Women’s Health: Take the Mystery Out of the Menstrual Cycle

The key to good nutrition for women lies within our hormones.

If you’re reading this article, you’re likely a woman who has struggled with weight at some point in their life. Possibly many points in their life. Maybe you’ve tried some fad diets, and maybe some of them even worked. But I’d bet you still aren’t getting the results you want. If that’s the case then you’ve come to the right place for some advice.

The key to good nutrition for women lies within our hormones. Men have the luxury of having relatively stable hormones day-to-day, but women need to understand and work with their menstrual cycle to find a nutrition plan for them to perform their best. For a long time, menstrual cycles and their role in female performance and nutrition were under-researched and thus not well understood, but fortunately for us Dr. Stacy Sims, PhD has done a lot of work to take the mystery out of the menstrual cycle.

In general, your body needs a variety of macro-nutrients throughout the day. Macro-nutrients include carbohydrates, fats, and protein. Dr. Sims recommends 40-45% whole food carbohydrates, 0.8g of protein per kilogram of body weight (about 30-35% daily calories), and 30% daily calories from fat.

Carbohydrates are important, as they are our bodies’ primary fuel during exercise. If we don’t consume enough, our bodies start to breakdown muscle tissue to use protein for energy. The trouble with many diets is the elimination of carbohydrates. When women don’t consume enough carbs, our bodies think famine and go into survival mode. Estradiol drops and the hormones cortisol and estrone signal your body to store more fat. Thus, it is important to make sure whatever diet you follow, you are taking in sufficient carbs to fuel your body and to not signal this effect.

Protein is a great diet tool to help you lose weight, build muscle, and recover from exercise. According to the National Strength and Conditioning Association (NSCA), those looking to get involved in a general fitness program should consume 0.8-1.0 grams of protein per kilogram of body weight daily. Those involved in aerobic endurance exercise such as running, cycling, or swimming should consume 1.0-1.6 grams of protein per kilogram of body weight. Strength and power athletes, such as lifters, Cross Fitters, and sprinters should consume 1.4-1.7 grams of protein per kilogram of body weight. According to the NSCA, muscle is most receptive to amino acids immediately after exercise, thus it is beneficial to consume 20-48 grams of protein immediately after exercise to rebuild muscle and help the body recover after exercise.

Fat gets a bad name, but when you examine diet a bit closer it is essential to our daily life. Lucky for us women, estrogen increases the amount of fat burned for fuel, particularly with aerobic exercise. This means we need to get an adequate amount of fat in our daily diet, our body is going to eat into those precious protein stores. The key here is including quality fats, such as omega-3 fatty acids found in fish, nuts, and avocados, in our diets to make sure we can perform well in every workout.


The phases of a woman’s menstrual cycle can be divided into two phases- the low hormone phase and the high hormone phase. Day 1 is the first day of your period. The low hormone phase is days 1-14, where hormone levels are relatively low and we are most physiologically similar to men. Around day 12, estrogen and luteinizing hormone surge for ovulation. The high hormone phase is days 15-28. This is when estrogen and progesterone levels rise. Your body burns more energy during this phase to prepare the body for a possible pregnancy.

But what does all of that mean for you? According to Dr. Sims:

  • Estrogen reduces the ability of our bodies to make muscle and reduces our ability to burn carbs, but increases fat burned for fuel.
  • Progesterone delays sweat response and increases core temperature, sodium loss, and muscle breakdown.
  • During the high hormone phase, your body is preparing itself for a possible pregnancy, meaning there’s less energy available for you to use during workouts. Your body has less ability to build muscle and is more likely to break down the muscle you do have. Delayed sweat response and increased core temperature makes it harder to exercise in hot conditions, and more difficult to cool your body during a workout. Increased sodium loss makes it more difficult for us to stay properly hydrated.

Now all of that might make you feel like the odds are stacked against you, but there are ways we can work with our hormones to make sure we feel our best no matter what time of the month it is. Dr. Sims recommends increasing protein and BCAAs, especially leucine, to decrease mood swings and lost motivation to workout. Consuming protein within 30 min of exercise can also help combat the effects of estrogen and progesterone on muscle. Drink a large bottle of low carbohydrate hydration drink every hour you exercise to combat increased core temperatures and decreased sodium. Increasing consumption of foods with magnesium and omega-3 fatty acids can reduce cramps and GI distress that can plague so many of us in the weeks before our periods.


As your body goes through new hormonal changes, you’re likely to notice changes such as increased body fat, insomnia, and hot flashes. Much of this can be attributed to the decline of estrogen. Based on what we learned earlier, decreased estrogen may sound like a good thing to make and build muscle, but postmenopausal women still struggle to build and maintain muscle mass. This is due to an increase in protein breakdown and less sensitivity to the muscle building effects of exercise and protein consumption. The key to combating this is to increase protein in your diet. Dr. Sims recommends consuming 15g whey protein 30 minutes before training, 25g mixed whey isolate and casein 30 min post-exercise, 20-25g whey isolate and casein within 2 hours after exercise, and 10-15g before bed.

The decrease in progesterone and estrogen makes it more difficult to fall and stay asleep. Research has shown Valerian root and tart cherry juice can help you fall asleep faster and stay asleep. Decreased estrogen also contributes to hot flashes. Research has found that after menopause women sweat less, have a higher core temperature, and are less likely to feel thirsty. Dr. Sims recommends staying hydrated and keeping your water bottle icy cold to reduce core temperatures.

Remember, Good Habits Take Time

Overall, it is important to remember good habits take time and you need to be patient with yourself. Everybody’s bodies are different and nutrition is not a one-size fits all topic. When in doubt, eat more protein and drink more water. If you would like to learn more about this topic, we’d encourage you to read Dr. Sims’ book Roar or reach out to a dietitian to figure out a diet program specific to your body.

If you’d like to speak to a Women’s Health expert at Body Gears, we encourage you to locate one of our six clinics nearest you. With 24-48 scheduling and complimentary screenings, Body Gears is just a quick phone call away from getting your health back on the right track.