Scheduling your training sessions around your period can optimize your workouts and offer some serious results.

There's no tiptoeing around it: Periods can make your workouts a living nightmare and a real, literal pain in the butt-well, more like gut.

It can interfere with your social life and throw off your resolve to eat healthily. But there are also times when the cramps, irritability, and mishaps (Did that squat thruster just make me bleed through my Lulus?) are just too much to handle, so you skip the gym. (Asking for a Friend: Why Does My Tampon Leak When I Squat?)

But now researchers are saying that opting out of your workouts during the first two weeks of your menstrual cycle might mean you're missing out on some serious gains. (Typical menstrual cycles can last from 21 to 35 days, but they always begin at the first sign of your period.) Training during this crucial time period can yield greater power, strength, and muscle mass than any other time of the month, according to a new study from Umeå University in Sweden.

These findings were not actually what researchers set out to discover. They were initially interested, partly, in nailing down the best training schedule for women that wouldn't increase their workload or cause overreaching or overtraining syndrome, which both can lead to abnormal menstrual cycles. But the final results showed some unexpected and enlightening differences when it comes to training during your period.

For the study, 59 women (some of whom were taking oral contraceptives) participated in a four-month program to assess resistance training's influence on muscle mass, strength, and power. Everyone performed lower-body workouts five days a week for a two-week period during their cycles (either the first two weeks, or the last), and also another leg workout once a week for the remainder of the month. A control group performed similar leg resistance training three times a week throughout the month. (Read up on the different stages of your menstrual cycle with this easy-to-follow guide from NYU's School of Medicine.)

Results showed that the women who worked out during the first two weeks of their cycle saw a considerable boost in jump height and in the max power output (meaning speed and strength combined) of their hamstrings. They also increased the lean body mass in their legs.

As for the women who trained during the second half of their cycle (when PMS peaks)? These ladies didn't see these same improvements. People in the control group who trained consistently throughout the month did see an increase in jump height, but gains in muscle force and flexibility were only observed in their left hamstring. No signs of overtraining were found in any group.

Previous research on how your menstrual cycle affects your performance has been a bit conflicting and varied (see: What Your Period Means for Your Workout Schedule). So while it's not guaranteed that you'd see the same results, it is a point in favor of stopping by your favorite barre studio even when you're on your period and you kinda don't want to. And while this isn't a green light to only work out during certain weeks of the month, it can help clue you in on how to best plan your workouts.

Still don't love the idea of working out on your period? Check out 6 Ways to Stop Your Menstrual Cycle from Ruining Your Workouts.