Pretty much all of us women can distinguish phases of our menstrual cycle, from migraines, bloating, cravings, cramps, curves to changes in mood & emotions. But do we really understand our character distinguishing hormones & how these may impact on our fitness goals?
There’s still much to be understood, however, recent research suggests that over half of female athletes reported & experienced negative side effects of their monthly cycles. The way in which females are affected by their hormones is highly individual & some women may experience little to no effect, but understanding the prevalence of these (possible) side effects can really benefit & influence our approach to training. We can also begin to pinpoint fluctuations in strength, metabolism, body temperature, inflammation & even injuries at certain points in the month.
Having your period isn’t quite as worrying or as bad as you may think for sports, as actually this is the time of the month when hormones drop & many female athletes even report Personal Bests. Paula Radcliff broke a world record in 2002 despite suffering period pain during the latter stages of her race.
It’s worth noting however, that the impact of heavy menstrual bleeding for some women can increase susceptibility to iron deficiency & compromised iron stores, in endurance athletes especially, & be significant.
Did you know that our BMR (basal metabolic rate) is reported to drop while we menstruate, reaching its lowest level just before Ovulation (days 1-14 roughly). You may find that your appetite is suppressed & thus you hit that diet head on, problem free. Because of this, some woman may want to consider a lower calorie intake during this period (no pun intended) if maintaining a stable body weight or fat loss is the goal. It’s a stage that I myself see ladies coping better physically & psychologically.
During this low-hormone (Follicular) phase, insulin sensitivity is higher than in the Luteal phase (the high-hormone, latter part of your cycle), intolerance to pain is higher, strength may peak & the body is primed for higher intensity workouts. This is where some coaches may base the periodisation of Strength Training on individual menstrual cycles.
When we experience a spike in testosterone, a well know anabolic hormone, just before Ovulation (increasing libido!) we may also benefit from a nice little energy peak too. You may notice other signs of Ovulation such as a higher body temperature.
With the subsequent rise in Progesterone post Ovulation, our BMR rises & many women experience cravings. These cravings may be to support the additional energy required, or they may simply be that Progesterone (thought of as an appetite stimulant) makes you want more food even though your maintenance calories don’t require too much of it. Female clients can sometimes find this a difficult stage in dieting, & they fear check-ins because of a slower rate of fat loss that particular week. We need to bear in mind that weight is not just body fat. If you’ve stuck to your diet plan, don’t panic if you feel or look slightly ‘rounder at the edges’, the rise in Progesterone actually activates the hormone aldosterone. Aldosterone causes an increase in salt & water reabsorption into the bloodstream from the kidneys, therefore, resulting in water retention, bloating & swelling. Fortunately, these are temporary symptoms & dissipate soon after menstruating.
This surge in Progesterone as well as Estrogen in the Luteal Phase is what can make it harder for us females to make & maintain muscle. Amino-acid oxidation & protein degradation is higher in the Luteal Phase than in the earlier Follicular Phase. Put simply, Progesterone promotes protein catabolism. That’s why smart dieting is particularly important. Consuming protein foods that are rich in Leucine and/or branched-chain amino acids before & after exercise is important. You may also require more carbohydrates for higher-intensity activities, because Estrogen reduces your carb-burning ability. If we don't manage our calorie intake carefully & be mindful when choosing our food sources (remember our BMR rises during this phase of our cycle) we may be met with those cravings again, not to mention a poorer performance in training.
HOWEVER, don’t be alarmed in you have an event during the high (Luteal) phase of your cycle. Research shows that key performance indicators such as max V02 & lactate threshold remain constant throughout our cycles - great news for endurance athletes & sports. This said reaction-times, muscular coordination & manual dexterity may be compromised.
Four-times British Champion swimmer Mia Slevin, Emelia Gorecka a British middle & long distance runner, British Olympic Hockey Gold Medallists Sam Quek & Kate Richardson-Walsh, England Footballer Alex Greenwood, Olympic Althlete Eilish McColgan & the Derbyshire-based Derventio Excel Performance Swim Squad all apparently track & apply knowledge of their cycles to training.
There is an awful lot of information to take on board & learn. And even when you get your head around the textbook theories, you may find that your experience doesn’t even fit it after all. The models & examples mentioned also only refer to females who experience a pretty ‘normal’ cycle. It doesn’t even begin to approach the subject of hormone imbalances or contraceptives.
The best thing you can do is track your monthly cycle. Monitor & record your progress. Find patterns that may be relevant & then apply these to YOUR specific goals. Every woman is unique & different & your plan should reflect that.
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4236309/  Roar, Stacy T. Sims, PhD, pg 20  Roar, Stacy T. Sims, PhD, pg 19