Considerations For Female Athletes
There is no shortage of training recommendations out there. They help athletes plan training volumes, intensity, nutrition and even sleep. The problem is, most of these recommendations have been made using research based on young men and do not translate into the same results with females.
The menstrual cycle works hand and hand with training but is not always something female athletes or their coaches consider. We would like to help change this! We often refer to Dr. Stacey Sims for resources on how the menstrual cycle affects training. She is leading the way and helping normalize this conversation and highlighting the research (and lack thereof) on this really important topic.
Have you ever noticed that at certain times you can push harder and still feel great? Or the opposite - no matter what you do you still feel sluggish and tired?
Having knowledge on what occurs during the different phases of the menstrual cycle can help women make better choices about training, recovery, and nutrition. It can also alleviate potential frustrations by helping you understand your body and why you may be experiencing certain symptoms before, during, or after training.
The female body responds differently to exercise stress depending on what phase of the menstrual cycle they are in. There are patterns in the various stages of the menstrual cycle that help inform females of the overall health of their endocrine system, how their bodies will tolerate stress, and specific fuel and supplement requirements.
Without further ado let's review the two main phases of the menstrual cycle; the follicular and the luteal phase.
1️. Follicular Phase
This phase begins at the onset of menses until ovulation. The duration varies between individuals from 10 to 16 days.
It is characterized by having low levels of progesterone, and low but gradually increasing levels of estrogen. During this phase there are several important physiological changes that are important for performance:
Lower core temperature
Improved carbohydrate utilization
Elevated circulating sodium so more water is in the blood vs in the extra-cellular space
Lower basal heart rate
All of these are beneficial for performance as women will have access to a faster energy source, higher blood volume to get oxygen to working muscles, and a lower heart rate for a given work output. Basically women will feel bullet-proof during this phase. This is time to do the intense sessions and work hard!
2️. Luteal Phase
The luteal begins after ovulation and lasts until the onset of menses. The duration is fairly consistent between women at 14 days. It is characterized by high levels of estrogen and progesterone.
During this phase women experience:
Elevated core temperature
Improved fatty acid oxidation
Reduced carbohydrate utilization
Reduced circulating sodium so more water is in the extra-cellular space
Serotonin is up-regulated, creating brain fog
Increased basal heart rate and breath rate
During the luteal phase, women push water to the skin in an attempt to reduce core temperature, lowering blood volume. As a result women experience higher ventilation and heart rates in order to sustain delivery of oxygen to the working
muscles. Hard sessions will feel harder than usual and the mental skills necessary to complete hard workouts will be inhibited. This is the time to dial back the intensity and work on aerobic base and lower thresholds.
If this is not something you’ve considered in your training, then we recommend starting by tracking your menstrual cycle to to build awareness and identify patterns around your (or your athlete’s) menstrual cycle and its effects on training. There are apps that help with this, which can be kept personally or shared with a coach.
Below are some helpful resources:
ROAR - by Dr. Stacy Sims
Menstrual tracking apps:
Wild AI - Apple, Google Play
FiTRwoman - Apple, Google Play
Clue - Apple, Google Play