How To Tune Up Your Knees

Creaky knees? Strengthen your joints with supine leg lifts to prevent pain and buckling during long descents with heavy loads. Bonus: Your ankles and hips will benefit, too. Perform this circuit with 3- to 5-pound ankle weights.

- Emily Pennington

THE CIRCUIT

Sets 2-3 (parts 1 through 4 on each leg is a set) Reps 10 (each leg); complete 10 of each exercise on the left leg without stopping. Then do the right leg. That's one set. Rest 0 to 90 seconds between sets (decrease as you gain strength)

Part 1 Straight Leg Lift

Strengthen the hip flexors—which help lift your upper leg —while stabilizing deep core muscles to prevent the patella from rotating and causing pain when hiking.

1. Lie on your back and bend your right knee, keeping your right foot on the ground. Extend your left leg on the ground with toes flexed up.

2. Engage your abs and lift your left leg until your knees are in line.