Pull - ups with the bar touching the chest on the curved horizontal bar, with the widest grip possible, 30 repetitions. (fitnessandpower.com)
Lightly touch your chest, then quickly press the dumbbells straight up and slightly in until your elbows are just short of locked out. (bodybuilding-wizard.com)
If their spine curves more that normal you risk their chin touching their chest. (mommystroller.com)