Women don't often have an advantage over men when it comes to strength. But according to science, they have a leg up on the day after a hard workout: women don't experience as much post-exercise soreness as men do. Delayed-onset muscle soreness, or DOMS, is the pain and stiffness that starts 6–12 hours and peaks 24–36 hours after exercise. It's especially common after workouts that involve what are known as "eccentric contractions," where a muscle is both flexing and lengthening, as in the lowering phase of a bicep curl. Though a common misconception about DOMS is that it's caused by a buildup of lactic acid, modern science recognizes that the pain probably stems from inflammation and other reactions to microtears in the muscle tissue.
It's there that scientists think women, with their abundance of estrogen, have the advantage. Animal studies point to a difference in those microtears: male rats show more muscle damage than female rats after eccentric contractions, for example. But studies of humans show something further down the chain. A study in the Journal of Applied Physiology found that men and women experienced the same amount of muscle damage, but men's muscles had more inflammation post-exercise. Though more study is needed to learn exactly why women feel less pain from their gain, it could explain why they have an advantage over men in intense endurance events like ultramarathons. Learn more about the science of exercise with the videos below.