Injuries, Recovery and Jumping on Horses

My legs were unusually fatigued the day after my singlet workout of 100 box jumps last week. I tweaked my left hamstring while getting up out of a chair the next morning. I walked funny for a few days and couldn't run for a couple more. I did no workouts while I let my leg recover. Today, I got back on that horse.

Sean's WOD
500 single unders (simple jump rope)
25 box jumps (24" box)

11:13

splits
 1:50 150 SU (150)
 2:59  50 SU (200)
 3:53  50 SU (250)
 4:36  50 SU (300)
 5:24  50 SU (350)
 6:15  50 SU (400)
 7:01  50 SU (450)
 8:00  50 SU (500)
 9:27  10 BJ (10)
10:20  10 BJ (20)
11:13   5 BJ (25)

I've yet to complete more than 71 single unders in a row without missing. During the 500, I would usually rest just long enough to record the time and figure out how many I had to go. Towards the end of the single unders I needed to jump higher and higher just to complete revolutions without missing. In the last set of 50, I probably missed 10+ times.

I rested from 8:00 to 9:00 before starting the box jumps then dug in. The 4" increase in heigh from before seems huge. Since this is an explosive motion, giving no extra time to get the same energy, I think it probably takes a lot more power than the 20" jumps. I really wanted to finish the box jumps in 2 sets but after 10 I wasn't sure I could make it to the top of the box and didn't want to hurt myself again on my first workout. I started each set of box jumps on the 1 minute increments. Eventually, I hope to do more than 5-10 of these at a time and to cut my rests down a lot more.