PROVO, Utah (ABC4) — Women are sometimes excluded from exercise studies, usually, due to their menstrual cycles. Brigham Young University released a new study this week that shows why they think that methodology is misguided.

The study published in the Journal of Applied Physiology analyzed women’s exercise performance across menstrual cycles and discovered: women’s performance was just as consistent as men’s. However, exercise advice being given to women is usually based on studies done using only men.

The study consisted of seven women and 10 men who completed intense cycling sessions. The men were studied in ten-day intervals, and the women at three points during the menstrual cycle as confirmed through blood draws and ovulation tests. As the participants exercised, researchers measured heart and respiratory rates to assess participants’ performance through five different intensities.

Even though women’s performance is consistent, females were significantly under-represented across studies, as shown in a review by Joe Costello, an exercise physiologist at the University of Portsmouth in England. Data was extracted from 1,382 articles involving a total of 6,076,580 participants, and only 39% of participants were female, with the other 61% being male.

With such a low percentage of exercise participants being female, how does this affect overall data released on exercise? Exercise advice may not be as accurate for women, since the advice is based on studies primarily done on men.

And according to the new BYU study, there are key differences between the sexes and exercise.

The study found sex differences in the power-duration relationship existed. Women reached exhaustion from muscle fatigue about 18% faster than men, even after adjusting for body composition.

“Therefore, previous studies describing the physiology of exercise performance in male subjects may not perfectly describe that of female subjects.” The study said.

You can read BYU’s entire study on their site.