What muscles does step aerobics work?

Step aerobics is a cardiovascular class rather than a lifting session. But the movement it repeats is a loaded one, and it is worth knowing which muscles are doing it.

What follows is the basic mechanics of a step up and a step down. It is general information about how the movement works, not a promise about what will happen to your body.

The step up

Raising your body onto a platform means extending the hip and the knee of the lead leg against your own body weight. The muscles doing that:

• Gluteus maximus — extends the hip. Anatomy references single out walking upstairs as one of the activities that actually calls on it, which is a fair description of what a step-up is. The largest contributor here, and more so as the deck gets higher.
• Quadriceps — extend the knee.
• Hamstrings — assist hip extension and help control the knee.
• Calves — gastrocnemius and soleus, driving the push-off and controlling the ankle.

The step down

Lowering under control is eccentric work: the same muscles lengthening while resisting. The quadriceps and glutes take most of it. Eccentric loading is a normal part of walking down stairs, and it is a large part of why legs feel a step class the following day.

Sideways, and turning

Step choreography does not only go up and down. Straddles, lateral steps, turns and direction changes bring in the muscles that stabilise the hip side to side:

• Gluteus medius and minimus — abduct the hip and keep the pelvis level while you are on one leg.
• Adductors — the inner thigh, drawing the leg back toward the midline.
• Hip flexors — lifting the knee in knee-lift patterns.

The trunk

Nothing in a step class is an abdominal exercise. But standing on one leg on a raised deck, turning and changing direction asks the trunk to resist rotation and keep you upright. The abdominals, obliques and spinal erectors work as stabilisers throughout — continuously, at low intensity, for most of 55 minutes.

Arms and shoulders

Arm patterns get layered on once the feet handle themselves. With no weights involved, that is low-load shoulder and upper-back work. It raises the effort and the heart rate more than it builds anything. Treat the arms as part of the cardio rather than as a shoulder session.

Two honest gaps

There is no heavy loading, so this is not a substitute for strength training if maximal strength is what you are after. And there is almost no pulling — no rows, no pull-downs — so the back gets stabilising work rather than pulling work.

A step class is a cardio class that happens to work the lower body hard. That is the accurate description of it, and it is a good one.

Where the height comes in

Platform height changes the range of motion, and therefore how much work the hip and knee do per repetition. Higher deck, more work per step, identical choreography. It is the one variable you control directly, it is yours to set, and it can be zero. More on why the deck changes the class.

Is this class for you?

This is an impact class — you'll be stepping up and down on a platform for most of 55 minutes. If you have knee, hip, or ankle issues, check with your doctor first. The platform is optional, and the choreography works without it.

55 minutes, $19.95, platforms supplied, at Casa 21 in Tampa.