Higher testosterone levels may improve athletic performance in women
The test revealed that those given the hormone performed better during aerobic performances, they found no significant difference between the two groups during anaerobic tasks
There's a looming debate in sports circle whether women with high testosterone levels -- a male hormone known to control strength and muscle mass -- have an edge while competing against other women with normal levels of the hormone.
Addressing this, scientists from Sweden's Karolinska Institutet have provide evidence that an increase in the hormone aids athletic performance among young, physically active women.
The study is bad news for South African Olympic winner Caster Semenya, who, in July, was barred from competing at the World Championships in Doha by the International Association of Athletics Federations( IAAF). The federation's new rule stipulates that athletes like Semenya take testosterone-reducing medications.
Elite female athletes with testosterone levels in the male range, as a result of rare inborn conditions, had around 140 times higher testosterone levels than the general population, according to a press statement.
They add that the IAAF requires that female athletes must lower the hormone levels to below 5 nmol/l of blood to be eligible to compete at international level in middle distance races -- 400 m to 1 mile. This move was largely criticized for many reasons, one of which was due to the lack of concrete scientific evidence.
To gain insights into testosterone's role in athletic performance, the team headed by Angelica Linden Hirschberg, recruited 48 young, physically active women, aged between 18 and 35. These women were separated into two test groups. While one half received 10 mg of testosterone cream, the remaining were given inactive substances or placebo, everyday for ten weeks. They were later checked for changes in hormone levels during aerobic activities such as running on treadmills and during anaerobic athletic activities for muscle strength and leg power. Scientists also tracked changes in body fat and lean muscle mass.
Administering the hormone did affect the average circulating levels of testosterone, the study finds. "The hormone rose from 0.9 nmol/litre of blood to 4.3 nmol/l among the women given the hormone cream. No increase occurred in the group given the inactive cream," said the press release.
While the test revealed that those given the hormone performed better during aerobic performances, they found no significant difference between the two groups during anaerobic tasks.
After 10 weeks, scientists tested for changes in weight and body composition. Both the groups, according to the study, showed no changes in weight. "But women given the testosterone cream had much larger changes in lean muscle mass than those given the inactive cream: 923 g vs 135 g, overall; and in their legs, 398 g vs 91 g," read the press statement.
Though the study paints a definitive picture on the hormone's impact on athletic performance, the team of researchers pointed out a few limitations in the study, one of which was the fact that the team couldn't test elite athletes. The team also thought that their study was small: it was carried out in a short 10-week-period.
"Our results are therefore of great importance for the ongoing discussion of whether it is fair to allow athletes with naturally high testosterone to compete in the female category without reducing their hormonal concentration to the female range," the study concludes.
It was published online in the British Journal of Sports Medicine.