Moderate-intensity classes that leave women feeling smashed raise cortisol without producing the post-exercise growth hormone and testosterone response that would dampen it.

it puts women squarely in moderate intensity where they're so used to leaving one of those classes feeling absolutely smashed that when you tell them actually that training doesn't work for you because it's putting you in a state of intensity that drives cortisol up but it's not a strong enough stress to invoke the post exercise growth hormone and testosterone responses that we want to dampen that cortisol