Hack One Leg Calf Raise
- Target muscle
- Gastrocnemius
- Synergist muscles
- Soleus
- Equipment
- Sled machine
- Body part
- Calves
- Type
- Strength
The hack one leg calf raise is a single-leg strength exercise that builds the calves using a hack squat sled machine. It primarily targets the gastrocnemius, with the soleus assisting, and the unilateral setup lets you work each lower leg independently to even out strength and size imbalances.
How to do the Hack One Leg Calf Raise
- 1Load the hack squat sled machine with a light weight and position yourself under the shoulder pads as if setting up for a squat.
- 2Place the ball of your working foot on the lower edge of the platform with your heel hanging off, and either lift the other foot or rest it lightly behind your working leg.
- 3Straighten your legs and disengage the safety stops so the sled is free to move, keeping a slight, soft bend in your knees.
- 4Lower your heel under control toward the floor until you feel a deep stretch through your calf.
- 5Drive through the ball of your foot and rise up onto your toes as high as possible, squeezing the calf at the top.
- 6Pause briefly at the top, then lower with control through a full range of motion.
- 7Complete all reps on one leg, then switch and repeat on the other side.
- 8Re-engage the safety stops and rack the sled before stepping out of the machine.
Form tips
- Use a full range of motion on every rep — a deep stretch at the bottom and a high contraction at the top recruit the gastrocnemius far better than short, bouncy reps.
- Keep your knee close to fully extended to bias the gastrocnemius, since it crosses the knee and works hardest when the leg is straight.
- Control the descent over 2–3 seconds rather than dropping fast, keeping constant tension on the calf.
- Keep your supporting hand on the machine for balance and always set the safety stops before unloading the sled.
Common mistakes
- Bouncing out of the bottom using the Achilles tendon's stretch reflex, which cuts muscular tension and raises injury risk.
- Using a short, partial range of motion, which leaves the calf undertrained through its strongest positions.
- Bending the knee heavily during the rep, which shifts work toward the soleus and away from the targeted gastrocnemius.
- Loading too much weight and rushing the reps, sacrificing the deep stretch and high squeeze that drive growth.
- Forgetting to balance both legs equally, letting the stronger side do more reps and widening the imbalance you set out to fix.
Frequently asked questions
What muscles does the hack one leg calf raise work?
It primarily works the gastrocnemius, the larger calf muscle, with the soleus assisting underneath. Training one leg at a time helps correct side-to-side strength and size differences.
Why train one leg at a time instead of both?
Single-leg work isolates each calf so a dominant side can't compensate, which evens out imbalances and lets you fully overload the working leg without doubling the loaded weight.
How many sets and reps should I do?
Calves respond well to higher reps. Aim for 3–4 sets of 10–15 controlled reps per leg, using a full stretch and squeeze, and add weight gradually as it gets easier.
Should I keep my knee straight or bent?
Keep the knee nearly straight with only a soft bend. A straight leg emphasizes the gastrocnemius, while a deeply bent knee shifts the load onto the soleus.
