Muscles worked
The clamshell is a small movement in which your hip rotates outward while your hips and knees are bent. Your gluteus medius does most of the work, and the small, deep rotators behind the hip joint help, along with your gluteus maximus. The load is low, even with a band, so the exercise is mostly used as a warm-up, as an add-on after heavier leg work, or by people learning to feel the side of their glutes working.
Common mistakes
- The band is too strong from the start. With a tight band your knee moves only a few centimetres. Start with your lightest band, or no band if you are new, and only move up once every rep feels easy.
- You feel it mostly at the front of your hip. This often comes down to your hips being almost straight. Bend your hips so your thighs point diagonally forward and lift your knee a shorter distance.
- You hold your head up with your neck. Your neck tires long before your hip has finished working. Rest your head on your lower arm or on a cushion.
Variations and alternatives
- Seated band abduction works both hips at once and copes with a stronger band.
- The fire hydrant is a step up with no equipment, on all fours, where your trunk has to work too.
- Machine hip abduction takes over when bands are no longer enough, with a weight you can read and increase.
Sets and reps
Two to three sets of 15 to 20 reps per side is a common approach. Hold your knee up for one to two seconds on every rep, and finish one side before you turn over. Before a leg session, one or two light sets are enough as a warm-up. You can read about how many sets suit you in the guide to sets and reps.
Lengthen the pause at the top first, then add reps, and move to a stronger band last. That is progressive overload too. Once you have outgrown your strongest bands, heavier glute exercises will give you more than yet more clamshells. If it hurts in your hip or groin, rather than just feeling tired, stop the exercise and have a doctor or physiotherapist look at it.