Training for the demands of curved sprinting

While great attention has been placed on how to train linear sprinting, in team sports running in a straight line is only a small part of the game. As players have to evade the opposition, sprinting is more often curvilinear and very rarely linear. Does this mean as coaches we should spend less time sprinting linearly and more time sprinting in a “sport-specific” curvilinear manner?

Quantifying curved sprinting

A recent study with under-18 Premier league soccer players broke down exactly how much curved sprinting takes place in a match depending on playing position. It shows that, on average, 9-21 curved sprints occurred per match and, irrespective of playing position, these curved sprints were an average distance of 13m long and around a 5° angle. While the definition of a sprinting versus mere running is always debatable in research, the speeds here would be considered high speed running by most GPS data speed zones despite the age of the athletes and their curved nature.

To calculate the angle of the sprint, researchers measured from the initial trajectory to the endpoint as shown in the image below. In some cases, players were required to sprint at an angle of up to 30°.

Biomechanical differences in curved sprinting

One of the differences with curved sprinting compared to linear sprinting is that the body leans inwards, as opposed to remaining more upright. Thus, athletes are influenced by centrifugal force and consequently need to counteract this force by producing mediolateral (side to side or frontal plane) ground-reaction force to stay balanced while sprinting. As velocity increases, having the strength and technique to overcome these forces may be an important determinant in curved sprinting performance. Add to this the fact that athletes are often looking over their shoulder or reacting to opposition, and even more biomechanical differences emerge.

Because of these different forces experienced during curved sprinting, coaches may want to incorporate curved sprinting alongside linear sprinting to develop a robust athlete or as part of their return to play protocol.

Testing curved sprinting

I have not yet tested curved sprinting with my own teams, but I have some thoughts on testing that might spur some more ideas on the topic. The change of direction (COD) deficit is a well-researched measure which usually compares the time between a 10m sprint and a 5-0-5 agility test. The greater the difference, the greater the COD deficit.

Potentially, the same calculation could be used comparing a 10-, or 20-meter linear sprint to 1-3 different curved sprinting angles. A simple z-score could be calculated to compare scores within the group and address those with greater deficits or taking a simple median score and ranking upper and lower quartiles could help you choose whether to place a greater emphasis on curved running in some athletes.

Starting with curved sprint training

A good example on how to use curved running can be seen by thinking of how we can integrate it into return to play protocols for injured athletes. Returning to play protocols should cover every potential scenario that could occur during match-play. In doing so, the athlete has proven they are ready to perform with much less risk of re-injury. Often, return to play protocols for a hamstring injury will involve gradually increasing the distance and speed of linear running and sprinting accompanied with various eccentric and isometric hamstring exercises. However, curved sprinting places a unique load on the legs with one leg bearing more load and greater mediolateral forces.

In this case, it would be wise to incorporate curved sprinting into a return to play injury protocol. It could be as simple as starting with:

  1. Short curve accelerations at 5-10° angle alongside the progression of linear speed.
  2. As the athlete progresses to comfortably running at maximum velocity during linear sprinting, curved sprints can be progressed to be longer and more aggressive. The “worst-case scenario” in soccer based on this study is approximately 30° angle which would be a good reference point to train towards before being cleared fully fit to play.

More advanced curved sprint training methods

Training the curved sprint is best placed during your agility focused session. I apply the same rules apply to progressing curved sprints as it does for most other exercises: extensive to intensive. I like to progress from extensive runs (submaximal 20-30 meter curved runs) to intensive sprints (5-10 meter curved sprints) as it fits well with the rest of the agility work.

The following tables shows examples of exercises in each block of a three-block progression. Afterwards the table I discuss the intent of each block.

Block 1 Block 2 Block 3
Extensive agility circuit Extensive open chain Intensive Open Chain
Example circuit: Repeat the following exercises 2-3 times in a continuous fashion, walking between drills.

  1. Single shuffle 20-30m each way
  2. 180° COD (5m in, 5m out)
  3. 45° Step/Cut (5m in, 5m out)
  4. Curve run 20-30m @ 70-80% speed
Example: Gauntlet runs Examples:

Block 1: extensive agility circuit

The extensive agility circuit lets the coach drill the technical nuances of COD in a closed, non-reactive environment. Secondly, it addresses specific work capacity in COD maneuvers which are rarely addressed during “normal” conditioning sessions which can help prepare soft tissue for the more intense COD work to come.

Block 2: extensive open chain

I still classify this as extensive as it can be performed either extensively or up to 100% speed. The end of the Instagram video by Tom Farrow shows a small gauntlet drill. You can perform this with more players and longer distances to make it more extensive. The general rule is the more densely populated the area, the slower the drill will be. If there’s too many people, you’ll start to see less swerving and more stepping. I’ve gone as many as 7-8 players in a 30-40m long grid at 10m wide and found there’s still plenty of room to swerve.

Block 3: Intensive Open Chain

This is where you can have all the fun creating different scenarios. The goal is game-like chaos. In the examples linked above, Tom Farrow and Warren Abrams show variations of large chaos style agility drills to promote curved sprinting and reaction. One similarity you see with the drills is the use of a chaser. Even if it’s a simple 1v1 evading drill, adding a chaser discourages slowing down to change direction essentially forcing the athlete to use a swerve or curved sprint maneuver. If you wanted to also allow other steps and cuts, then removing a chaser would allow the freedom to slow down to perform a different evasion maneuver.

 

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Final thoughts

Sprinting in team sports rarely takes place in a linear fashion, therefore speed training should be performed in more than just a linear fashion as well. Curved sprinting is another skill that should be trained not only to develop speed, but overall robustness to running. While research is scarce in terms of the angles of curved sprints in other sports, it would be recommended to use a wide variety as there would be in a match.