Simple side raises that build hip strength.
Keep the top leg straight and lead with the heel to hit the side glute.
Raising a straight top leg from a side-lying position isolates the abductors, the outer-hip muscles that pull the leg away from your body. Leading with the heel keeps the work in the side of the hip rather than letting the thigh roll forward and take over. It looks easy, but done slowly with a controlled lower, it builds the hip strength that keeps knees tracking well in squats and lunges.
The hip abductors along the outside of your hip. They are what lift the leg sideways, and they matter for keeping your knees stable during squats, lunges, and running.
Leading with the heel keeps the leg slightly rotated so the outer hip does the lifting. If your toes point up and the leg rolls forward, the front of the thigh starts helping and the abductors get less.
Slow the lowering phase, add a pause at the top, or increase reps first. After that, ankle weights or a small loop band above the knees are the natural next step.
