Power Snatch: Lot's of bending at the waste. The easier we can get into a proper starting snatch position, the less energy we'll waste. The tighter your hips are, the harder your lower back is going to work. This can be pretty uncomfortable doing power snatches for 10 minutes. Give these exercises a shot before you perform and see if you can notice any difference.
Recovery:Your calves are going to be taking a pounding on this one. Even more the less proficient you are at double unders. Jumping high and slamming into the ground during attempts will take its toll. Be sure to treat your calves right once it's all said and done. Use a massaging stick or foam roller and unglue tight areas. Allow for blood flow to get to the damaged areas and help speed up your recovery time.
Hope this helps and good luck!