Discover more from Honest Exercise and Nutrition Essays
How the menstrual cycle affects your strength and hunger
Up until the 70s, sports science didn’t even include women in their research. It wasn’t until after 2013 that the first textbook was released on female sports nutrition.
I think it’s more than fair to say that women are exceptional when it comes to our physiology. Every 24–32 days, our bodies go through a series of 4 distinct events known as the menstrual cycle — and it complicates our entire system.
While many are aware of the common premenstrual symptoms such as pain, breakouts, water retention, and cravings, I don’t think many know the effect it can have on our strength and metabolism.
Up until the 70s, sports science didn’t even include women in their research — and — it really wasn’t until after 2013 that the first textbook was released on the earth-shattering idea of female sports nutrition.
To quote Lyle Mcdonald, it was simply assumed that women were just, “little men.”
Even today, roughly 80% of scientific studies exclude female participants altogether, largely because of how unpredictable the hormonal shift can be.
Key Hormones: Estrogen and Progesterone
For those who don’t know, estrogen and progesterone are the key hormones that fluctuate and vary throughout the menstrual cycle.
Estrogen tends to get a bad rap in the industry, but this isn’t really fair; since it’s responsible for a variety of positive training implications such as increasing the metabolic rate, using carbs for energy, and controlling hunger. Most likely due to its effects on leptin. Some studies have even supported that estrogen can hold anabolic properties by increasing the muscle’s capacity to grow and repair.
Progesterone, however, is generally the hormone that makes women feel awful, hungry, and lethargic during their cycle, and worse, some studies suggest it can even block estrogen and cause the muscle to break down (catabolic).
1st Phase: Follicular Phase — Progression and Most Adherent
In 2016, Lisbeth Wikström-Frisén, conducted a study to discover whether using the method of menstrual timing in resistance training could improve muscle growth and strength without increasing the number of sessions.
She divided 59 women into 3 groups (2 interventions + control) for 4 months, where half of the participants performed high intensity and frequency lower body training during the follicular phase of the menstrual cycle, and the other half did the same program but only during the luteal phase.
At the end of the study, Lisbeth found that the group training in the follicular phase saw a greater effect on muscle mass, strength, and power versus the group training during the luteal phase — the same comparison was also made to a control group that consistently performed 3 workouts per week during the entire month (regular training)
In 2005, a study showed that women training in the follicular phase had a higher tolerance for pain, the highest maximum voluntary force generations capacity, and increasing levels of endurance.
In short, it seems with estrogen increased and progesterone normalized, we can recover quicker and more efficiently from more working sets and heavier reps. And this creates an ideal environment for muscle growth.
Nutritionally, studies support that the follicular phase is the best time to start dieting, since your insulin sensitivity and cravings will be at their lowest, and your body will be more likely to utilize carbs for energy.
One study, published in the American Journal of Clinical Nutrition, noted that basal metabolic rate decreased during menstruation and then proceeded to decline to its lowest point one week before ovulation took place. Meaning, that it might be useful to implement carb refeeds during the follicular phase to help counteract the decline in resting metabolic rate.
2nd Phase: Ovulation — Hit Your PR
Halfway through the menstrual cycle (around day 14) ovulation starts and estrogen levels peak. You’ll start to feel warmer and hungrier.
Your strength levels will still be high and you may notice the highest shear force generation capacity during this phase. This could be an ideal time for you to attempt a PR. According to research in the Journal of Physiology, ovulating women showed an 11% increase in both quadriceps as well as handgrip strength.
3rd Phase: Luteal Phase — Cravings and Body Temperature
You know the workouts where it seems your body is just fighting you every step of the way? You feel weaker, bloated, and lethargic?
Chances are it’s all happening throughout the luteal phase.
In the last two weeks of the menstrual cycle, estrogen drops, progesterone increases, and your body temperature rises.
Metabolically, energy expenditure will be at its highest and your body will start to burn more calories (2.5–11.5% increase in metabolic rate) digesting more than it normally does (89–279 kcal per day).
This sounds great for dieting.
However, appetite increases for every macronutrient: protein, carbs, and fats; which have been strongly reported during this phase. And as a whole, most women aren’t particularly good at resisting these cravings either since 85% of them admit to indulging their cravings at least 50% of the time.
That said, not all women have cravings with the same frequency or intensity. Women who tend to have more depressive symptoms during the premenstrual period tend to have more severe cravings.
To make matters worse, with your body temperature higher than normal, you’ll also experience higher cardiovascular strain and a decrease in time to exhaustion. Your body shifts to burning fatty acids for fuel more readily during the luteal phase instead of muscle glycogen (carbs) as we saw earlier in the follicular phase. In short, you’ll fatigue a lot quicker.
So there are more total calories burned throughout the luteal phase, but the real application of this comes down to what the goals are for each individual as well as their ability to cope with dietary restrictions during what can also be the time cravings are at their highest.
In the end, according to Lyle McDonald, “If you’re a woman looking to start a diet in the luteal phase, you’re setting yourself up for failure.”
4th Phase: Menstruation
Menses follows when the woman first bleeds and this is when everything starts all over again.
Estrogen becomes the dominant hormone again while water retention begins to subside, blood glucose, metabolic rate, energy, and body temperature finally begin to normalize.
Thanks for reading! Subscribe for free to receive new articles straight to your inbox.
Resources and References: