Let’s get one thing straight: A HUGE problem exists in nutrition research: Scientists don’t like using women in their research studies because it’s more difficult.
The reason? It is much more difficult to determine whether a particular nutritional intervention is having an actual effect or whether the observed effect is a function of hormonal fluctuations.
This obstacle has had a profound ripple effect in the nutritional recommendations made in the public sphere. The research is coming from a predominantly male population, and the typical recommendations of this research make the completely mistaken assumption that women are just little men.
Good news, some researchers realized the mistake and started to redo the old stuff. Not surprisingly, women react quite differently from men.
Recent literature suggests that key supplements have been shown to be particularly beneficial for women. A basic overview of the menstrual cycle can be helpful in understanding some of the physiological patterns at play.
The menstrual cycle can be divided into three phases: the early follicular phase, the late follicular phase and the luteal phase.1
The early follicular phase is the onset of menstruation and is characterized by hormones at their lowest levels. This phase usually lasts about five days.
The late follicular phase is characterized by an increase in the various hormone levels (estrogen, follicle stimulating hormone and luteinizing hormone) and lasts until approximately day 14. The rise in hormones causes ovulation.
The luteal phase begins after ovulation. Luteinizing hormone and follicle stimulating hormone return to normal levels, while estrogen and progesterone continue to rise to prepare the body for possible pregnancy. If there is no pregnancy, hormone levels return to normal and menstruation begins.
The different phases correspond to unique metabolic changes. Related to this discussion, the follicular phase corresponds to increased carbohydrate oxidation rates, while the luteal phase corresponds to increased core protein oxidation rates and body temperature. Again, knowing these phases can play an important role in the development of effective products for female athletes.
Core body temperature is elevated in females during the luteal phase. As such, the onset of sweating occurs earlier and an increased risk of overheating occurs.2,3,4 Fluids become more and more important during periods of exercise, and women should be very careful that their hydration habits are in line with sports nutrition guidelines.
As a general rule of thumb, females should consume half of their body weight (in pounds) in fluid ounces per day and add sweat loss. For example, a 140 pound woman should consume 70 oz. of water per day at least.
During the follicular phase, the oxidation of carbohydrates is higher. This phase is perfect for glycolytic exercises (like high intensity circuits) that burn a lot of carbohydrates. Carbohydrate supplements can be helpful during this time if carbohydrate needs are not being met otherwise.5
Editor’s Note: The full version of this article, including more advice on supplement ingredients ranging from protein and omega-3s to creatine, caffeine, vitamins and minerals, among others, appears in the digital magazine “Natural solutions for women’s health at every step”. Click on the link to access it and select “Nurturing the Unique Phases of the Female Athlete” from the table of contents.
Casey Thomas, RDN, owns Gamer Diet and works as a performance dietitian, writer, and instructor. His unique research experience has enabled him to implement protocols that have facilitated significant improvements in body composition, health and performance in athletes. Thomas has consulted with professional athletes and Olympians, esports programs, universities and businesses looking to improve their performance. Currently, he is focused on esports, working to bring high-level, research-backed performance nutrition to the gaming world.
1 Wohlgemuth KJ et al. “Gender Differences and Considerations for Women’s Specific Nutrition Strategies: A Narrative Review. ” J Int Soc Sports Nutr. 2021; 18(27).
2 Pivarnik JM et al. “The phase of the menstrual cycle affects temperature regulation during endurance exercise.” J Appl Physiol. 1992; 72 (2): 543-548.
3 Grucza R et al. “Influence of the menstrual cycle and oral contraceptives on thermoregulatory responses to exercise in young women. »Eur J Appl Physiol Occup Physiol. 1993; 67 (3): 279-285.
4 Inoue Y et al. “Gender and menstrual cycle differences in skin sweating and blood flow in response to passive heat exposure. »Eur J Appl Physiol. 2005; 94: 323-332.
5 Oosthuyse T and Bosch AN. The effect of the menstrual cycle on exercise metabolism: implications for exercise performance in women with eumenorrheic disease. »Med. Athletic. 2010; 40: 207-227.