Category: Speed

Phases Of Sprinting

12/6/2016

As we breakdown the phases of sprinting, we'll do so in 2 ways.

1) Acceleration Speed vs Top End Speed
2) Phases of the Sprinting Cycle

Each of these will present similarities, differences, and carryover that will clear up some ideas and discussion about training for enhancing speed.

Acceleration vs Top-End Speed

When talking about sport performance, especially pertaining to team sports, acceleration speed is king. Most team sports live in the 0-15-yard range, and for this reason, focusing the bulk of speed training on acceleration speed is a smart idea.

That being said, this doesn't mean top-end speed is unnecessary. In sports like football, soccer, rubgy, lacrosse, many of the big, game-breaking plays are a result of an athletes great top-end speed. So while it may occur less often than acceleration, when top-end speed is needed it's often for a big play.

Also, when we talk about top-end speed, we must realize these are not track and field athletes. What I mean by that is track and field take roughly 50-60m to reach top-end speed, and they do this on purpose.

Team sport athletes accelerate to top speed quicker out of neccesity and have been shown to reach top-end speed as quickly as 20-yards. Now with this information, when you look at many team sports, there will be many more instances when athletes will have to run 20-yards in a straight line. So while it occurs less frequently than acceleration, it does occur quite a bit and athletes adapt strategies to reach top-end speed more quickly.

All in all, the interplay of mechanics, timing, rhythm, high velocity muscular contractions and simultaneous muscular relaxation, elasticity, coordination, eccentric-isometric-concentric actions, etc make sprinting incredibly unique.

I often say if there was only one exercise to do for the rest of time - it would be sprinting.

When breaking down acceleration and top-end speed, there are different technical, mechanical, and coaching that make each unique. Knowing this will allow a coach to better communicate, cue, and evaluate each phase.

Acceleration - Characteristics

Ninety percent of sprints in soccer and 68% of sprints in rugby are 20m of shorter. Also in many sports, acceleration speed is preceded by movement. For example, a player is walking, jogging, shuffling - and all of a sudden they must shift gears and accelerate.

What does this mean?

Strictly performing acceleration drills from a standing start isn't accurate to what many sports actually experience. It's a different skill set to accelerate from a stand still, than it is from a moving start - so performing both is a must.

Let's look at some basic acceleration characteristics...

Ground Contact Times = ~.17-.22sec
Forward Body Lean = ~40-50-Degrees (depending on strength, level of athlete)
Low Heel Recovery
Foot Lands Behind COM (For first 1-3 steps for better sprinters. Foot may NOT land behind COM in low level sprinters)
Big Split in Hands

Acceleration - What To Look For

The biggest thing to look for during acceleration is if the athlete is getting a full push. We want a committed push, not a rushed, shortened turnover.
We tell our athletes all the time - don't be the cartoon character, the roadrunner - spinning your wheels but not going anywhere.

Each stride should be purposeful with the intent to put as much force into the ground as possible. As a coach you should look for...

Straight Line Heel to Head
Thigh Split - ~100-Degrees
Positive Shin Angles

The other unique aspect of acceleration is - no matter your sport, improving acceleration mechanics will help your performance. Take a look at these pictures... Every sport accelerates and knowing what to look for and HOW to improve these mechanics will improve performance.

Acceleration - What To Say

As the coaching world continues to grow and expand, it's becoming more and more evident that what we say, and how we say it matters! It's not just X's and O's, it's about communication and stimulating motor learning, and a lot of this is done by the words we use.

It's clear that external cueing is king and it's much more effective than internal cueing in improving performance and motor functioning. Porter el at (2015) showed that external cueing led to a decrease of .12sec in a 20m sprint.

Remember what we say and how we say it directly influences movement behavior. Here are some ideas on external cueing during acceleration.

PUSH, PUSH, PUSH
Push the Ground Behind You
Drive Out Like A Jet Plane Driving Down The Runway
Explode Off The Ground Like A Rocket
Pop Knee's Forward and Pop Off The Ground
Project Away From The Line Like Being Shot Out Of A Cannon

Top-End Characteristics

Top-end differs from acceleration in a few key ways, mainly body positioning and ground contact times. In fact, ground contact times are half of what is seen during acceleration phases.
This means less time on the ground to produce force and more need for elastic components and impulses. To maximize these things posture and mechanics are key, and as a coach here are some important characteristics of top-end speed...

Ground Contact Times = ~.07-.10sec
Upright Body Position
High Heel Recovery
Ground Reaction Forces = 5xBW

Top-End - What To Look For

The actions of top-end sprinting occur so quickly it is advisable to record and break it down frame by frame. Things happen just to fast for the un-trained eye, that video will give you a much better understanding of what's really happening.

When looking at sprinting, these things are a must...

Stacked Head, Spine, Hips
Neutral or Dorsiflexed Ankle
At Ground Contact
- Vertical Shin
- 100% of Height
- Swing Knee Even or In Front of Grounded Knee

Top-End - What To Say

As we touched upon earlier, the ground contact times during sprinting are under a tenth of a second. This is not enough time to actually consciously think about something or elicit change while on the ground.

This means our coaching needs to move away from words and cues that try create images of force production, and instead focus on being like a spring or pogo. Words like the following create the correct image and motor response needed for the demands of top-end sprinting.

Relax
Bounce
Push Yourself Tall
Be Light
Be Like A Whip
Snap Off The Ground

Phases of the Sprinting Cycle

To better understand what is happening during sprinting, it is important to understand the different phases of the sprint cycle. Now many people may classify the phases differently or assign them different names, but the important part is to understand, that during these times, certain actions needs to be occurring. If they are not, speed and efficiency will be limited.

1) Ground Preparation

Each phase is vitally important, but ground prep might be the most important as it dictates success during the other phases.

During ground prep, the leg is actively driving into the ground. THIS IS A MUST. An athlete cannot produce force once their foot is on the ground, there is simply not enough time. They must actively be extending and driving while the foot is still in the air.

The ankle/foot should ideally have some dorsiflexion and it cannot be plantarflexed. Dorsiflexion allows for greater stored elastic energy and shorter ground contact times.

2) Ground Contact

Ground contact occurs as the foot touches the ground. During this time, we see huge amounts of isometric strength in the whole leg as the goal is to become stiff and resist deformation.

Remember, at ground contact, the body experiences forces as much at 5xBW. The goal is to not collapse under these forces and instead act like a spring.
During initial acceleration, we want to see ground contact take place behind the COM and have a positive shin angle. During top-end sprinting, we want to see ground contact as close to under the COM as possible and have an upright shin.

At ground contact, the athlete should be 100% of their height, and their hips shouldn't overly sink or sag towards to grounded leg. As the athletes leaves the ground, they should maintain this height and actually look as though they are floating across the ground. Low, sinking runners are a sign of poor elastic abilities and lack the ability to create rigidness, and instead try to muscle through running which leads to loud steps and longer ground contact times.

3) Toe-Off

I actually classify the 2nd half of ground contact as toe-off. This is a different phase because during the 2nd half of the whole ground contact phase, the athlete needs to be actively preparing for flight.
The athlete should NOT be trying to push or continue to drive the foot behind the body. Instead they should already be dorsiflexing their ankle/foot to elicit the crossed extensor reflex and getting their leg preparing for the flight phase.

"Sprinters do not actually reach full extension because they are already actively
recovering the leg before the foot is actually off the ground"
- Ralph Mann

4) Flight
Flight phase occurs as the leg leaves the ground and gets back into position for ground preparation. During this phase we want as little backside mechanics as possible. The goal is to have the knee take the shortest path as possible to get back to the front side of the body.

As the opposite leg drives into the ground and reaches ground contact, we want to see the flight leg knee be even or in front of the grounded leg. I call this the figure 4 position.

If this position does not occur, we know the athlete is spending too much time on backside mechanics and losing valuable time.

Conclusion

Provided is some basic background on the phases of sprinting and some of the key characteristics of each. This information is important so understand HOW to address potential errors and develop a game plan to address training.

0 Comments

High Speed Hammies

10/26/2016

0 Comments

The hamstring complex is a hot topic in sports performance today, as it seems hamstring issues are plaguing the health of sport teams left and right.
A hamstring injury can now assure an athlete is out for at least 3-5 weeks and compound that with knowing a past hamstring injury is the biggest contributor to a future hamstring injury. Given the severity and re-occurrence of these injuries, everybody is after the magic pill to prevent an incident from occurring. Unfortunately, like the risk of throwing a baseball 95mph, the nature of high velocity sprinting is very demanding on the hamstrings and it's a fine line between lightening speed and a hamstring injury….

Come and see the rest of this article I recently wrote for Joel Smith of Just Fly Sports. Joel is a master when it comes to speed and jumping and this article has been very well received by his readers.

Go check it out NOW!

http://www.just-fly-sports.com/high-speed-hamstrings/

0 Comments

The Myth of Triple Extension?

9/28/2016

0 Comments

There is a fascination in the Strength and Conditioning world with triple extension. For those not familiar - triple extension is extension of 3 joints - ankle, knee, and hip.

In fact, achieving triple extension has become, in many cases, the main priority in exercise selection.

Why has triple extension become a prized possession when training athletes?

Well it has been proposed as a key in athlete performance, mainly imho, because when you look at still pictures of jumping or accelerating or sprinting coaches perceive the key performance indicator behind these movements is triple extension.

Go into Google and type in Triple Extension and here are some of the top images...

As you can see, Olympic lifting is very closely associated with triple extension and hence why it is thought to be a valuable training tool.

BUT, BUT what if I told you triple extension is far overrated? What if triple extension occurs FAR FAR LESS than what you've been told? What if I told you triple extension has only a small amount to do with athletic success?

For many it would be blasphmaomy, but let's take a deeper look at triple extension.

First, let's take a look at these picture and tell me if triple extension is occurring…

See Triple Extension?

How About During Acceleration?

When it comes to sprinting, triple extension does NOT occur. During top-end sprinting neither full hip, knee, or ankle extension occurs.

In fact, the more extension one gets, the slower they will run. In order to maximize speed, less active ankle, knee, and hip extension occurs, and the sooner flexion in these joints occur during and immediately after Ground Contact, the better.

Understand this, during top-end speed, the athlete is only on the ground for .07-.13seconds, this is no where near enough time for someone to fully extend each joint, and the more they try to, the slower they would run. The best sprinters have less hip and knee extension at toe-off

If an athlete tried to triple extend, they would create excessive backside mechanics which leads to long, inefficient GCT, and further lead to poor flight positioning of the swing leg which would finally result of the swing leg contacting the ground out in front of the body, rather than closer to the COM.

It's a deadly cycle.

During acceleration, athletes MAY triple extend during their first 1-2 steps, but after that - triple extension DOES NOT occur. Same as top-end speed, their simply isn't enough time on the ground, and extension power should be put forth during ground preparation and during the 1st half of GCT - the goal during ground contact is to get off the ground as quickly as possible.

Let's take a look at some great charts by James Wild (@wildy_jj)

The below chart shows that full hip extension doesn't occur during the 1st 3-steps, and this is amplified in team sport athletes - who are less technically proficient as sprinters.

This chart shows knee extension during the 1st 3-steps, again full knee extension is no where to be found.

This chart shows ankle extension, again the less ankle extension, the better the performance.

When it comes to the vertical jump, Chang et al. (2015) demonstrated that vertical jump performance was not dictated by triple extension. Instead, successful performance in the vertical jump could be described by knee and ankle extension, not hip extension.

In fact, I think triple flexion is on the same level of triple extension. Flexion angles of the hip, knee, and ankle are vitally important for sprinting speed. Ankle dorsiflexion is a must during sprinting, COD, and braking actions. Hip flexion is a must to allow the body to produce maximal forces during sprinting, acceleration, and jumping. Triple flexion allows the body to create a ton of stored elastic energy to be reproduced during extension phases. Triple flexion is the loading, coiling, and absorbing - extension is uncoiling and expression.

This chart shows the LESS ankle dorsiflexion range equals faster speeds… in normal english, this means the less the ankle deforms at GCT the better - so coming into GCT with MORE FLEXION can help allow less deformation, better utilization of stored elastic energy, and shorter GCTs.

At the end of the day, triple extension plays a role in athletic performance, but let's be clear - it's a lot less important than most claim.

Being able to produce extension forces IS very important, but they are not necessarily end range of motion extension forces.

So the moral of the story is this - if you're choosing your exercises/programming based on achieving triple extension, take another look because that is a poor reason to include or exclude certain exercises.

Got Get 'Em!

References

Chang, E., Norcross, M. F., Johnson, S. T., Kitagawa, T., & Hoffman, M. (2015). Relationships between explosive and maximal triple extensor muscle performance and vertical jump height. The Journal of Strength & Conditioning Research, 29(2), 545-551.

0 Comments

Muscle Activities During Sprinting

3/6/2016

1 Comment

So What Happens?

As running speeds increase so do the activation of specific muscle groups causing different joint actions. These increases are necessary for faster running speeds and knowing when and how these groups interact is important to help train speed. What is especially important in regards to sprinting and acceleration, is the available time to produce force in most cases is less than .20-sec! This means muscle contraction velocity, not necessarily maximal muscular force is key in faster running speeds.

This isn't to say muscular force isn't important, but chasing peak muscular force, when an athlete cannot produce maximal muscular contractions in the necessary time frames is a circular endeavor.

As an athlete increase his or her speed, muscles are shortened at increasingly higher velocities and have less and less time to generate the maximal forces. What this means is that many factors, such as elastic response, pre-tensing, and joint stiffness are extremely important.

With all that being said, specific musculature plays important roles during sprinting, whether it be concentrically, isometrically, or eccentrically in nature.

Let's take a look at these muscle groups and the when, how, and what they do during the sprinting cycle.

Posterior Chain

The first hip extensor we'll look at are the glutes. The glutes, specifically the glute max and glute medius, are maximized during ground contact to contribute to vertical support and stabilize the pelvis/hip to help prevent swinging, dropping, and over-rotation.

While the glute max does contribute and influence hip extension during ground preparation, it's major role is during ground contact to stabilize, resist deformation, and continue to transmit the energy built during ground prep. In this position, the glutes are in a shortened position, and act in a very isometric manner.

It is apparent that at the start of the ground contact phase, at the point that the lead foot touches the ground, the hamstrings are functioning at relatively long muscle lengths. In contrast, at the same point in time, the gluteus maximus is functioning at a much shorter muscle length. Resistance training exercises often develop strength at specific joint angle ranges of motion depending upon their point of peak contraction. Therefore, these findings may be relevant for identifying the optimal resistance training exercises for training the hamstrings and gluteus maximus for optimal performance during sprint running. The hamstrings may benefit from being trained with exercises that involve a peak contraction at long muscle lengths, while the gluteus maximus may benefit from being trained with exercises that involve a peak contraction at short muscle lengths.

Ralph Mann, the famous sprint researcher, reported the best sprinters have the greatest hip extensor moments. Bezodis et al. (2008) and Bezodis et al. (2009) both remarked upon the large hip extension moments that occurred during sprint running, providing strong support for their importance.

As the leg drives down towards the ground (what we call ground preparation), the hip extensors are the driver behind these forces and accelerating the leg, powerfully into the ground.

The next hip extensor we'll look at is the hamstring group. The hamstrings are made-up of 3 muscles - bicep femoris, semitendinosus, and semimembranosus. The group as a whole, is very active during the sprinting cycle and put under a ton of stress.

The hamstring group have the longest duration as they start activity at the beginning of ground preparation (at maximal hip flexion), and eccentrically contract - distally; while concentrically contract - locally, as they prepare for ground contact. A recent review studied the mechanics of the hamstring during sprinting, here's what they found (6).

The long head of the bicep femoris had the largest peak musculotendon strain (12.0% increase)
The semitendinosus had the greatest musculotendon lengthening velocity.
Semimembranosus produced the highest musculo-tendon force, absorbed and generated the most muscul-tendon power, and performed the largest amount of concentric and eccentric work.

As you can see, all the hamstring muscle undergo large changes in muscle length, but especially the bicep femoris with the greatest peak musculotendon strain which corresponds with the bicep femoris being the most injured hamstring muscle. Overall, all the hamstrings are stretched to great degrees during ground preparation and at ground contact and the eccentric hamstring action during ground preparation is both reason for successful sprinting, but also increased risk of injury.

The hamstrings are the primary propulsive muscles during sprinting and as you can see above, they store elastic energy during the lengthening actions they go through which is then released at ground contact.

Unlike the glutes, hamstring force is lower during ground contact and higher during group prep. This leads to a statement I use, and it leads to training methods for these muscles.

"Glutes on the ground, hamstrings in the air"

The glutes work in a shorted position, isometrically at ground contact. The hamstrings work eccentrically at the knee and concentrically at the hip, use a lot of stored elastic energy during ground preparation. Studies have shown that mirroring your training to be specific to these actions of the hip extensors (eccentrically and elastically) to be successful in preventing and rehabbing from injury (9,10).

Anterior Chain

The anterior chain doesn't get as much love as the posterior chain, but they do play an important role during the sprinting cycle and are valuable in enhancing sprinting speed.

The first group we'll look at is the hip flexors, mainly the illiopsoas. Two proposed ways increasing hip flexion strength increases sprinting speed is first it leads to a faster repositioning of the leg to get back to frontside mechanics. Second, the hip flexors are active during take-off and early flight to stop the leg from continuing to travel backwards and start the forward motion of the knee, this occurs in a stretched position and relies a lot on stored elastic energy.

Either way, hip flexion strength and cross sectional area has been positively correlated with faster sprinting speed (1,2,6,12)

Why are the hip flexors important? Faster sprinters exhibit greater hip flexion and front side mechanics angle compared to slower sprinters (7). At toe-off, the hip flexors are put under great stretch and the elastic components resist further hip extension and act like a rubber band to "snap" the hip back forward.

This means, the hip flexor complex needs to be trained at length and be able to utilize stored elastic energy to stop hip extension and "snap" the leg back to reach front-side mechanics.

Another important aspect of the hip flexor group, is flexibility. Riley et al. (2010) suggested that hip flexor mobility may play a role in the utilization of hip extension range of motion during running. If contralateral hip flexor is adequate, proper and full hip extension can take place without running into restriction or co-contraction of the hip flexor group.

The second part of the anterior chain is the quadrupeds group. During the beginning of ground contact, the quadriceps eccentrically contract to stabilize the knee joint. The primary role of the quadruped group is to provide high degrees of joint stiffness to support and absorb the vertical fall of the athlete.

Lower Leg

Ankle stiffness is key to transfer force produced up the chain into the ground and for muscles up the chain to work optimally. For example, having instability in the ankle joint decreased the activity of the glute max by over 25% (3). Instability goes in both directions - can't transfer force and leads to bigger engines not producing maximal force.

We tell our athletes this analogy all the time.

Having weak feet/lower leg is like having flat tires. Even if you are driving a ferrari,
if you have flat tires the car won't go fast.

It's the same thing with the feet/lower leg. If they are weak, maximal force won't be transferred into the ground.

The lower leg needs incredible amounts of isometric strength to resist the 4-6xBW forces being put onto them. Longer duration, low-magnitude plyometrics are a great way to build lower log/foot strength, and as athletes progress high-magnitude plyometrics are great to simulate the GRF of sprinting.

Arms

Arms are an interesting topic in sprinting and do not play as big as a role as many state. Let's be clear, the arms are neither the key to sprinting fast nor absolutely unnecessary to sprinting fast. They do play a role and assist in sprinting speed, specifically assist in horizontal propulsion during acceleration and vertical force during top-end sprinting, and they also help to counterbalance the rotary actions of the legs. If one were not to use their arms, they wouldn't be able to control the rotation the leg put onto the trunk. So, in a sense the arms help to maintain and streamline the efficiency of the sprinting cycle.

There are a couple of misconceptions about the arms... THEY DO NOT LEAD THE LEGS and THEY DO NOT STAY LOCKED AT 90-DEGREES.

We want to see the arms act in opposition of the legs while also matching timing and magnitude of the legs. Finally, it is fully expected to see extension and flexion at the elbow joint during forward and backward swing, and these should also match each other (elbow flexion on forward swing should be matched by elbow extension on backward swing).

Practical Applications

Knowing what and when things happen during the sprint cycle means a lot in terms of dictating a training plan. When we think of muscles, we think about strength, and when we think of strength, especially lower body - we think squat, deadlift, and maybe the Olympic lifts.

While these things do inherently play a role, I highly doubt increasing squat or deadlift or Olympic lift strength will lead to greater horizontal or vertical forces during the sprinting cycle. I think it would be very interesting to compare GRF during acceleration and top-end speed with strength in your typical lifts - squat, deadlift, Oly's. I'm really skeptical that strength in these lifts relates to higher GRF's, vertical or horizontal, during acceleration and/or top-end speed.

For higher level of mastery athletes, using these tools are limited at best and specific tools need to be used to enhance the qualities discussed in this article. In fact, multiple research reviews have shown that traditional strength training is moderate at best for improving sprinting speed, and this relationship goes down as the level of the athlete increases (13,14). And for those who think the almighty squat is the key to speed, know that wussy movements like the bulgarian split squat and unilateral jumps appear to more effective at enhancing speed (15,16,17).

Specificity is a must for high transfer to sprinting speed, especially for higher level athletes. For example, the hamstrings are active during ground preparation, when the hip is flexed and the knee extends eccentrically. This is in opposition of what many hamstring specific exercises or rehab program utilized.

Understand that strengthening the hamstrings are best trained at long lengths and eccentrically where the hip is kept in flexion. Also, using SSC concepts on the hamstring prepares the body for specific transfer to performance (10,11). Lastly, remember,

"Glutes on the ground, Hamstrings in the air"

Training the hamstrings in a unilateral, open chain manner is specific to the manner of execution an athlete needs. Here are some ideas for training the posterior chain for greater transference to sprinting speed.

Here are some for the anterior chain

References:

1. Deane, R. S., Chow, J. W., Tillman, M. D., & Fournier, K. A. (2005). Effects of hip flexor training on sprint, shuttle run, and vertical jump performance. The Journal of Strength & Conditioning Research, 19(3), 615-621.

2. Dorn, T. W., Schache, A. G., & Pandy, M. G. (2012). Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance. The Journal of experimental biology, 215(11), 1944-1956.

3. Webster, K. A., & Gribble, P. A. (2013). A comparison of electromyography of gluteus medius and maximus in subjects with and without chronic ankle instability during two functional exercises. Physical Therapy in Sport, 14(1), 17-22.

4. Bezodis, I. N., Kerwin, D. G., & Salo, A. I. (2008). Lower-limb mechanics during the support phase of maximum-velocity sprint running. Medicine and Science in Sports and Exercise, 40(4), 707.

5. Bezodis, I. N., Salo, A. I., & Kerwin, D. G. (2009). Athlete-specific analyses of leg joint kinetics during maximum velocity sprint running.

6. Schache, A. G., Dorn, T. W., Blanch, P. D., Brown, N. A., & Pandy, M. G. (2012). Mechanics of the human hamstring muscles during sprinting. Med Sci Sports Exerc, 44(4), 647-58.

7. Mann, R. (2011). The mechanics of sprinting and hurdling. CreateSpace.

8. Riley, P. O., Franz, J., Dicharry, J., & Kerrigan, D. C. (2010). Changes in hip joint muscle–tendon lengths with mode of locomotion. Gait & posture, 31(2), 279-283.

9. Brughelli, M., & Cronin, J. (2007). Altering the length-tension relationship with eccentric exercise. Sports Medicine, 37(9), 807-826.

10. Aquino, C. F., Fonseca, S. T., Gonçalves, G. G., Silva, P. L., Ocarino, J. M., & Mancini, M. C. (2010). Stretching versus strength training in lengthened position in subjects with tight hamstring muscles: a randomized controlled trial. Manual therapy, 15(1), 26-31.

11. Guex, K., & Millet, G. P. (2013). Conceptual framework for strengthening exercises to prevent hamstring strains. Sports Medicine, 43(12), 1207-1215.

12. Copaver, K., Hertogh, C., & Hue, O. (2012). The effects of psoas major and lumbar lordosis on hip flexion and sprint performance. Research quarterly for exercise and sport, 83(2), 160-167.

13. Rumpf, M. C., Lockie, R. G., Cronin, J. B., Jalilvand, F., & Street, D. (2015). The effect of different sprint training methods on sprint performance over various distances: a brief review. Journal of strength and conditioning research/National Strength & Conditioning Association.

14. Cronin, J., Ogden, T., Lawton, T., & Brughelli, M. (2007). Does Increasing Maximal Strength Improve Sprint Running Performance?. Strength & Conditioning Journal, 29(3), 86-95.

15. Speirs, D. E., Bennett, M., Finn, C. V., & Turner, A. P. (2015). Unilateral vs Bilateral Squat training for Strength, Sprints and Agility in Academy Rugby Players. Journal of strength and conditioning research/National Strength & Conditioning Association.

16. Holm, D. J., Stålbom, M., Keogh, J. W., & Cronin, J. (2008). Relationship between the kinetics and kinematics of a unilateral horizontal drop jump to sprint performance. The Journal of Strength & Conditioning Research, 22(5), 1589-1596.

17. McCurdy, K., Walker, J., Guerrero, M., & Kutz, M. (2010). The Relationship Between Unilateral And Bilateral Jump Kinematics And Sprint Performance.The Journal of Strength & Conditioning Research, 24, 1.

1 Comment

Can You Get Faster?

2/29/2016

0 Comments

Now to a question I get all the time.

Can I Get Faster???

The short answer is a big YES!

Anybody can most definitely get faster.

The long answer is - Everyone's genetic profile will limit the ceiling they can reach, but I have yet to find an athlete who has reached that ceiling. It's not always easy and there are a ton of factors that go into enhancing speed, but every athlete I've met has the potential to improve on their linear speed.

Here are the 3 major ways we can increase speed...

1) Mechanics

Mechanics and technique most definitely matter, and anybody who says differently is dead wrong. As research on sprint mechanics continues to poor in, it's becoming evidently clear that mechanics play a huge role in developing speed.

The orientation of force application into the ground is more important to performance than the total amount (1)

Many Strength and Conditioning professionals tend to think that it's just all about strength, and while strength matters (look number 2), it's only a small part of the equation. Athletes can't just improve their squat or clean and magically get faster, or at least reach their speed potential.

Adequate technical proficiency needs to exhibited in order to sprint fast, and this means adequate times needs to be put into coaching and teaching it.

But whenever we get into full go sprints, all of the the mechanic work goes out the window!

I hear this a lot, and I feel it's a cop out.

Coaches work their butts of to perfect squat mechanics or Olympic lift mechanics, but when you throw a max load on an athlete, often times this technique goes to hell.

So why is lifting work viewed differently than speed work?

The truth is, yes some of this mechanical work might be lost when shit hits the fan, but that doesn't mean you don't do it.

Trust me, things will stick, and if you stay after it and emphasize sprinting mechanics as much as you emphasize lifting mechanics, your athletes will get better.

Improving acceleration and sprint mechanics can be as small as altering foot strike by a few inches, body posture by a few degrees, leg path by a few inches, etc.

It's often times small changes that make huge differences, but they don't come easy, just as learning the power clean doesn't come easy.

It's takes time and understanding motor learning, and being able to convey context and intent to the athlete.

2) Strength

Strength is a touchy matter, but the truth remains - strength matters! I just don't think it matters as much as most S&C coaches think.

Depending on the level of experience, age of the participants, and the length of the study, there have been mixed results. For example, it has been shown that it takes exceptionally large increases in 1RM back squat strength (~23-27%) to only slightly increase sprinting speed (2-3%) (5,6).

A longitudinal study followed NCAA I football players at Oklahoma State University over the course of 4-years, and the researchers concluded that while athletes gained much strength in the back squat, they did not improve their sprinting speed, showing a possible disconnect between the back squat and improving sprinting speed (6)

Also consider this...

Ground contact times for acceleration are typically ~.20sec
Ground contact times for max velocity are typically ~.08-.10sec
Max force production takes ~.70sec (7)

So during speed actions, athletes are only on the ground for ~1/3 - 1/7 of the time that it actually takes to express max force production. This demonstrates the disconnect between max strength and speed, and instead demonstrates the ability and rate to apply large forces in shorter and shorter times.

Having more strength will give you a higher ceiling, but ultimately it comes down to being able to express high forces, very quickly - so yes strength does matter, but ultimately it's only a small piece of the puzzle.

In support, a recent meta-analysis by Setiz (2014) looked at 15 studies, consisting of 510 subjects showed strength in the back squat significantly correlated to sprinting speed. They concluded that lower-body strength transfers positively to sprint performance and should be noted as a relevant training regimen to coaches and athletes (4)

This meta-analysis shows the importance of strength, but here's the thing, many of these studies use novice or untrained athletes. In this case and it definitely applies to the development of athletes - strength definitely influences speed, but much of this impact is on younger, novice type of athletes. As athletes become more experienced and more developed, strength becomes less important.

Do you think Usain Bolt would get faster is he focused on improving his squat by 30lbs?

Heck no!

So when I hear S&C coaches say strength is the number 1 factor to increase speed, they are just plain wrong. This might work for young or inexperienced athletes, but tons of other factors come into play.

3) Elasticity + Stiffness

We are combining elasticity and stiffness because they are closely related and often we are talking about the same structures.

Elasticity is extremely important for acceleration and sprinting speed. As we touched upon earlier, ground contact times are much shorter than the amount of time it takes to express max force. Given this, elastic abilities become ultra important to transmit "free" forces from muscle and connective tissues. Stiffness is tremendously important to resist deformation and provide a stiff structure for the elastic properties of muscles and connectives tissues to be fully expressed.

Tendon stiffness and training the SSC has been shown to be related to higher vertical jump and sprinting speed (8-12).  The difficult thing is adaptations in connective tissues appear to take take 6 months to 2 years, compared to 3 weeks for muscle. But things like low-end plyo's, bouncing, eccentric, and isometric training are all effective for developing greater elasticity and stiffness.

We are looking to enhance stiffness throughout the body, but especially in the lower leg - To act like a pogo stick, with slight deformation but great elastic return. We tell our athletes all the time - having strong and stiff foot/lower leg complex is like having brand new, pumped up tires. Having weak feet/lower leg complex is like trying to drive on flat tires - You are very inefficient and lose all the force transmission from the hips.

Fast athletes appear to bounce and float off ground. They are quick and snap off the ground. It's amazing to hear a fast athletes feet as they accelerate and sprint. It's quick and quiet and snappy.

The great sprint coach Charlie Francis was known to say, he knew when his athletes were fatigued by the sound of their foot strike. When it became loud and poundy, he know it was time to quit the sessions.

Why?

His athletes were losing their elasticity and stiffness, and the session could only be detrimental from there on out.

This is elasticity and stiffness at it's core

Stay tuned for Part 3 - Phases of Sprinting.

Go Get 'Em

Resources:

1) Morin, J. B., Edouard, P., & Samozino, P. (2011). Technical ability of force application as a determinant factor of sprint performance. Med Sci Sports Exerc, 43(9), 1680-8.

2)  Bojsen-Møller, J., Magnusson, S. P., Rasmussen, L. R., Kjaer, M., & Aagaard, P. (2005). Muscle performance during maximal isometric and dynamic contractions is influenced by the stiffness of the tendinous structures. Journal of Applied Physiology, 99(3), 986-994.

3)  Liu, Y., Peng, C. H., Wei, S. H., Chi, J. C., Tsai, F. R., & Chen, J. Y. (2006). Active leg stiffness and energy stored in the muscles during maximal counter movement jump in the aged. Journal of Electromyography and Kinesiology, 16(4), 342-351.

4)  Seitz, L. B., Reyes, A., Tran, T. T., de Villarreal, E. S., & Haff, G. G. (2014). Increases in Lower-Body Strength Transfer Positively to Sprint Performance: A Systematic Review with Meta-Analysis. Sports Medicine, 44(12), 1693-1702.

5) Cronin, J., Ogden, T., Lawton, T., & Brughelli, M. (2007). Does Increasing Maximal Strength Improve Sprint Running Performance?. Strength & Conditioning Journal, 29(3), 86-95.

6) Jacobson, B. H., Conchola, E. G., Glass, R. G., & Thompson, B. J. (2013). Longitudinal morphological and performance profiles for American, NCAA Division I football players. The Journal of Strength & Conditioning Research, 27(9), 2347-2354.

7)  Baechle, T. R., & Earle, R. W. (2008). Essentials of strength training and conditioning. Human kinetics.

8) Viitasalo, J. T., Salo, A., & Lahtinen, J. (1998). Neuromuscular functioning of athletes and non-athletes in the drop jump. European journal of applied physiology and occupational physiology, 78(5), 432-440.

9) Wilson, J. M., & Flanagan, E. P. (2008). The role of elastic energy in activities with high force and power requirements: a brief review. The Journal of Strength & Conditioning Research, 22(5), 1705-1715.

10)  Chelly, S. M., & Denis, C. (2001). Leg power and hopping stiffness: relationship with sprint running performance. Medicine and Science in sports and Exercise, 33(2), 326-333.

11) HENNESSY, L., & KILTY, J. (2001). Relationship of the stretch-shortening cycle to sprint performance in trained female athletes. The Journal of Strength & Conditioning Research, 15(3), 326-331.

12) Harrison, A. J., Keane, S. P., & Coglan, J. (2004). Force-velocity relationship and stretch-shortening cycle function in sprint and endurance athletes. The Journal of Strength & Conditioning Research, 18(3), 473-479.

0 Comments

Forces For Speed

2/25/2016

1 Comment

Within the sprinting community, there is much debate about the most important forces that are necessary for faster sprinting speeds.

Is it horizontal or vertical?

Is one more important during certain phases of acceleration vs top-end speed?

Why the confusion?

Let's take a look into both Horizontal and Vertical forces and clear the air about both of them.

Horizontal

Recent research has shown high levels of horizontal force application is related to faster sprinting speeds, especially acceleration speed. Horizontal forces can be seen in two lights

Those that propel us
Those that brake us

The latter being often forgotten. Obviously positive horizontal forces will act to propel us forward, but each ground contract is met with friction and placement of the foot compared to the COM - these inherently cause horizontal braking forces.

With that being said, there has been a barrage of recent research showing the contributions of horizontal forces and impulses as being major players in sprinting speed.

In fact, it would be safe to summarize that it appears horizontal forces are of greater importance to sprinting speed than vertical forces - but there may be some caveats.

Vertical

There are a few constants in our life - taxes, death, and GRAVITY to name a few.

Gravity is the force that we cannot avoid discussing as it will always be there and will always play a huge role in sprinting speed. Like it or not, gravity acts on all of us as we sprint.

As we push and drive off the ground, we fight gravity.
As our center of mass falls back to the ground after the flight phase, we must fight gravity.
At ground contact, we must be resilient and resist crumpling, must of which has to do with gravity.

The fact that no one on earth can hide from gravity, makes it pretty clear that during the sprinting cycle, we must fight the forces of gravity and these forces are inherently vertical.

The popularity of vertical forces can be traced back to the most famous study in sprinting history - Peter Weyand's sprinting study done in year 2000 at his famous SMU sprinting laboratory. Weyand et al (2000) looked at correlations between vertical forces and sprinting speed of 33 subjects. Vertical forces were found to be significantly greater in faster runners than slower ones (7).

Since, this study has been the backbone for the vertical force side, but we must also realize the correlation coefficient between vertical force and running speed was only (r = 0.39), which is considered low by most standards. Also the researchers did NOT test for horizontal forces - so there were no comparative measures.

Still, it is undeniable that vertical forces play a role in sprinting performance.

Acceleration Speed vs Top-End Speed

It appears that both horizontal and vertical forces play a role in sprinting speed, but do different phases of sprinting - acceleration vs top-end - have different levels of horizontal vs vertical importance?

Acceleration

Let's breakdown a few studies and see what the literature says...

Buchheit et al (5) analyzed the horizontal forces of 86 elite youth soccer players during sprinting. The researchers found that horizontal force was significantly correlated with acceleration speed (10m) but not maximum sprinting speed, suggesting horizontal forces may be more important for acceleration performance than maximal sprinting performance.

Morin et al (4) looked at different phases of a 40m sprint. The researchers found that net horizontal impulse and propulsive horizontal impulse were strongly correlated to sprinting performance in the 40m sprint, but vertical impulses was not (4). Now the 40m dash is a combination of both acceleration and top-end speed, but most would argue acceleration performance is probably more important than top-end speed.

Almost 30-years ago Mero (1988) analyzed the sprints of elite Finnish sprinters over 10m from a block start. Mero found a couple of important nuggets. First, at the first foot contact, even though the foot landed behind the COM by over 10cm, there were still horizontal braking forces to overcome. So even a positive angle at foot contact BEHIND the COM still equaled horizontal braking forces, demonstration that no matter what there will be horizontal forces to be overcome.

Friction = needing to overcome horizontal forces = slowing down.

Second, Mero found correlation between horizontal forces in the first step and at 10m and sprinting speed. These same correlations, however, were not found in regards to vertical forces (3).

De Lacey et al. (2014) looked at 39 rugby players from the National Rugby League. They looked at the 10m and 40m dashes on a non-motorized treadmill and compared the differences between backs and forwards. They found faster players produced significantly greater relative horizontal force and power. The researchers concluded that developing force and power in the horizontal direction may be beneficial for improving sprint performance in professional rugby league players (6).

Top-End

Morin et al (2) analyzed 13 male subjects with different sprint performance levels ranging from novice to world class ability. The researchers found that peak sprinting velocity was related to both vertical and horizontal forces, but the correlation for horizontal was stronger (r=0.59 vs r=0.79).

We already reviewed Weyand et al. (2000) and this remains the vocal research paper for the vertical forces group.

Brughelli et al (1) looked at 16 high level Australian soccer players as they sprinted over a Woodway force treadmill at speed ranging from 40-100% max sprinting speed. The researchers found that as speed increased from 40 to 60%, peak vertical and peak horizontal forces increased by 14.3% and 34.4% respectively. But as the subjects increased speed from 60-80% speed, changes in peak vertical and peak horizontal forces were 1.0% and 21.0% respectively. Finally, as the subjects increased speed from 80-100% speed, changes in peak vertical and peak horizontal forces were 2.0% and 24.3%. Overall, the researcher concluded it would seem that increasing maximal sprint velocity may be more dependent on horizontal force production as opposed to vertical force production (1)

Kale et al. (2009) looked at 21 male sprinters and ran these subjects through a gamet of tests. They found that ability to produce vertical force, in the form of a depth jump, was the most strongly correlated test to 100m dash sprinting speed. In conclusion, vertical power and force in the form of a depth jump was an effective way to reflect maximum running velocity. The thought process of the researchers is that this same vertical force in the depth jump, is very applicable to the manner of force application during max velocity. But as we know, correlation does not equal causation (8).

Overall Thoughts

Running fast cannot be zoned into just a single force or factor, speed is multi-dimensional with many different aspects being intertwined. If anyone says it's just a single force or single factor... run, run away fast!

The other factor that seems obvious to me, is the action of the body is very similar in both stages - acceleration and top-end speed - and the difference seen in forces is just a outcome of body positioning.

As Mike Young has said - "Acceleration is just top speed turned on it's side".

The actions of the body are the similar/same, it's just body orientation in relation to the ground that differs and this is where changes in forces is seen.

Take a look a Usain Bolt accelerating in the picture below.

Now tilt that picture to the right, and you get what look like pretty solid top-end mechanics.

Now we could critique some minor differences between this tilted picture and perfect top-end mechanics, but in my opinion, the differences you see in forces are largely due to the orientation of the body and the natural outcome from these positions rather than anything largely different in terms of intent or muscle actions.

Now what's interesting is in Weyand's first study back in 2000, most S&C coaches interpreted the results from that study - more vertical force = more speed - as a need to increase an athletes squat and deadlift strength and that will increase speed.

Well, we know it doesn't really work that way. We know GCT is under .20 for acceleration and .10 for top-end speed, not even close to enough time to put maximal muscle force into the ground.

Also, I haven't seen a study done, but I would be really interested in seeing if gains in strength in the back squat or deadlift actually increase vertical and/or horizontal ground forces.

I really don't think if adding pounds onto an athletes squat or deadlift will actually carryover to greater ground forces. It would be interesting to see a correlation done on these weight room strength numbers and ground forces (both vertical and horizontal). I think in novices there may be a slight relationship, but I highly doubt at higher ability levels you'd see any relationship.

This isn't to say lifting isn't important, I feel it improves qualities in other realms that transfer to ground forces. Things like stiffness, resisting deformation, body composition, motor unit recruitment, rate coding, and muscular coordination/timing. These will all help speed in different ways, but I truly believe it's not as simple as more force in the weight room = more force applied during sprinting, otherwise the strongest people would also be the fastest.

That's all for now. Stay tuned for our next installment on muscle actions/activities.

Go Get 'Em!

References

1) Brughelli, M., Cronin, J., & Chaouachi, A. (2011). Effects of running velocity on running kinetics and kinematics. The Journal of Strength & Conditioning Research, 25(4), 933-939.

2) Morin, J. B., Bourdin, M., Edouard, P., Peyrot, N., Samozino, P., & Lacour, J. R. (2012). Mechanical determinants of 100-m sprint running performance. European journal of applied physiology, 112(11), 3921-3930.

3) Mero, A. (1988). Force-time characteristics and running velocity of male sprinters during the acceleration phase of sprinting. Research Quarterly for Exercise and Sport, 59(2), 94-98.

4) Morin, J. B., Slawinski, J., Dorel, S., Couturier, A., Samozino, P., Brughelli, M., & Rabita, G. (2015). Acceleration capability in elite sprinters and ground impulse: Push more, brake less?. Journal of biomechanics.

5) Buchheit, M., Samozino, P., Glynn, J. A., Michael, B. S., Al Haddad, H., Mendez-Villanueva, A., & Morin, J. B. (2014). Mechanical determinants of acceleration and maximal sprinting speed in highly trained young soccer players. Journal of sports sciences, 32(20), 1906-1913.

6) De Lacey, J., Brughelli, M. E., McGuigan, M. R., & Hansen, K. T. (2014). Strength, Speed and Power Characteristics of Elite Rugby League Players. The Journal of Strength & Conditioning Research, 28(8), 2372-2375.

7) Weyand, P. G., Sternlight, D. B., Bellizzi, M. J., & Wright, S. (2000). Faster top running speeds are achieved with greater ground forces not more rapid leg movements. Journal of applied physiology, 89(5), 1991-1999.

8) Kale, M., Asçi, A., Bayrak, C., & Açikada, C. (2009). Relationships among jumping performances and sprint parameters during maximum speed phase in sprinters. The Journal of Strength & Conditioning Research, 23(8), 22

1 Comment

Random Speed Thoughts

2/12/2016

0 Comments

Enjoy these random thoughts on speed!

Speed is about producing force in the right direction and applying that force in the shortest amount of time - This means neuromuscular efficiency, technical/mechanical mastery, stiffness, usage of elastic components, relaxation, rhythm, timing, coordination are all important

Research has shown that triple extension is neither optimal nor necessary in many of the steps during acceleration or top-end speed - what again is the fascination with triple extension?

The main goal in top-end sprinting is front side mechanics. A common error is what path the foot travels at toe-off. Does it keep traveling backwards & upwards or does it travels forward & upward? Upwards and forward is optimal - backwards and upward is wasted motion and time. Pause the video at 5-seconds and see the difference of foot location.

An easy way to look for efficient front side mechanics is to look where the knees are at ground contact. During optimal and efficient mechanics, the knees will line-up at foot contact. During poor mechanics and backside dominant mechanics, the flight leg knee will lag behind. Pause the above video at 6-seconds and look at the differences in knee location and it's clear to see wasted time and what will be a lack of front side mechanics by the athlete on the right, which will in turn equate to less force production.

A favorite drill of mine to improve front side mechanics and "naturally" develop better positioning at foot contact is wickets

Errors made during acceleration lead to errors in top-end speed. Quality acceleration = quality top-end

Relaxation is key for top-end speed. As Yuri Verkhoshansky stated, "Relaxation is very important for high velocity movements". Being able to quickly contract and relax is vitally important for maximum efficiency - and not being able to relax will lead to early fatigue, loss of mechanics, and tightening up - all equal a loss of speed and recovery. An easy place to look as at the face or shoulders - are they tense and stiff? If so, the athlete needs to work on relaxation. - Also read THIS

A key area I see missing in athletes in ankle stiffness. More ankle stiffness = better stored elastic energy, lower GCT, and more effective force transfer into the ground. This is achieved by better foot/ankle positioning during ground prep and ground contact - mainly dorsiflexion. Also, I'm a big fan of longer duration, low intensity hopping/jumping exercises - This teaches proper ground contact positioning and builds the base of ankle/foot stiffness needed for high speed running.

Speed drills don't directly make one faster - what they do is create context and give the athlete a better understanding and feel of body positioning, trunk and shin angles, tempo, rhythm, posture, and coordination needed to accelerate and reach top-end properly. Drills take time for transfer, but over time, the qualities gained and developed through the context of drills WILL transfer towards better, more efficient mechanics.

Getting faster will increase numbers in the weight room, but increasing numbers in the weight room will not necessarily improve sprinting speed

The foot contacts behind the COM during the first 1-4 step during acceleration = body positioning, shin angle. I keep hearing a big name coach say this doesn't happen and it drives me nuts - Read this MONSTER

Continuing on the dorsiflexion path - can't emphasize enough the importance of getting proper dorsiflexion and gaining dorsiflexion ROM. Faster sprinter's not only exhibit dorsiflexion during ground prep and contact, but they initiate the dorsiflexion signal earlier at toe-off. Ingraining dorsiflexion in as many movements as possible innately teaches the athlete the crossed extensor reflex - which leads to shorter GCT and quicker flexion after toe-off.

Arms are neither a maker or breaker of high running speeds. They do contribute to certain aspects of speed enhancement, but they DO NOT lead the legs and are not going to be the major difference in speed enhancement.

The majority of team sports should focus much of their attention on acceleration speed. They should also do so from various start positions, various stimulus to react to, various movements to proceed the acceleration, etc.

Probably the quickest way to instantly improve speed is to improve body composition/lose weight. As Charlie Francis said, "Fat don't Fly!"

Technique matters:

What we say as a coach can effect speed performance. External cues have been shown to be effective at enhancing speed performance

- Acceleration = PUSH, Drive the ground behind you, Explode like being shot out of a cannon, Drive your knee forward like your breaking a glass window
- Top-End = Stay tall, Bounce, Snap off the ground, Act like your running on hot coals, Imagine your running in knee high grass, Imagine a Lion is chasing you

The Crossed Extensor Reflex is a very interesting concept, and one that I believe plays a big role. The hard part is trying to train or develop this reflex into our athletes. My thought is repetitions and repetitions of dorsiflexion to ingrain it subconsciously.

That's all for now.

Go Get 'Em!

0 Comments

Wisconsin Track and Field Coaches Clinic

2/6/2016

0 Comments

I had the pleasure of speaking at the Wisconsin Track and Field Coaches Clinic this past weekend in Madison. I had two sessions

Considerations for Cold Weather Training
Building Speed in the Weight Room

It was a great experience and track coaches are always an awesome audience to speak to. I also had the privilege to work and talk shop with legendary speed coach, Loren Seagrave. All in all a great weekend, and look forward to going back.

If you want my presentation on Considerations for Cold Weather Training, email me at buildingbetterathletes.bba@gmail.com

Here is the Building Speed in the Weight Room

0 Comments

Speed: What Is It?

1/3/2016

0 Comments

This will be a multiple part series, going to everything and more you want to learn about speed.

Our first segment will discuss what speed technically is and a major common myth about speed.

Defining Speed:

What exactly is speed?

A common definition many learn is...

Speed = Stride Length x Stride Rate

While this technically is correct, it is a massive over sight and sends the wrong message.

That wrong message ends up with many strictly seeking to improve length and rate, rather than understanding these are actually byproducts of what happens on the ground.

Stride rate and stride length are outcomes of how one applies force into the ground.

The amount, direction, and time of this force application directly dictates ones length and turnover of their stride. Trying to find ways to artificially increase stride length or rate doesn't actually attack the issue, and instead makes things worse.

Seeing someone with what might be deemed as slow turnover or short strides, we have to ask ourselves why?

We can't just say, "take larger strides!" We need to find the root of the problem and look at what is going on at foot strike, what is going on at each joint, is there mobility restrictions, strength limitations, poor elasticity, technical errors, poor intent, etc.

Trying to change rate or length without looking at all these factors that actually effect them is a road to nowhere.

Remember Speed ≠ Stride Rate x Stride Length

Speed = Application of Huge Forces in a Specific Direction in the Shortest Amount of Time

As we delve into later posts - we'll break down how this definition gives us a better insight as to how to train for speed and a model to break down speed development.

Stay tuned!

0 Comments

Blog

Phases Of Sprinting

High Speed Hammies

The Myth of Triple Extension?

Muscle Activities During Sprinting

Can You Get Faster?

Forces For Speed

Random Speed Thoughts

Wisconsin Track and Field Coaches Clinic

Speed: What Is It?

Michael Zweifel CSCS-

Archives

Categories