We’re not just talking about your biceps or your waistline, but your overall strength, flexibility, and resistance to injury. Can you touch your hands together behind your back? Can you reach in front of you while holding a plank? See, even the best workout plans aren’t perfect—they can’t cover everything you need for a balanced, strong, and bulletproof body at once. Invariably, some muscles are neglected, and that creates imbalances. That’s why it’s important to periodically test yourself and assess what needs work.