abs!

[sk1_dynasty]

http://www.menshealth.com/fitness/best-abs-workout-ever?cm_mmc=YTPG-_-Your%20Workout%20Is%20Horrible-_-Entry-_-best-abs-workout-ever

plank 30 sec, twice
mountain climbers 30 sec, twice
side plank 30 sec, twice each side