X2 Ab Ripper and Crossfit

I had quite a lot of time today to do an extra workout. So, instead at first I did X2 Ab Ripper, then did some light reps of workouts from P90X Plus Upper Body. After that did a short WOD of Crossfit of 5 rounds of 10 turkish get ups (5 on left, 5 on right), then 100 jump ropes. The WOD seems easy,  but by the time you hit the third round is when you start to feel the tiredness. Glad the WOD wasn't too heavy, it was light. The lighter the WOD, the more rounds needed to feel the burn.