How exercise affects the menstrual cycle. The menstrual cycle is an integral part of a woman’s life, knowing how to exploit it could give an advantage in terms of performance and general health.
Let’s discover the relationships between exercise and a woman’s menstrual cycle!
Which is Menstrual Cycle?
The menstrual cycle is the result of a complex series of hormonal changes involving the hypothalamus, pituitary gland, and ovaries.
These organs are essential for regulating bodily functions and for the functioning of the immune system.
A menstrual cycle can usually fluctuate between 25 and 35 days, its variability can also occur from month to month.
The main hormones involved in the menstrual cycle are:
- Estrogen: Often blamed for making the body fat and weak, estrogen is actually an anti-catabolic hormone and promotes muscle repair. The bad reputation of estrogens in sports is due to their indirect involvement in the abuse of performance-enhancing substances by male athletes. However, it should be remembered that even in humans there can be no muscle growth without the presence of estrogen.
- Progesterone: Estrogen antagonist, is responsible for the loss of muscle mass and inhibits the motor cortex, reducing the ability of the brain to recruit muscles. The relationship between Estrogen and Progesterone determines the influence of female hormones in the training session.
The menstrual cycle is divided into phases:
- The follicular phase, in turn, divided into the pre-antral, antral, and pre-ovulatory phases, lasts about 10 days;
- Ovulatory phase, lasting about 3 days;
- The luteal phase, about 12 days
- Menstrual phase, from 4 to 6 days
Training and Follicular Phase:
During the follicular phase, the egg is released from the follicle, the peak of estrogen makes it optimal for strength training, hypertrophy, and duration.
The hormonal profile in the follicular phase has a positive effect on strength (maximum voluntary contraction), the ability to metabolize carbohydrates, and pain tolerance.
The training in this phase can be focused on strength sessions with medium-high loads (from 70% to 90% of the maximum) with series ranging from 3 to 6, recoveries over 2 minutes, and the use of exercises involving large muscle masses.
During the follicular phase, thanks to the presence of anabolic hormones (estrogen and increased insulin sensitivity), it is also possible to increase the weekly training sessions compared to other phases of the cycle.
Training and Ovulatory Phase:
During this phase, the mature oocyte is carried into the uterine tubes, and the secretion of estrogen and testosterone is at its maximum levels.
The hormonal profile that occurs during ovulation is the most suitable for testing the maximal strength or endurance.
Training and Lutea Phase:
During the luteal phase, there is an increase in progesterone at the expense of estrogen, the body temperature will be higher than normal and you will experience greater fatigue during cardiovascular activities.
In addition to this, water retention due to PMS will likely occur making high-intensity activities uncomfortable.
The training schedule at this point in the cycle shifts to medium-low commitment, low-intensity cardiovascular activity in the weight room exercises.
Basal metabolic rate accelerates by 7% and digestion-induced thermogenesis will be greater (reason for the rise in body temperature).
Another consequence of the luteal phase is the lowering of the production of serotonin (the “happiness” hormone), which leads to a worsening mood.
To compensate for the decrease in serotonin, the desire to consume carbohydrates will increase.
However, due to insulin sensitivity now being at its lowest, and since the intensity of workouts is lower due to high fatigue, carbohydrate intake must be kept in check.
With the higher metabolic rate and more moderate training intensity, the luteal phase is the best time to switch to a hypoglycemic diet with a lower calorie intake, to stimulate more lipid oxidation.
In this phase, it is very important to listen to your body by supporting it and not to oppose it by imposing exhausting workouts.
This does not mean stopping your workouts, but rather working the exercise technique with low loads.
If during these days, even thinking about training creates discomfort, skip it without feeling guilty; soon there will be an improvement in mood and availability of energy.
Transition Phase or Menstrual Phase:
In this phase, the decrease in the production of estrogen and progesterone determines the flaking of the endometrium with consequent bleeding.
At the end of this short phase, the body temperature will stabilize at normal levels and the energy levels will return to have a positive trend.
During the most intense flow days, unloading days can be scheduled to allow for optimal recovery and a trauma-free transition to the new ovulatory phase.
There are several studies done on periodic training following the menstrual cycle and they go in the direction of training with greater frequency and intensity during the follicular phase.
To seek greater increases in performance (from 30% to 50%) compared to training programs that do not take into account female hormonal fluctuations.
However, over the years he has tested these indications on different control groups, obtaining conflicting results, no better than the placebo effect. Between theory and practice, what can we take home?
Training and body composition are influenced by multifactorial parameters in which progesterone and estrogen are just two actors in a much larger show.
Programmed training and nutrition without taking into account the remaining 99% mean having a reductive view of the factors, especially in light of the fact that the cycle can vary from month to month, always having to adapt your training/diet to this.
Women, in general, respond better to constant stimuli rather than sudden variations, taking into account the cycle can certainly be an interesting factor but starting from this could have a reductive vision of the complexity of all the factors that come into play.