M4:D41 (D341) Increase Intensity With Twenty-one’s

21's refers to the number of repetitions you will do in a set.  The unique part about 21's is that you break the movement into 3 sets done consecutively.  The break down includes partial range of motion within the full range of motion.  You will use moderate weight when doing 21's. 

Step up to a nice set of dumbbells to do curls.  Do seven partial reps from the starting point to midway through the motion.  Now do seven partial reps from midway through the motion to the end of the motion.  Finally, do seven repetitions through the full range of motion.

This technique will really blast whatever muscle group you use it on.  I get a massive pump in my biceps when using 21's on bicep exercises.  I've used it for my back as well as my legs.  It is always an extremely intense workout when 21's are thrown in.