Everyone wants bigger hammies, right? Right. Chyna Cho has the answer with this hamstring-blasting (plus glutes!) exercise: glute hamstring raises. Situate yourself in the GHD machine facing the ground. Starting upright, slowly lower yourself down, and then using your backside, pull yourself back up again, like so.

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A word of warning: these are no joke. Even if you regularly do other hamstring exercises, these are a different monster. Start small, doing just the negative (the part when you’re moving downward).

If that’s still too challenging, scale further. You can do this by sticking your butt out and pushing your shoulders forward, so your body sort of “accordions.” This will, in a sense, lessen the load you’re trying to lower and lift. Happy training!

Main image: Chyna Cho/Instagram