How Bigger Hamstrings Will Improve Your Athleticism and Prevent Injury

Let's talk about everyone's favorite chain: the posterior chain. So many songs have been written about it, but yet, some people oddly neglect to sufficiently train the glutes and hamstrings.

With this overwhelming abuse of the quadriceps complex, it is important that lifters prioritize isolation of the hamstring muscles to balance out the discrepancy in strength. Hamstring strength can play a role in improved power output, running economy, and may even reduce the risk of injuries like ACL tears.

As much as I love squats (and believe them to be one of the most beneficial exercises), the squat does not actually activate the posterior chain as much as many people think. In fact, many people squatting are quad-dominant, and under-utilize the gluteus maximus.

Before I elaborate, we need to review a little bit of anatomy. The muscles we refer to as the "hamstrings" are actually three separate muscles: the biceps femoris (which has a long head and a short head), the semimembranosus, and the semitendinosus. These two joint muscles work together to flex the knees and extend the hips.

Now that that's out of the way, we can talk about how these muscles affect performance. Since they act as hip extensors, strong hamstrings are going to be crucial for a high jump and a fast sprint. A 2007 study on sprinters concluded that "[...]the muscles mainly responsible for forward propulsion in full speed sprinting are the hamstrings, the glutaeus maximus and the adductor longus. The hamstrings are singled out as the most important contributors to produce highest speed levels." Essentially, an athlete with well-developed hamstrings will be able to horizontally accelerate much faster than an opponent with weaker hamstrings. Each stride will allow him to generate greater hip extension, getting more power as he straightens his legs. While quadriceps strength is necessary, it is the posterior chain that allows him to push harder off of the ground.

Similarly, another study found that runners with a smaller hamstring-to-quad ratio, meaning that there was not as big of a strength/size disparity between the two muscles, had a better running economy. This balance between the quadriceps and the hamstrings allowed the runners to be more efficient in their cadence. It was deduced that "runners should consider implementing hamstring exercises to improve their f-H:Q (hamstring to quad) ratios."

Usain Bolt has some serious hamstring pump.

The muscles activated in jumping are very similar to those we recruit in sprinting. While sprinting is unilateral, jumping is a bilateral movement. The extension of the hips, knees, and ankles, however, is much the same.

A four week study on males (with no strength training experience) found that the Nordic hamstring exercise (which I will show you later in this article) "[produced] favourable neuromuscular adaptations for the possible prevention of hamstring injuries while enhancing performance in athletic, untrained males." Using this exercise, on average, their vertical jump heights increased by about 6.3 cm in a month! That's pretty substantial. Granted, these are untrained individuals, but athletes could still reap some benefits from building the hamstrings.

I am a firm believer that a stronger, all-around, individual will be more resilient to injury. There is a decent amount of evidence to support the idea that hamstring strengthening can prevent the incidence of hamstring pulls, ACL tears, and other such injuries.

Askling et. al. tested hamstring injury in high-level soccer players. He put the players on an eccentric hamstring strengthening protocol 1-2 times a week for 10 weeks. "The results showed that the occurrence of hamstring strain injuries was clearly lower in the training group (3/15) than in the control group (10/15). In addition, there were significant increases in strength and speed in the training group." So the players got stronger, faster, and stayed injury free. What more could an athlete or a coach want!?

Here's the part you've been waiting for--the exercise section:

1. Russian leg curls
2. Good-mornings
3. Hip extensions (add weight if necessary)
4. Single leg RDL
5. Barbell hip thrusters
6. Stability ball leg curls 
7. Single leg sliding leg curl (advanced)
8. Slow eccentric RDLs
9. Reverse hypers
10. Stiff legged deadlifts

Not only will you have a better-looking rear-end, you'll be stronger, faster, and more injury resistant. Sounds like a win, win, win to me. Build those posterior chains!

Works Cited:

1. Askling, C., J. Karlsson, and A. Thorstensson. "Hamstring Injury Occurrence in Elite Soccer Players after Preseason Strength Training with Eccentric Overload." Scandinavian Journal of Medicine and Science in Sports Scand J Med Sci Sports 15.1 (2005): 65. Web.
2. Blazevich, Anthony John. "Optimizing Hip Musculature For Greater Sprint Running Speed." Strength and Conditioning Journal 22.2 (2000): 22. Web.
3. Clark, Ross, Adam Bryant, John-Paul Culgan, and Ben Hartley. "The Effects of Eccentric Hamstring Strength Training on Dynamic Jumping Performance and Isokinetic Strength Parameters: A Pilot Study on the Implications for the Prevention of Hamstring Injuries." Physical Therapy in Sport 6.2 (2005): 67-73. Web.
4. Mjolsnes, Roald, Arni Arnason, Tor Osthagen, Truls Raastad, and Roald Bahr. "A 10-week Randomized Trial Comparing Eccentric vs. Concentric Hamstring Strength Training in Well-trained Soccer Players." Scandinavian Journal of Medicine and Science in Sports Scand J Med Sci Sports 14.5 (2004): 311-17. Web.
5. Moir, Gavin, Ross Sanders, Chris Button, and Mark Glaister. "The Effect of Resistance Training on Hip-Knee Continuous Relative Phase Measures during Accelerative Sprinting." Medicine & Science in Sports & Exercise 39.Supplement (2007): n. pag. Web.
6. Nuckols, Greg. "Hamstrings: The Most Overrated Muscle for the Squat 2.0 • Strengtheory." Strengtheory. N.p., 29 Apr. 2015. Web. 27 May 2015.
7. Sugiura, Yusaku, Tomoyuki Saito, Keishoku Sakuraba, Kazuhiko Sakuma, and Eiichi Suzuki. "Strength Deficits Identified With Concentric Action of the Hip Extensors and Eccentric Action of the Hamstrings Predispose to Hamstring Injury in Elite Sprinters." J Orthop Sports Phys Ther Journal of Orthopaedic & Sports Physical Therapy 38.8 
8. Sundby, Øyvind H., and Mark L.s. Gorelick. "Relationship Between Functional Hamstring." Journal of Strength and Conditioning Research 28.8 (2014): 2214-227. Web.