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If your stiff and sit a lot, you need this exercise! It's a tough one for a lot of people, but the pay off is incredible, especially if you have upper back and neck pain.
Single Arm Reach: shoulders, scapular muscles, spinal erectors, core, glutes, lats, triceps, forearms
Swimmers: spinal erectors, neck, core, shoulders, scapular muscles, butt, hamstrings