Exercise stimulates and remodels the pituitary – and those of us with hormonal challenges, i.e., sluggish thyroids, polycystic ovarian syndrome and/or insulin resistance, slow metabolism, leptin resistance, adrenal dysregulation, perimenopause & menopause need this.
To be honest, I know I need to exercise, I know what it does to my heart and resting metabolic rate and how when I lift weights, the improved fat-burning benefit stays with me most of the day, and in some studies, for 48 hours.
But this girl needs ongoing motivation and fresh reminders on, well, nearly a daily basis to stay in the groove with exercise and keep it a priority amidst the many competing priorities of kids, work and more fun things such as emptying the dishwasher.
BTW, did you notice that the max heart rate in women was just updated? And turns out we don’t have to push so hard? Check out the New York Times a week ago for the details. This is important to our conversation, so here’s the latest recommendation for women: 206 – 0.88(age). For me at the age of 43, that’s 206 – 0.88(43) = 168, whereas using the old formula of 220-age, I used a max heart rate of 177. This is good news for those of us daunted by exercise.
Let’s take each hormone and describe the “why bother?”
Thyroid. Regular intervals of exercise cause a pituitary-thyroid reaction that leads to increased turnover of thyroid hormones. In fact, when sedentary women start training for a marathon, a moderate hyperthyroid state occurs initially, yet they do not develop the typical hyperthyroid symptoms. Peak rate of increase of thyroid hormones occurs at 70% of maximal heart rate, and this applies to production of both T3 and T4. In my example, I need to exercise at 0.70 (168) = 118 to get the greatest benefit in rate of production of T3 and T4.
Estrogen. Exercise effect on estrogen levels is a little more complicated, but the best short version is that exercise optimizes the efficiency of estrogen. Exercise clears excess carrier protein, so that estrogen enters your brain and muscles more efficiently. This is especially good news for women aged 40+ because the bad news at our age is that our brain becomes less sensitive to the benefits of estrogen (such as my favorite: it raises your serotonin, rather like nature’s Prozac) starting in perimenopause. More estrogen in the brain = more rapid firing of neurons, as many of you know who have been post-partum or menopausal: low estrogen makes you sometimes feel like there’s a short in the brain circuit as you struggle to find words, remember why you walked into a room, or to return to your train of thought in a conversation. Additionally, when you burn fat with exercise, you make less estrone, the “bad” estrogen associated with greater risk of cancer. When your flow of estrogen is more even and steady, your kidneys function better too – and that means less fatigue and cramping.
Testosterone. Increases with intense exercise of 30 min or less (think sprinting, lifting weights) but decreases with longer duration. Rise in testosterone lasts for 45-60 min, then lowers when cortisol starts to rise. Keep this in mind, my Polycystic Ovarian Syndrome (PCOS) friends, when getting your labs drawn.
Insulin. Improved by exercise. Duh… I know you know this. Exercise gets your insulin to transport glucose into muscles so that calories can be used as energy rather than immediately converted to fat on your thighs, and the benefit lasts up to 48 hours. Even 5 pounds of weight loss can significantly improve your fasting insulin levels (goal is < 7), and for those of you still waiting for this benefit to happen, sometimes the problem is that synthetic hormones, such as in the birth control pill or the Nuvaring, can interfere.
Leptin. Consistent exercise lowers leptin. Remember from my post, “Imma Be Queen of Leptin,” that the goal with your leptin is a level of 4-6. Ideal, based on studies, is 60 min, 4 days per week, but if 20 min is what you can manage – you’ll still get a benefit. Note that testosterone levels drop in women who exercise for 60 minutes or more, so with PCOS the longer duration is optimal.
Growth Hormone. Are any of you spending thousands of dollars per month to inject this stuff? Good news: you can raise your growth hormone for free by exercising at your anaerobic threshold, which is at 80% of your maximal heart rate. Using me as an example again, this would be 80% or higher of 168 = 134+ beats per minute.
Overall, the message here is that exercise majorly optimizes your hormone balance. Throw on the walking or running shoes and just get out the door, no matter what.
Written by Sara Gottfried, MD