CHALLENGE of the week: Stability Ball Rack Chins by @msflorendo. Don’t be fooled - it’s much harder than it looks! This is a great exercise to build strength and tone your arms and back while working your core. Body weight exercises are a MUST in your workout regimen - they show you how really strong you are. ✳ HOW TO: (1) Grab a stability ball and get under a Smith Machine rack. (2) Grab the bar overhand (or underhand) and place 1 foot on the ball. When you have your balance, pl