Dumbbell Alternating Bicep Curl with Leg Raised on Exercise Ball
- Target muscle
- —
- Equipment
- Dumbbell
- Body part
- Upper Arms
- Type
- Strength
The dumbbell alternating bicep curl with leg raised on an exercise ball trains the upper arms — chiefly the biceps brachii, with the brachialis, brachioradialis, and forearm flexors assisting — while you sit on a stability ball with one leg lifted. Curling one arm at a time on an unstable base recruits the core and stabilizers, making it a balance-and-strength challenge rather than a pure mass builder.
How to do the Dumbbell Alternating Bicep Curl with Leg Raised on Exercise Ball
- 1Sit tall on the exercise ball with your feet flat and hip-width apart, holding a dumbbell in each hand with arms hanging at your sides and palms facing in.
- 2Brace your core and find your balance on the ball, keeping your chest up and shoulders back.
- 3Lift one foot a few inches off the floor and extend that leg slightly forward, holding it there to challenge your stability.
- 4Keeping your upper arms pinned to your sides, curl the dumbbell in one hand upward while rotating your palm to face your shoulder (supination).
- 5Squeeze the biceps at the top, then lower the dumbbell under control back to the starting position.
- 6Repeat the curl with the opposite arm, alternating sides while holding the raised-leg position.
- 7Complete your reps, lower the raised leg, then switch legs and repeat for an even number of sets.
Form tips
- Move slowly and deliberately — speed here mostly costs you balance, so prioritize control over heavy weight.
- Keep your torso upright and still; let only your forearm move so the biceps does the work and the ball does not roll.
- Fully supinate (rotate the palm up) near the top of each curl to maximize biceps engagement.
- Start lighter than you would for a standing curl until you are confident balancing on the ball with a leg raised.
Common mistakes
- Swinging the torso or rocking on the ball to heave the weight up, which shifts work off the biceps and risks losing your balance.
- Letting the upper arms drift forward, turning the curl into a partial front raise and reducing biceps tension.
- Using too much weight, which forces compensations and makes the unstable seated position unsafe.
- Dropping the dumbbell quickly instead of lowering it, skipping the eccentric where much of the muscle-building tension lives.
Frequently asked questions
What muscles does this exercise work?
It mainly works the biceps brachii in the upper arm, with the brachialis, brachioradialis, and forearm flexors assisting. Sitting on the ball with one leg raised also recruits your core and stabilizer muscles to keep you balanced.
Why curl one arm at a time on an exercise ball?
Alternating arms lets you focus on each biceps individually, while the unstable ball and raised leg add a core and balance challenge. It is more about control and stability than lifting maximum weight.
Is this a good exercise for beginners?
The curl itself is beginner-friendly, but balancing on a ball with a raised leg is not. New lifters should master a standing or seated dumbbell curl first, then add the ball and leg raise with light weights.
What is a simpler alternative if I keep losing my balance?
Try a standard seated or standing dumbbell alternating bicep curl with both feet planted. Once your strength and balance improve, progress back to the exercise ball with a raised leg.
