Wednesday, April 12, 2006

Interesting Article : The Sexes vs. Altitude

This is taken from www.bodyresults.com :

Women's Fuel Usage At Altitude Vs. Men
Braum, B., Butterfield, G. E., Mawson, J. T., Muza, S., Dominick, B. S., Rock, P. B., & Moore, L. G. (1997). “Women at altitude: Substrate oxidation during steady-state exercise at sea level and after acclimatization to 4300 meters elevation.” Medicine and Science in Sports and Exercise, 29(5), Supplement abstract 784.
This study looked at sixteen women over a period of 12 days who were in either the follicular (pre-ovulation) or luteal (pre-menstrual) phases of their menstrual cycles at sea level and again at Pike’s Peak (14,109’). The ovarian hormones progesterone and estrogen may cause women to acclimatize to high altitude differently than men, and variations in both hormones in the follicular and luteal phases of the cycle may alter the responses. After acclimatization to high altitude, weight-stable men tend to use more carbohydrate as an exercise fuel compared with at sea level. Women, on the other hand, oxidize less carbohydrate and more fat at 14,109’ compared to utilization at sea level. This is one more study that shows consideration of the peculiar female response to exercise and altitude is warranted. Treating women with the identical training and adaptation principles as men is an erroneous coaching strategy.
Take-home message:
Along with the research discussed and summarized in our high-altitude nutrition article at
www.bodyresults.com/E2HighAltitudeNutrition.asp, this research seems to point to another reason why women, who naturally have more bodyfat to begin with, may do better at altitude than men. When fueling your own alpine excursions, carefully note what works best for you in terms of macronutrient ratios (carbohydrates-protein-fat) and compare that with the ratios you prefer (for maximal energy) at sea level. If you tend to have trouble at altitude, simply changing your nutrition strategy can provide relief. While a registered dietitian, nutritionist, or male friend might be able to suggest foods that should be good fuel sources, only you will know what works best for you during particular phases of your cycle.

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