EXERCISE · BODYWEIGHT
Bird Dog
CoreBack
Start on all fours with your hands under your shoulders and your knees under your hips. Your spine has one job here: stay flat and still, like there's a glass of water balanced on your lower back that can't spill. Everything that moves is your arms and legs — nothing else. Reach one arm straight forward and the opposite leg straight back at the same time, only as far as you can go while your hips and shoulders stay square to the floor and your lower back doesn't sag or round. If your hips start to rock or twist to help you reach further, you've gone past the range your spine can hold still through. Pause briefly at full extension, then return with control and switch sides.