Many people don't now that having weak glute muscles and hip abducters can lead to lower body injuries and changes in gait. So next time you're in the gym don't just work on your squat to look better at the beach, but also for a better overall quality of life. Lifestyle factor that lead to weak glute muscles, and glute medius more specifically are, sleeping on your side and flexing and adducting your top leg over your bottom leg. Standing predominantly with all of your body weight on one leg can cause the pelvis to move sideways and the hip joint to adduct; contributing to weak hip adductors. Ilitiobial band (ITB) syndrome, which is quite common can result from weak gluteus medius. Being unable to control thigh abduction and external rotation can place greater tension on the tensor fascia and ITB. Gluteus medius dysfunction can also contribute to patellofemoral pain syndrome, which results in decreased hip control and increased femoral adduction and internal rotation.
The following exercises can help with the aforementioned conditions. Before starting any exercise routine make sure to consult your doctor.
Side Lying Clams
Starting Position
Ending Position. Hold for 3 seconds and slowly return to starting position.
Squats
Starting Position
Ending Position. Make sure to keep back straight and go as far down as possible.
Sidestepping
Starting Position
Ending position. Take a step to the side as far as possible and return to starting position. Repeat on opposite side.
Single Leg Sit Up/Down
Starting Position. Begin seated.
Ending Position. Stand up on one leg slowly, and then slowly return to a seated position. Repeat on other leg.
Single Leg Step Up/Down
Starting Position.

Ending Position. Slowly climb up on one leg and slowly return down to starting position.
Reference: Glute Medius & Hip Abduction Functional Training, www.dynamicchiropractic.com