You may have noticed that some days you're totally killing it in the gym, with your diet and overall mood and other days are not able to lift the same weight, also you may experiencing mood and motivation swings.
All these mental, hormonal, and metabolic changes can be hard to handle but the understanding of your body, cycle, hormonal and metabolic changes, can help you accept and adapt to these expected situations.
The menstrual cycle is the result of a complex series of hormonal changes involving the hypothalamus, pituitary glands, and ovaries (HPO axis). These important organs are instrumental to the development and regulation of body systems, like her reproductive and immune systems.
A normal menstrual cycle can be anywhere between 28 and 35 days. It can also differ in the length of time, month to month. Encourage yourself to track your cycle so you get a better understanding of what 'a normal' cycle looks like.
We know that every woman is different when it comes to her cycle. However, science can help us to understand how a woman's body changes through a cycle and how to work with it, instead of against it, to obtain the best possible results in and out of the gym and stay on track.
Women experience monthly fluctuation in certain hormones and through the cycle, as well as changes in exercise metabolism. That means the fuel source you use is dependent on the concentrations of progesterone and estrogen at certain times of the month. At a certain phase of your cycle, your body will have a preference for burning sugar or fat as fuel & you can manipulate your nutrition and training accordingly to give yourself a little competitive edge. Exercise metabolism or the fuel source you use is dependent on the concentrations of progesterone and estrogen at certain times of the month. Yet you can also use these hormones when training, wanting to gain muscle or lose fat.
Estrogen is known to reduce carbohydrate oxidation and increase free fatty acid availability. This means when estrogen levels are high, you will tend to conserve glycogen stores and utilize more fat as fuel. For longer endurance events (for example marathon) this could potentially be beneficial. But this glycogen sparing mode might make it more challenging to reach higher intensities. Supplemental carbohydrates are important in this phase. In other words, if you are in a high hormone phase, you might find you need to take in a few extra carbohydrates to get a similar higher intensity performance as you would without supplemental carbohydrates in a low hormone phase.
Progesterone promotes protein catabolism, and some studies suggest ingesting BCAA's pre-exercise during the mid-luteal/high hormone phase. Protein ingestion is also important for female athletes in regards to recovery. The recovery window is a lot tighter for women, as we return to basal metabolic rates within a few hours. For harder efforts or training of long duration, that 30-60 minute window to consume post-workout protein and carbohydrate is a lot more critical for women.
Some recent studies have shown that overall energy intake rises by 12-38% from the follicular to the luteal phase. This is why you may notice changes in weight as your weight peaking two times during your cycle. Once, during the early menstrual phase and the second immediately after ovulation. These peaks are caused by changes in water balance (water retention), colonic function, and overall intake.
The main woman's hormones playing a role in a woman's cycle are:
Oestrogen – the primary sex hormone in women;
Progesterone – helps thicken the lining of the uterus; when levels drop, your period begins.
Follicle-stimulating hormone – helps follicles (which hold the eggs) in the ovaries mature
Luteinizing hormone – stimulates ovulation
The hormones also play a very important role in plasma volume regulation. Plasma volume is basically the volume of fluid in our blood. Our fluid volume in relation to solutes (ie sodium, potassium) is important. When hormones are high, the estrogen and progesterone cause a drop in plasma volume by about 8%, so think thicker blood. Improved endurance performance typically comes with higher plasma volumes, so we have to pay closer attention to hydration in this phase. Women are more predisposed to hyponatremia during this phase as well because progesterone increases total body sodium losses.
There are three main phases in the menstrual cycle that we need to be aware of – the follicular phase (the first week is considered as a menstrual phase), ovulation, and the luteal phase. Let's break down each phase and how you can adapt your training.
MENSTRUAL PHASE DAY 1 - 5
The menstrual phase starts with the first day of bleeding. During this time, estrogen and progesterone are super low, which can make you feel tired. And another hormone — prostaglandin — is at an all-time high, which is why you might experience painful cramps.
Rest is key. However, some gentle exercises such as yoga, pilates, stretching, or just walk, will help you decrease those cramps and make you feel better.
FOLLICULAR PHASE DAY 6 - 14
At the end of the second week of your cycle, your estrogen is starting to rise which means bringing more energy. The late follicular phase is great to start with some high-intensity exercise, strength training, or Crossfit. You may notice a higher pain threshold, increased agility, and muscular endurance.
Estrogen also helps from a recovery standpoint as the hormone release of estrogen has anti-inflammatory effects. During this phase, your blood glucose levels are more stable so you’re more likely to adhere to your diet. You also metabolize carbs more efficiently during this phase.
OVULATION PHASE DAY 15 - 17
During the ovulation phase, your testosterone and estrogen are peaking. So, if you are looking to hit some PB's, now is the time. One sign that you are ovulating is a slight rise in body temperature, which happens around day 14 of your cycle. Surging estrogen levels can provide a natural energy boost at this time of the month, so while maximizing your potential, making good quality sleep vital for rest and repair.
Hormone shifts around ovulation have been known to increase sugar cravings so prepare yourself. Stabilize cravings by ensuring you’re eating enough protein, micronutrients, and healthy fats.
LUTEAL PHASE DAY 18 - 28
During this time, progesterone is on the rise as testosterone and estrogen deplete. You may be experiencing low energy levels, increased irritability, bloating, headache, food cravings, breast tenderness, and trouble sleeping. You may also notice weight changes and water retention, so don't be alarmed.
Optimal activities in this phase are strength training with lower volume, pilates, or some cardiovascular training.
The best thing you can always do is to listen to your body and rest up when you need it.