Hamstring Training for Sprinting Speed

Posted: May 11, 2013 in Speed, Training
Tags: , , ,

If you train with me, or you are a regular visitor to this site, you already know that I talk a lot about the importance of hip extension during sprinting. Powerful extension of the hip is what propels runners forward, so my athletes spend a lot of time developing their glutes, which control hip extension. However, one important aspect of our training that I haven’t talked much about yet is hamstring strength. If your hamstring strength isn’t up to snuff, all the glute strength in the world won’t help you run fast.

When sprinting, your goal should be to put as much force into the ground as possible to move forward as quickly as possible. This action is driven by hip extension, but in order for the force generated by the hip to reach the ground, it needs to travel through the hamstrings first. This means that in order to run fast, sprinters need to have strong hamstrings that are capable of absorbing and transmitting huge amounts of force effectively and without injury.

Having a Family Size amount of swagger doesn't hurt either

Having a Family Size amount of swagger doesn’t hurt either

Running is broken up into 2 phases: Stance Phase and Swing Phase. If we’re talking about your right leg, Stance Phase is when your right foot is on the ground, and Swing Phase is when it’s in the air.

swing and stance phases

Studies suggest that hamstring injuries are most likely to occur during the late swing phase or the early stance phase. This is because the forces acting on the hamstrings are highest during these times. During the late swing phase, the hamstrings act to slow down knee extension, and during the early stance phase, the hamstrings contract isometrically to transmit force from the hip into the ground.

Throughout the entirety of the stance phase, the hamstrings need to contract isometrically to resist knee extension and transfer power effectively from the hips to the ground. If the hamstrings are weak, the legs will “leak” energy and less of the force from hip extension will reach the ground, which decreases sprinting speed.

If that’s too dry and scientific for you, think of it this way:

(In this scenario, think of your hand as your glutes, the spaghetti as your hamstrings, and the table as the ground)

Take 3 or 4 pieces of uncooked spaghetti, representing “weak hamstrings” and bend them against a table. The 3 or 4 pieces of spaghetti can only transmit about 1 pound of force into the table. No matter how much force I supply with my hand, they won’t be able to transmit more than 1 pound of force into the table, and will break if I push too hard.

I test all my spaghetti this way to make sure it's worthy of being eaten by me

I test all my spaghetti this way to make sure it’s worthy of being eaten by me.

Now take an entire handful of spaghetti, representing “strong hamstrings” and do the same thing. The larger (stronger) handful is capable of transmitting more force, and is able to resist breaking. Now I can apply much more force to the table through the spaghetti.

Spaghetti: Useful for more than just dinner


So How Do We Train the Hamstrings?

Since the hamstrings only contract eccentrically and isometrically during sprinting, they should be trained primarily eccentrically and isometrically (duh). If you watch sprinters run in slow motion, you can see that once their foot hits the ground, the angle of the knee doesn’t change. Nor should it. So the hamstrings are contracting, but not shortening, which is known as an “isometric contraction”. The knees really don’t bend until the beginning of the Swing Phase, and that is more due to the whip-like action of the leg than to hamstring contraction. Then when the leg swings forward, the hamstrings contract while they are extending (known as an “eccentric contraction”) to keep the knee from fully extending.

Let’s take a look at Usain Bolt to see this in action. Focus on his left leg. Here’s what happens during the Swing Phase:

Knee is bent here...

Knee is bent here…

...now the knee starts to extend...

…now the knee starts to extend…

...now the hamstrings contract to stop the leg from extending and prepare for Foot Strike

…now the hamstrings contract eccentrically to stop the leg from extending and prepare for Foot Strike

Now watch the angle of his knee during the Stance Phase, which is broken up into Foot Strike/Early, Mid, and Late Stance Phase.

Here's his knee angle at Foot Strike...

Here’s his knee angle at Foot Strike…

...here it is at Midstance...

…here it is at Mid Stance…

...and here it is in Late Stance

…and here it is in Late Stance

Pretty much the same exact angle. So clearly, the hamstrings aren’t doing any concentric (shortening) work. If the hamstrings don’t contract concentrically while sprinting, is the Seated Leg Curl an effective method for improving sprint-specific hamstring strength? Nope. To train the hamstrings specifically for running speed, we need exercises that are going to utilize maximal eccentric and isometic contractions.

What You Should Do

For improving isometric hamstring strength, try Bent Knee Hip Thrusts. These can be done with your feet on a bench, or on a Swiss Ball. Try to maintain the angle of your knees by keeping your hamstrings tight through the whole motion. You can add resistance by loading a bar, dumbell, or plate on your lap.


For eccentric strength, try Nordic Curls. When doing these, try to lower yourself to the ground as slowly as possible, which maximizes the eccentric force on the hamstrings. You can do this by securing your feet underneath something, or with a partner holding your feet down, as long as they don’t mind you accidentally farting on them from exertion.


Fair warning, these are both tough exercises. Especially the Nordic Curls. But they are way more beneficial than those seated leg curls you see everyone doing. So if you want to increase your sprinting speed and decrease your risk of hamstring injury, add these two exercises to your program, and subtract Seated Leg Curls.



  1. […] If you’re an athlete looking to improve your running speed, add these exercises to your program if you haven’t already, and be sure to pay more attention to how well you’re training your glutes and hamstrings. And for more information on the role the hamstrings play in sprinting, check out this post as well. […]

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