Transgender athletes are now allowed to participate in the Olympics without having to undergo sex reassignment surgery, according to new recommendations issued by the International Olympic Committee (IOC).

Female-to-male transgender athletes should be able to take part in male category events ‘without restriction’ under the new guidelines. Male-to-female athletes must use hormone therapy, and will need to show that their testosterone level is below 10 nanomoles per liter at least a year before participating and “throughout the period of desired eligibility to compete in the female category.” In addition, an athlete’s stated female gender identity “cannot be changed, for sporting purposes, for a minimum of four years.”