Elite. Winning. but Deteriorating, pt II
Female physiology implicates the response and adaptation to training - especially endurance athletes. The menstrual cycle is composed of two phases, the follicular phase, in which time frame (about 14 days in duration) concentrations of estrogen are on the rise. The luteal phase is the second half of the phase (about 14 days in duration), in which concentrations of progesterone rise, and estrogen concentrations simultaneously fall. “Estrogen and progesterone concentrations influence exercise and training. Both of these hormones affect breathing during strenuous exercise, and may affect the perception of difficulty of a training bout” (Karp, Smith; 2012). Estrogen affects baseline body temperature, which results in an athlete sweating at a higher temperature. This hinders your ability to release heat, as the athlete’s ability to dilate the small blood vessels under the skin decreases. As progesterone levels fall before the period, excess water and electrolyte retention cause bloating. Due to these systemic results of hormone concentrations, there are training schemes that work with the female cycle, to allow adaptations as the body changes responsiveness to training stimuli.
Here is a general structure of how to structure training effectively around the menstrual cycle, for female athletes of any sport affiliation (ATPScience, 2020):
Follicular phase: Week 1 of Cycle: ( period ) = athletes will feel stronger, but feel less energetic. Speed/power/ and strength endurance to emphasize lean mass is appropriate training focus.
Follicular phase: Week 2 of Cycle: (ovulation window…) = athletes will have more motivation, drive, and energy. Training here could appropriately be heavier strength training ( hitting PR’s), and mentally fatiguing high energy output/ work capacity training.
Luteal phase: Week 3 of Cycle: athletes feel energetic, but may be experiencing slower digestion/ constipation. Training focus could be high intensity interval training, long slow distance training, and higher volume OR higher intensity strength training
Luteal phase: Week 4 of Cycle: (right before period onset) = athletes may feel extra hungry, experience cravings, and feel bloated or experience cramps. Training focus here should be autoregulared, allowing athletes to decrease volume or intensity according to their individual responses to the physiological cascade due to hormone release. But if an athlete has mild effects to hinder training, they are encouraged to train with an intensity as high as they can tolerate within the ultimate training scheme.
The role of estrogen cannot be understated, for the health and performance of an endurance female athlete. Estrogen concentrations signal regular menstrual cycle function. Estrogen is released by the hypothalamus in the brain; and the cascade of physiological responses occur to enough caloric intake to support the essential functions that estrogen stimulates. However, if there is a negative caloric balance, and there is a severe caloric deficit - due to training or voluntary caloric suppression (disordered nutrition)- estrogen cannot be released from the hypothalamus. There is not enough energy available for the body to be able to support the menstrual cycle and reproductive functions. Lack of estrogen not only suppresses the menstrual cycle, but also inhibits bone formation and repair.
AHHHH SO MANY QUESTIONS! Hang tight fam, more science to come next week! I will complete the final post with all my references, but the diagram is all credit to ATP Science!