The dip is an exercise used in strength training. Normal, shoulder-width dips primarily train the triceps, with major synergists being the anterior deltoid, the pectoralis muscles (sternal, clavicular, and minor), and the rhomboid muscles of the back (in that order). Wide arm training places additional emphasis on the pectoral muscles, similar in respect to the way a wide grip bench press would focus more on the pectorals and less on the triceps.
Performing the Exercise
To perform a dip, the exerciser hangs from a dip bar with his arms straight and shoulders over his hands, then lowers his body until his arms are bent to a 90 degree angle, and then lifts his body up, returning to the starting position. Usually dips are done on a dip bar, with the exerciser's hands supporting his entire body weight as pictured.