Hamstring strains are extremely common in athletes. It accounts for over a third of muscular injuries in professional athletes, and can have almost a 60% recurrence rate. (3)

Those stats are gross.

There’s so much information on hamstring injuries, yet they keep happening. Why?!

It may be that players aren’t using certain preventative strategies frequently enough or well enough.

This could be an education gap between research and coaches, parents, and players. But, by reading this piece, you’re closing that gap!

About the Hamstrings

Your hamstrings are made of 3 muscles: the biceps femoris, semitendinosus, and semimembranosus.

Together, these muscles bend your knee. The biceps femoris muscle is longer than the rest, so it also crosses your hip joint. It has the added responsibility of extending your leg.

How Do Hamstring Strains Happen?

Your hamstrings undergo the most demand when running and sprinting. During a sprint stride, your biceps femoris stretches at the hip and knee as your leg advances. At that maximally-stretched position, the muscle contracts to slow your leg’s advancement before it contacts the ground. (3)

Maximum stretch + muscle contraction = potential for strain

This is why the biceps femoris is the most strained hamstring muscle, and also why both weakness and inflexibility are contributing factors a strain. (5)

If you don’t have enough strength at the hamstring’s longest position, you have a recipe for muscle strain while sprinting.

With many injuries, high training volumes could contribute to risk. That means high reps, loads, and frequency. That’s not usually the case with hamstring strains.

In soccer players, your typical hamstring strain occurs with sudden high load when you’re not ready for it.

Examples include:

• Jumping on a treadmill and immediately trying to hit top speeds without building up
• Subbing into a game during second half without proper warmup
• Icing your hamstring before activity
• Sprint training after an extended vacation from the sport, but at previous training volumes and loads
• Limping out of practice with a strain, then playing a game two days later

What Happens to the Muscle During a Strain?

Believe it or not, your muscles need to be torn!

When you workout with enough intensity, your muscles will develop microscopic tears.

Tiny muscle tears from exercise is a good thing. Your muscle will undergo adaptation, which is when cells repair the muscle to be stronger than before. Your muscle could even grow through adaptation, which is called hypertrophy. Adaptation and hypertrophy help you lift heavier, run faster, and look buff.

But, as you know, muscle tears can be bad.

A strain is a bigger tear in the muscle. It could be small, only affecting a few fibers. It could also be huge, completely tearing through the muscle.

When a strain happens, the muscle has to repair itself just as it does for the microscopic tears.

But, this time, there’s more to repair and it’s not seamless. Muscle fibers will be disorganized, weak, and inflexible.

Even after the muscle rebuilds, those disorganized fibers need to reorganize themselves. Rehabbing a strain to pre-injury status can take weeks to months.

Once a hamstring is strained, it has a high potential of re-strain at a shorter length. (4) It’s not as flexible, so maximum stretch and load happens earlier.

What does that feel like?

Imagine you’re recovering from a hamstring strain 2 weeks ago. You’re a midfielder subbed into the game. Your first play involves sprinting back to defense. It feels completely different. You try to get to full speed. It’s lopsided; one leg is reaching further than the other. Your hamstring is restricting your stride and you can feel discomfort after the first 2 minutes.

WHAT WOULD YOU DO: In this situation, will you (the player) request a sub after playing 2 minutes, or roll the dice and keep playing?

We see too many players placed into this situation and choose the latter. It could be for any reason: pride, obligation, competition, or embarrassment.

Recovery doesn’t always look pain-free, but discomfort after the first sprint is a clear sign that the muscle isn’t ready.

How Do I Prevent Hamstring Strains?

Here’s what you know so far about hamstring strains.

1. They usually occur with sprinting, specifically during your stride
2. They’re associated with sudden high loads when the muscle isn’t ready
3. Inflexibility of the hamstring at knee and hip contributes to injury
4. Weakness of the hamstring at its full length contributes to injury
5. If you’ve had a strain, it’s easier to re-strain it because the muscle has rebuilt differently

Now that you know what causes injury, you also know how to prevent it.

1. Sprint train at gradually higher loads – ease into top speeds and progress over time
2. Warm up properly and prepare your body for sprinting, practice, and games
3. Lengthen the hamstring across the knee and hip
4. Strengthen the hamstring at long muscle positions
5. Take time to retrain the muscle before jumping back into competition

Best Exercises to Prevent Hamstring Strains

Hint: they’re not stretching!

You could stretch, and it could help. Even so, the biggest problem remains: lack of strength at the longest hamstring position. No matter how flexible the hamstring is, if you don’t have the strength, you’re still prone to injury.

The best way to prevent a hamstring strain is to train it eccentrically, apply eccentric strength and control to the length of the hamstring, then practice sprinting.

1. Nordic Hamstring Curls: Eccentric Training

Eccentric training improves the muscle’s strength as it elongates.

Remember: When you sprint, the hamstring contracts eccentrically to slow down the progression of the leg. Since this is when hamstring strains occur most, that’s what we want to train.

Trainers rave about Nordic hamstring curls because it has the best results in strengthening the muscle eccentrically. In just 4 weeks (2x/week), it can counteract multiple risk factors for hamstring injury. (5)

The problem is that no one implements it into their training. In 2015, most teams in the Champion’s League weren’t even implementing it. (1)

But you can. Here it is.

Start in kneeling position with padding under the knees. Have a partner hold down your legs while you slowly lower to the floor, using your hamstrings to control the descent. If this is too difficult, you can add a band around your body for assistance or shorten the distance by adding a higher surface in front of you (pillows, a sofa, etc).

Suggested dosing: 2x/week. Week 1: 3 sets of 6, Week 2: 3 sets of 7, Week 3: 3 sets of 8, Week 4: 3 sets of 10; 1 minute rest between sets. (5)

2. SINGLE-LEG ROMANIAN DEADLIFTS: ECCENTRIC STRENGTH AND CONRTOL

The Nordic hamstring curl has a problem. It only challenges the hamstring at the knee, not the hip. We need to address full hamstring length at the knee and hip in a similar position to a sprint.

The solution is single-leg Romanian deadlifts.

This exercise challenges the full length of the hamstring. It’s best performed slowly to make sure you’re hitting the right muscles. You can add weight and/or change tempo to make it more difficult. High repetitions are best to mimic sprinting demands.

Start in standing. Kickstand your back leg and stiffen the muscles as you hinge forward. Reach as low as you can while maintaining a straight line with your body. You will feel your hamstring stretch on the standing leg, then contract when you stand back up. Try not to twist out of the position.

Suggested dosing: 2x/week. 3 sets of 12-15 each leg. 1 minute rest between sets.

3. Sprint Training

Ah, the rule of specificity. Sprinting will always make you a stronger sprinter.

I’m not talking about getting faster quick. That’s how a strain happens. I’m talking about gradual progressions into higher speeds.

Remember: Absolute training volume isn’t necessarily a factor in hamstring injury. Instead, sudden increase in intensity/load is.

It’s safe to do more sprint training so long as you progress gradually over time.

Start at lower speeds and less frequency, then slowly progress both to meet time or speed goals over a period of weeks to months.

Best results don’t come from specific templates or one-size-fits-all programs, especially when recovering from a strain. Sprint training is best when it’s personalized. (2) If you don’t know where to start, consult a physical therapist or trainer.

Go Forth and Prevent Injury!

Good luck! If you have a friend who needs to the best exercises to prevent hamstring strains, send them the link. Share the knowledge.

Referenced Citations

1. Bahr R, Thorborg K, Ekstrand J. Evidence-based hamstring injury prevention is not adopted by the majority of Champions League or Norwegian Premier League football teams: The Nordic Hamstring survey. Br J Sports Med 49: 1466–1471, 2015.
2. Haugen, T., Seiler, S., Sandbakk, Ø. et al. The Training and Development of Elite Sprint Performance: an Integration of Scientific and Best Practice Literature. Sports Med – Open 5, 44 (2019). https://doi.org/10.1186/s40798-019-0221-0
3. Oleksy, Ł., & Mika, A., et al. (2021). Why is hamstring strain injury so common in sport despite numerous prevention methods? are there any missing pieces to this puzzle? Frontiers in Physiology, 12. https://doi.org/10.3389/fphys.2021.586624
4. Proske U, Morgan DL, Brockett CL, Percival P. Identifying athletes at risk of hamstring strains and how to protect them. Clin Exp Pharmacol Physiol. 2004 Aug;31(8):546-50. doi: 10.1111/j.1440-1681.2004.04028.x. PMID: 15298549.
5. Ribeiro-Alvares, João Breno¹; Marques, Vanessa B.¹; Vaz, Marco A.²; Baroni, Bruno M.¹ Four Weeks of Nordic Hamstring Exercise Reduce Muscle Injury Risk Factors in Young Adults, Journal of Strength and Conditioning Research: May 2018 – Volume 32 – Issue 5 – p 1254-1262 doi: 10.1519/JSC.0000000000001975