I did 50 leg curls a day for a week — and the results surprised me

a photo of a woman doing leg curls
(Image credit: Shutterstock)

Here on the Tom's Guide fitness desk, there’s nothing we love more than a workout challenge. From trying 50 walking planks a day for a week, to walking 10,000 steps a day for a month, we've tried it all. Next up on my list was hamstring curls, so I decided to add 50 to my routine for a week — read on to find out what happened. 

The simple hamstring leg curl targets the muscles in the back of your thigh, including the semitendinosus, semimembranosus, and biceps femoris, which make up the hamstrings. These muscles work together to allow you to bend at the knee and move your thigh — critical for walking and running. A hamstring curl, or leg curl, is a simple exercise that involves bending your knees and moving your heels toward your glutes while keeping the rest of your body still. It’s typically done on a leg curl machine, but there are a number of alternatives you can do without going to a gym. 

The hamstring curl is a great exercise for runners, but what would 50-a-day do to my legs? I set out to find out. As a reminder, working on the same muscle group every day isn’t recommended as it’s important to give muscles time to recover after putting them under stress. If you’re new to an exercise, or you’re returning to exercise after an injury, it’s a good idea to check your form with a personal trainer before adding reps or weight to the move. 

How to do a leg curl 

As mentioned in the intro, I mainly focused on variations that didn’t involve going to the gym. Here are a few options

an illo of a woman doing a hamstring curl

(Image credit: Shutterstock)

Standing hamstring curl: This is the most simple form of hamstring curl. Stand with your feet hip-width apart, and shift your weight to your left leg. Bend your right knee, bringing your heel up to your right glute, then slowly lower your leg back to your starting position. Complete all the reps on one side before moving on to the opposite leg. 

resistance band hamstring curls

(Image credit: Shutterstock)

Prone hamstring curl: To do a prone hamstring curl, use a long resistance band and loop it around something stable. Lying on your stomach, loop the resistance band around one heel, with your ankle flexed. Pull against the resistance band to lower your heel to your glutes. Pause, then straighten your leg back to your starting position.

a photo of a woman doing hamstring curls

(Image credit: Shutterstock)

Dumbbell hamstring curl: To do a dumbbell hamstring curl, hold a dumbbell in between your feet and curl both feet up toward your glutes, then lower back to your starting position. You can also use a set of the best ankle weights if you don’t have a dumbbell on hand.  

an illo of a man using a leg curl machine

(Image credit: Shutterstock)

Lying leg curl machine: If you do have access to a gym, an easy way to do leg curls is to use the leg curl machine. To do so, start by lying on your stomach on the leg curl machine, extending your legs so the roller pad sits just above your heels. Hold the support handles on either side of the machine. Flex your knees, keeping your hips firmly pressed on the bench, and curl your heels towards your glutes, hold briefly, then extend your legs back to your starting position. 

I did 50 leg curls a day for a week — here’s what happened 

As a runner, strong legs are important when it comes to getting faster and avoiding injury, but after 350 leg curls over a week, here are the lessons learned: 

I realized how lazy my hamstrings and glutes have gotten

Like many runners, I suffer from weak glutes, and I quickly realized how quad-dominant I’d become as a runner on my first 50 leg curls. I opted to add a resistance band and do prone hamstring curls, and I could definitely feel the back of my legs working hard during the move. I also noticed quickly that one leg was a lot stronger than the other — I’m right-handed and tend to lead from my right leg, but doing single-leg hamstring curls really highlighted my left side was weaker. 

If you’re looking for a set of the best resistance bands for training at home, we’ve found them here. You’ll want a long band for this exercise. 

I enjoyed the variety of this exercise

During some of these week-long challenges, I’m sick to death of the exercise by Day Two. The joy of leg curls was the ability to mix things up each day. I grabbed a set of ankle weights and did standing hamstring curls one day, placed a dumbbell between my feet on another, and even used a yoga ball to perform leg curls, resting my feet on the ball and raising my hips and legs off the floor, then rolling the ball into my glutes. Other days I went to the gym to do them on the lying leg curl machine.

Whether you’re at home or in the gym, this is a move that can easily be adjusted or modified. 

Adding resistance and weight upped the ante

I found using resistance bands and the weighted machine at the gym helped increase the load on the hamstrings during this exercise. When using a heavier weight, it’s important to think about pressing your belly button into the mat to avoid arching your back and putting pressure on your spine, or if you're using a machine, keeping your hips pressed into the bench. 

I won’t be doing them every day, but I will be adding them to my leg workouts in the future

By the end of this week, I definitely felt this move in my hamstrings. No physio would recommend hammering the same muscle group every single day, so while I’ll definitely be adding hamstring curls to my leg workouts in the future, I’m looking forward to taking a break for now. 

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Jane McGuire
Fitness editor

Jane McGuire is Tom's Guide's Fitness editor, which means she looks after everything fitness related - from running gear to yoga mats. An avid runner, Jane has tested and reviewed fitness products for the past five years, so knows what to look for when finding a good running watch or a pair of shorts with pockets big enough for your smartphone. When she's not pounding the pavements, you'll find Jane striding round the Surrey Hills, taking far too many photos of her puppy.