Leg curls are a frequently used exercise to train the hamstrings, yet calf cramps are commonplace for many lifters.
So, why do you get a calf cramp leg curling? The number one reason your calf can cramp during the leg curl is if you let your toes point down vs up. The chances of the calf cramping are also increased when you are dehydrated, low on electrolytes, or holding a foot position for extended periods of time, such as higher rep sets.
In this article, I will cover…
- Whether the calf cramping in the leg curl is good or bad
- Why it happens
- How to stop it from happening in future
Is Your Calf Cramping In The Leg Curl Good or Bad? Should You Be Concerned?
While occasional cramps do not merit a direct concern, they are clearly uncomfortable and can take away from your training.
Persistent cramping, however, can be indicative of other issues and should be raised with a medical professional.
Related article: Should powerlifters train calves (3 expert opinions).
Why Do Your Calves Cramp During Leg Curls (4 Reasons)
The 4 reasons why calves cramp in the leg curl are:
- The Calf Is Active During The Leg Curl
- You Have Held Your Foot Position For Too Long
- You Are Dehydrated
- You Are Low On Electrolytes
1. The Calf Is Active During The Leg Curl
The gastrocnemius is one of two muscles in the calf.
While it primarily functions as a plantar flexor of the ankle joint (pointing the foot downwards) , the muscle also crosses the knee joint and acts as a knee flexor (which is the action of bending the knee towards the butt during a leg curl).
The leg curl isolates the knee flexors in a way not replicated within other movements. Therefore, the gastrocnemius may just not be used to the stress that’s being placed on it, making it prone to cramping.
If this is the case, I recommend just simply dropping the weight and using a load that doesn’t cause the gastrocnemius to be so active throughout the movement — at least until it adapts to the new exercise.
Want a breakdown between the Leg Curl and Leg Extension? Check out my other article on the Leg Curl vs Leg Extension: Pros, Cons, Differences.
2. You Have Held Your Foot Position For Too Long
Calf cramps can be caused by holding a certain position for too long.
During higher rep sets you may be holding your position for over a minute. This is the case if you’re doing 20+ reps, or if you’re implementing tempo training where you’re purposely trying to slow down the movement.
The position you want to avoid for too long is where the ankle is “plantarflexed”. In other words, where the foot is flexed downward where you’re pointing your toe away from you. I find my calf can cramp quite easily during leg curls in this position.
To combat this, I really try and focus on flexing my toes up, and trying to point my toes toward the shin. So long as I keep this position throughout the set of leg curls, my calf is less likely to cramp up.
3. You Are Dehydrated
A common explanation for cramps of all kinds – you are dehydrated.
This is where your body loses more fluid than you take in.
If you are not drinking enough prior to training or excessively sweating throughout your session prior to leg curls this will contribute to your calves cramping.
Another common symptom of being dehydrated is feeling light-headed. I wrote an entire article on this called Why People Pass Out From Deadlifts.
If you don’t feel light-headed, and you have good hydration practices, then your calf is likely cramping for other reasons.
4. You Are Low On Electrolytes
Electrolytes also play a role in preventing calf cramps as they help regulate your hydration levels.
When you sweat you are losing electrolytes from your body, namely magnesium, potassium and sodium.
Particularly relevant as many will have leg curls towards the end of a leg day after several other exercises.
If you are sweating a lot prior to doing your leg curls and having that drop in electrolytes, you will be at an increased risk of calf cramps.
If you feel like you aren’t entering your workouts with enough electrolytes, you could try having a pre-workout meal that is high in electrolytes (my recommendations are below).
How Do You Stop Your Calves From Cramping In The Leg Curl? (4 Tips)
My four tips for preventing your calves from cramping in the leg curl are:
- Stretch Your Calves Before You Do Leg Curls
- Dorsiflex Your Ankles
- Drink More Before Training
- Supplement With Electrolytes
Stretch Your Calves Before You Do Leg Curls
Stretching your calves can help prevent cramping during the leg curl.
The cramp usually occurs at the top of the range of motion, due to the gastrocnemius’s contribution to knee flexion.
Due to this you should look to stretch your calves with a flexed knee.
This can be done using a lunging calf stretch.
For other mobility ideas check out my article on How To Increase Ankle Mobility, which discusses a lot of calf stretches.
Dorsiflex Your Ankles
Dorsiflexion is the flexion of the foot at the ankle to point your toes upwards.
If you have not considered the position of your feet in the leg curl before this can help reduce the chances of cramp, while also improving the recruitment of the hamstrings.
This position helps activate the hamstrings and lessens the stress upon the calves reducing the chances of cramps.
As soon as you lose this ‘dorsiflexed’ position, you risk having your calf cramping.
Drink More Before Training
Ensuring you are adequately hydrated is one of the easiest ways to reduce the likelihood of cramps and may even improve your overall performance in the gym.
Recommendations for training are that you should drink 200ml-350ml of fluid 15-30 minutes prior.
During training you should aim to drink another 100ml-250ml at 15-20 minute intervals.
Supplement With Electrolytes
Supplementing with electrolytes prior to training or having an electrolyte drink throughout your session can help replace those lost via sweat.
This could also be addressed by adjusting your diet.
Eating foods rich in electrolytes such as bananas and sweet potatoes, or saltier foods for sodium.
What To Do If Your Calves Are Still Cramping After Implementing These Tips?
Use An Alternative Exercise
If you’re having persistent issues with cramping during the leg curl, these are the 3 alternative exercises I recommend:
- Romanian Deadlifts: These are a personal favourite of mine to train the hamstrings. They allow for great load progression over time and have good carry over the conventional deadlift as well.
- Glute Hamstring Raises: If your gym has a GHR machine available these are a fantastic option as they train the hamstring as a knee flexor similar to a leg curl.
- Other Leg Curl Variations: Seated leg curls can cause my calves to cramp, but I am always fine on a lying leg curl. Trial the opposite machine to the one you are having issues with. Beyond this you could set up a leg curl with a band or dumbbell. The differing constraints allow for differing positions to avoid aggravating your calves.
Wondering whether hamstrings improve deadlifting performance? Check out my article: Do Leg Curls Improve Deadlifts
Get A Massage
Tight muscles under excessive tension are more likely to cramp.
A massage can help relieve the stress from your calves and reduce the tension they are under.
This in turn reduces the chances of cramping in the following sessions.
Frequently Asked Questions
Do Leg Curls Work The Calves?
The leg curl does work the calves. The calf crosses the knee joint and contributes to knee flexion alongside the hamstrings. However, direct calf training should still be performed and prioritized for your calf development, as it’s only a secondary muscle in the leg curl.
Want to train your calves using BFR bands? Check out my article on Blood Flow Restriction Training For Calves.
The calf cramps during the leg curl because the gastrocnemius functions as a knee flexor as well as an ankle flexor. The chances of cramping are increased when you are dehydrated, low on electrolytes or holding a foot position for extended periods of time, such as higher rep sets.
The chances of cramping can be reduced by stretching the calf prior to training, dorsiflexing the ankle during the exercise and ensuring you are adequately hydrated and have had sufficient electrolytes prior to training.
If the cramping is persistent, trial other hamstring exercises, get a massage or seek medical advice.
About The Author
Jacob Wymer is a powerlifting coach and PhD Candidate in Biomechanics and Strength and Conditioning, researching the application of barbell velocity measurements to powerlifting. He is involved in powerlifting across the board, from athlete to meet director. Jacob runs his coaching services at EST Barbell. You can also connect with him on Instagram.