The First 10m the Most Important for Short Sprint Performance in Sport?

If you’ve ever played a team field sport, I’m sure you’ve heard the saying the first 10m of the sprint is the most important when making a fast action play such as chasing after a ball or someone or making a line break. But is there any research out there to back this up?

 

A new study has been recently published last month (July 2015) by Morin and colleagues. It is titled “Acceleration capability in elite sprinters and ground impulse: Push more, brake less?” This paper may help us gain a better understanding into short sprint performance and the saying “the first 10m is the most important.”

So what did the researchers have the subjects do?

7 sprints were performed per subject (2x10m, 2x15m, 20m, 30m and 40m) with 4mins rest between sprints.

How was the data collected and what was collected?

A 6.6m force platform was used in an indoor track. Vertical, horizontal and mediolateral ground reaction force were measured using this device. Within this, backward orientation of the horizontal force vector (braking impulse IMP_h-) and forward orientation of the horizontal force vector (propulsive impulse IMP_h+). You may be wondering how a 6m force platform could measure variables over a 40m sprint. Well starting blocks started over the platform for the first 10m sprint and the starting blocks were placed further and further back from the force platform for each subsequent sprint (15-40m). In doing so, the researchers were able to create a “virtual” 40m acceleration getting data from foot contacts over the full 40m distance.

What were the characteristics of the subjects?

9 elite (international level) or sub-elite (French national level) male sprinters with personal best 100m times ranging from 9.95-10.60sec. As stated by the authors, the range of performances is not that narrow hence the findings of this study may not only apply to just high level sprinters.

What are some of the relevant findings and what do they mean?

40m sprint performance was significantly correlated to high values of overall horizontal force. However, IMP_h+ was siginicantly positively correlated with 40m sprint performance while IMP_h- was not. The result of this shows IMP_h+ to be the key factor in 40m sprint performance. In layman’s terms, the faster athletes are the ones that “push” more in the horizontal directon.

Another important finding was that vertical force was not correlated to sprint acceleration performance and more importantly, there was a non-significant tendency towards a negative correlation between vertical force and 40m performance. Meaning, if you are producing more vertical force over horizontal force during your sprint (i.e. accelerating with a very upright posture orientating force more vertically while sprinting), you may negatively impact your 40m sprint performance.

Finally, 40m values were correlated with the first 0-20m and the second 20-40m part of the sprint. The correlations were similar as above when correlating the values with the first 20m. However, no correlations were found over the second section of the sprint (20-40m). This indicates that much of the 40m sprint performance is determined by how much horizontal force is produced over the first 20m, with as much IMP_h+ (push) as possible.

Summing up

So it seems that statement of “the first 10m being the most important” may be true and have some scientific backing. This study suggests that the first 0-20m of the sprint is the most important in regards to these mechanical variables for short sprint performance.  In order to have a fast first 20m, according to this research an athlete needs to be able to produce high amounts of horizontal force relative to body mass with minimal force being produced in the vertical force vector. There is potential for these findings to guide training for field sport athletes such as soccer or rugby where short sprint speed is vital to performance.

Practical Application

One simple way to train this attribute is the use of heavy sled drags. This will make you closer to parallel to the ground and will force you to “push” in the horizontal direction. I have listed some other exercises in a previous post HERE.

References

http://www.ncbi.nlm.nih.gov/pubmed/26209876

Horizontal Exercise Combo

A little exercise combo to help develop horizontal force and velocity capabilities we used at Olimpia CSM Bucuresti Rugby.

Developing Horizontal Force & Velocity Capabilities

One of the supersets we used with our rugby union backs during preseason to develop horizontal force & velocity at Olimpia CSM Bucuresti

The "Overshoot Phenomenon" (Part 3)

We have now observed the "overshoot phenomenon" occur in two separate studies Andersen et al. (2000 & 2005). However, these were both seen in sedentary subjects where long periods of detraining are not going to affect performance as it would in professional athletes. One study has looked at the "overshoot phenomenon" in a professional team sport setting but rather than observing changes in muscle fibre type, performance based variables were implemented (de Lacey et al. 2014).

So what were the characteristics of the subjects?

Seven professional rugby league players from a National Rugby League Club, including 2 international players (age: 24 ± 3.6; height: 183.0 ± 6.1cm; weight: 99.0 ± 12.2kg).


What was done leading into the tapering period?

Four months of preseason training consisting of resistance (weight) training was performed 3-4 times a week averaging approx 60mins a session. Field sessions (fitness and skill sessions) were performed 3-4 times a week averaging approx 60mins a session. 

What is a taper and when and how was the taper structured?

A taper is a reduction in training load over a period of time with the aim to reduce stress on the body and mind of daily training and optimise sport performance. Reducing the training load can be done by manipulating training intensity, volume, duration, frequency and mode. 

In this study by de Lacey et al. 2014, a step taper was implemented 21 days out from the start of the first round of the NRL season. A step taper is where training load is suddenly reduced rather than gradually. In this instance, the reduction of training load was manipulated by the reduction in training volume while intensity (how heavy you lift) remained high. 

During the taper, the subjects performed only 1 resistance training session each week while field sessions remained the same.

What was measured and how?

To keep this simple and least sciencey as possible, I will make this brief. 10 concentric only squat jumps were performed by each athlete using ascending loads, with 2 jumps being performed at each load (0, 25, 50, 75 & 100% body mass). Jump height was measured with a linear position transducer and using some additional leg measurements, a force/velocity profile was constructed for each subject. This was done both pre and post taper.

Before we go into the results, here are some definitions of variables that were used to make this easier to understand.

F0 - theoretical maximum force (i.e. the amount of force that the subject can produce and zero velocity)

V0 - theoretical maximum velocity (i.e. the velocity the subject can produce at zero load)

Pmax - maximal power (i.e. the product of F0 and V0)

Sfv - the slope of the force/velocity profile. This is determined by F0 and V0.

NOTE: I will explain the importance of the force/velocity profile in another post as it will make this already long post even longer.

What happened from pre to post taper?

	Pre Taper	Post Taper	ES ± CL	Inference
F0 (N/kg)	54.93 ± 25.71	64.74 ± 16.87	0.45 (0.05;0.85)	Small*
V0 (m/s)	2.71 ± 0.63	2.86 ± 0.58	0.24 (-0.44;0.91)	Small
Pmax (W/kg)	34.87 ± 10.97	44.71 ± 6.72	0.85 (0.46;1.24)	Moderate**
Sfv	-22.39 ± 14.09	-24.09 ± 9.69	0.23 (-0.26;0.72)	Small
Jump 25% (cm)	39.59 ± 8.52	47.74 ± 4.65	0.90 (0.20;1.60)	Moderate*
Jump 50% (cm)	31.66 ± 8.49	42.09 ± 4.63	1.04 (0.65;1.42)	Moderate***
Jump 75% (cm)	25.41 ± 9.13	36.39 ± 6.49	0.94 (0.58;1.30)	Moderate***
Jump 100% (cm)	21.20 ± 9.51	30.30 ± 5.08	0.83 (0.38;1.28)	Moderate**

Unclear, *Likely positive, **Very Likely positive, ***Most Likely positive, F0= theoretical maximum force, V0=theoretical maximum velocity

Table 1. Results from pre and post taper

From the table above, we can see a likely small increase in F0 while improvements in V0 and Sfv were unclear. Pmax and the four performance variables however showed likely to most likely moderate increases from pre to post taper.

Did an "overshoot" occur?

While muscle biopsy's were not taken in the present study, we can assume an "overshoot" did not occur as velocity capabilities changes were unclear as well as changes in Sfv. As explained in part 1, Type IIX muscle fibres have the fastest contraction time of all the muscle fibre types so more Type IIX muscle fibres would mean a greater V0 which did not occur. Also, Sfv became slightly more negative indicating the slope of the force/velocity profile moving towards force capabilities rather than velocity.

So what does this all mean and what can we do with this information?

In a short roundabout way, this data suggests that a 21 day taper is long enough to illicit a positive change in maximal power AND performance. These positive changes seem to be influenced by the increase in force capabilities rather than velocity which goes against the study by Andersen et al. (2005) explained in previous parts. One of the potential reasons for this was the taper length as the present study tapered for 21 days while Andersen et al. (2005) detrained for 3 months. For a professional athlete, this would never be possible. Therefore, a short step taper implemented in this fashion leading into a season could be used to "peak" athletes for their first competition game.

There are many things we still don't know when it comes to tapering, force/velocity profiling and "overshoot." E.g. how long do these changes last? Do these changes affect any other areas of performance i.e speed? What is the optimal taper length to illicit the greatest positive changes? Can we do this during the season to peak for playoffs? Hopefully these questions can be answered in future research.

I know detail was brief but this was going to be far too long if I added all the details. I will write a separate post with more details about force/velocity profiling and why it is such an important part of a strength and conditioning program.

References: http://www.ncbi.nlm.nih.gov/pubmed/?term=de+Lacey+2014+taper
                    http://www.ncbi.nlm.nih.gov/pubmed/15731398

The "Overshoot Phenomenon" (Part 2)

Carrying on from the previous post, both Andersen et al. (2000 & 2005) showed decreases in Type IIX and increases in Type IIA muscle fibres post training compared to baseline. Once these measures were taken, a 3 month detraining period was implemented. Detraining meaning no resistance training was performed and the subjects returned to their normal daily lives (subjects in both studies were sedentary, no previous regular resistance training and no regular exercise within the last year).

So what happens after a detraining period?

The proportion of Type IIX muscle fibres increased past baseline PRE training values while the proportion of Type IIA muscle fibres significantly decreased below PRE training values.  This is known as the “overshoot.” (Type IIX surpassing pre training values).

What about performance post detraining period?

Andersen et al. (2005) used isokinetic, maximal unloaded knee extension and evoked muscle twitch to measure performance.

Isokinetic testing if anyone didn't know what this machine was

Isokinetic muscle strength and power at 30˚ and 240˚ decreased back to pre training levels. However, angular velocity, angular acceleration, total moment of force, and power during the maximal unloaded knee extension all significantly increased past PRE and POST training values. Furthermore, peak twitch rate of force development (RFD) significantly increased post detraining compared to pre and post training.

An interesting point to note is that the subjects produced greater force post detraining at greater velocities compared to both pre and post training. Also, subjects produced more power compared to pre and post training at greater angular velocities. From these data, we could speculate that the overshoot may only relate to high velocity unloaded movements (E.g. punching, sprint cycling). However, I have also heard this method being used in bobsled with the starting push with great success so even some loaded velocity movements may benefit.

Part 3 will add a study looking at the overshoot with more of a performance based view in professional athletes to see whether or not this phenomenon can be seen in a sporting context. 

The “Overshoot Phenomenon” (Part 1)

There are only a few papers to date showing the “overshoot phenomenon” (Andersen et al. 2000 & 2005) and only one paper done using professional athletes within a season (de Lacey et al. 2014). Explained very simply, an “overshoot” occurs when a taper or detraining from resistance training takes place. Or in other words, time off is taken from resistance (weight) training. Anecdotally I have heard the Great Britain cycling team used this leading into the 2008 Beijing Olympics for the track cycling and cleaned up the gold medals. For now, let’s go into a little more detail.

There are 3 types of pure muscle fibres (to keep it very simple). Type I, Type IIA and Type IIX. Muscle fibres can also posses more than one type, e.g. Type IIA/IIX, but for now, we’ll stick to just 3 fibre types. Type I are your slow twitch fibres contributing more to the endurance aspect of muscle contraction. Type IIA and IIX are your fast twitch fibres and contract much more rapidly than Type I. Type IIX contract approximately twice as fast as Type IIA and about 5-10 times faster than Type I but fatigue very quickly.

As resistance training is undertaken for an extended period of time, (e.g. in Andersen et al. 2000 & 2005 it was 3 months for a total of 38 sessions) an adaptation occurs where the number of Type IIA muscle fibres increase while the number of Type IIX decrease compared to pre training. As shown in Andersen et al. (2000), a significant increase in Type IIA and a significant decrease in Type IIX were found post training. So we have a decrease in the bodies most powerful muscle fibres and an increase in more efficient fast twitch fibres.

So how do we increase Type IIX muscle fibres and potentially muscular power? Could this be useful for your sport you compete in? These will be explained in upcoming parts!

References:
http://www.ncbi.nlm.nih.gov/pubmed/10883005
http://www.ncbi.nlm.nih.gov/pubmed/15731398

Contrast Training to Develop Horizontal Capabilities

As promised, here are a few examples of complexes to develop horizontal capabilities.

A1. Hip Thrust 3-5x5-10             

A2. Broad Jump 3-5x1-4

A1. Heavy Sled Push or Drag 3-5x10-40m

A2. 10m Sprint 3-5x1

A1. Heavy 45˚ Back Extension 3-5x5-12

A2. Med Ball Scoop Toss 3-5x1-5

A1. Kettlebell Swing 3-5x5-10

A2. Light Sled Sprint 3-5x10-40m

A1. Glute Bridge 3-5x5-10

A2. Bounding 3-5x10-20m

These are just some examples of pairing a force based exercise with a velocity based exercise to help improve power output in the horizontal direction. Doing the complexes in this order enhances the explosive capability of the muscle, otherwise known as post activation potentiation. You can get creative with these and pair all sorts together.