The trainer: Mauro S. Maietta, CPT, district fitness manager at Crunch
Why this move: "Pull-ups and chin-ups target your arms, shoulders, trunk (abdominal muscles), and the latissimus dorsi or lats. The 'lats' are a huge muscle that adds that 'V-taper' athletic shape to your body, which creates a leaner appearance to your midsection and visible muscularity in any shirt. In addition to the aesthetic benefits, the lats are involved in stabilizing the spine and shoulders, which builds injury tolerance. If you lack the capacity for a pull-up, try a lat pull-down variation."
Get the instructions: pull-up