phase. And while some studies2 have shown a decrease in time to exhaustion during the luteal phase, other studies have noted that in temperate climates, there is no decrease in female athletic performance during the luteal phase. In fact, a 2003 study published in the Medicine & Science in Sports & Exercise3 concluded that "regularly menstruating female athletes, competing in strength-specific sports and intense anaerobic/aerobic sports, do not need to adjust for menstrual cycle phase to maximise performance."

If you feel like your adrenals are shot and you're having episodes of hypoglycemia, then it may be necessary for you to eat regular meals. Otherwise, I encourage patients in my practice to engage in intermittent fasting with a simple practice of shutting down the kitchen at a certain hour in the evening and then not eating again until 12 or more hours the next day. Intermittent fasting has been shown4 to be effective for weight loss but, more importantly, helps maintain your lean body mass (aka muscle).