Despite more women entering high performance sport, up until the 1980s, sport science research was based on 18 to 22-year-old men, with no recognition of the influences and differences between men and women. It’s no secret women have menstrual cycles. During this cycle, estrogen and progesterone go from low levels (low phase) to elevated levels (high phase) before dropping again; this drop is what causes a woman’s menstrual cycle. Not just reproductive hormones, estrogen and progesterone impact many systems of the body: from fluid regulation to metabolism, to maintaining core body temperature and blood pressure control.
During the high hormone phase, women have a greater capacity for burning fat and sparing glycogen, both in the liver and muscle. During this phase, research has found women should stay on top of their carbohydrate intake during exercise. An option during this high hormone phase is using glucose tablets before each high intensity interval. Whilst in the high hormone phase, women have a higher level of progesterone, which causes catabolic effects in the muscles. It is recommended women consume protein and leucine within 30 minutes of ceasing activity. Additionally during this phase women experience a loss of blood plasma of up to 8%, and are not as effective as cooling during exercise (run hotter). It is suggested to add more ice or drink cooler liquids during this time.
During low hormone phases, when compared to her age-matched male counterpart, a woman can afford to reduce her carbohydrate intake. In the low hormone phase, is the time the women most closely resembles a man. Throughout the first week of the low hormone phase women are most likely to feel stronger, fitter and reach their personal bests.
So Women are NOT small men……This is the message exercise physiologist and nutrition scientist Dr Stacey Sims is trying to portray to our female athletes. Based out of University of Waikato Adams Centre for High Performance sport in Tauranga, she helps develop nutrition and recovery programs especially for women. For more information listen to this podcast from Dr Stacey Sims herself:
