Women are four times more likely than men to hear that dreaded pop and have their ski seasons ruined with a knee injury. And the reason might make you think twice before trying to beat your boyfriend down the bumps.
After conducting a study that focused on more than 100 recreational skiers from Tahoe Basin, Calif., this past ski season, Dr. Stephen Liu of the UCLA Medical Research Center concluded that the Anterior Cruciate Ligament-what keeps the knee stable-is weakened during the first two weeks of the menstrual cycle, when estrogen levels are at their highest. Collagen is a building block of the ligament, and for a reason still unknown to researchers, the production of this fibrous tissue is halted by estrogen. "We found there was a significant difference during an estrogen surge in that it alters the ligament metabolism and is probably what weakens it during that time," Liu says.
This means that certain hormone balancing drugs, such as the birth control pill, may decrease this particular risk. For now, Liu advises that women ski carefully during their two-week danger zone.