When it comes to building lower pectorals, triceps and frontal deltoids, dips are without doubt one the best exercises I've ever used. They are seldom used nowadays and the reasons are plain to see: you have to be able to handle your own bodyweight for reps ? unless you have access to one of those fancy-dan machines that allow you to dip (or chin) with less than body weight.
A correctly done dip has two distinct rep-stroke lengths, two levels: drop down until upper arms are parallel to the floor or go all the way down as far as you can. Either depth works the triceps exquisitely, assuming you lockout hard at the top of every rep and hold that flexion for a beat before lower yet again. The parallel tricep dip is a tricep isolation movement with some slight pectoral and front deltoid stimulation.
The full dip is an entirely different animal. In a full dip you lower down as far as humanly possible ? often you will have to actually relax the muscles of the shoulder girdle in order to achieve the maximum low position. When you start to arise in the full dip the chin is kept on the chest and the athlete 'leans into' the dip to trigger the pectoral muscles. At mid-point throw the chin skyward and finish the exercise using the triceps. Again, for maximum tricep stimulation lock the arm out completely and hold the maximum flexion for a full one second count before lowering.
Now a lot of really strong guys can do dips while wearing a belt that allows them to dangle extra poundage ? but in 8 out of 10 cases most use shallow rep strokes and don't lock out at the top. I always advise an athlete to extend the rep range-of-motion instead of adding extra poundage. 2-3 sets to failure are recommended. The perfect session placement for dip inclusion is after chest work and before triceps. As I've stated before there are a myriad of reasons that chest exercise should be followed by tricep exercise and the finest segue from pecs to tris is the dip, preferably the ultra-deep style. The ultra-dip requires pec stimulation to get the body started upward from the low position and requires triceps to finish off the rep stroke.
Here is a tip from the Purposefully Primitive Handbook or old Indian Tricks: start off with a set or two of ultra-dips and as they become impossible due to fatigue, switch to parallel dips so as to keep the party train rolling. Once you are burnt out on dips, start with heavy tricep work such as nose-breakers, standing overhead tricep extensions using a single dumbbell and finish off with cable pushdowns of different varieties. Happy dipping!
Marty Gallagher is a former fitness columnist for washingtonpost.com. He is also a former national and world champion powerlifter. Marty's articles have been featured in Muscle Media, Muscle & Fitness, and Powerlifting USA magazines. His website, http://www.martygallagher.com, assimilates years of accumulated knowledge from the athletic elite and makes them accessible to the common person. The "Purposeful Primitive" way has been proven effective time after time after time for weight loss, increasing muscle tone, and complete physical transformation.