I have been working as a fitness coach with elite level soccer players for 15 years.  In that time, the one physical ability that seems to always have been of the highest importance to players, parents, and coaches alike, is running speed. Unfortunately, running speed – and how to train/improve it correctly – is probably also the most misunderstood physical ability in soccer.  This 3-part article will provide a detailed summary of running speed and how to train to improve it.  In Part 1 last week, I provided  a definition of running speed, list the phases of a sprint in sports, and discuss what the scientific literature has to say about different methods of speed training.  This week, in Part 2, I will discuss the physiology of speed training, including best practices to maximize training effect while minimizing training volume.  Finally in Part 3, I will shift focus to the biomechanics and specific coordination aspects of running speed.

Running fast and sprinting is, by definition, an anaerobic activity.  This means that the intensity of the exercise (running/sprinting) is so high that the body cannot deliver energy to the muscles through the use and metabolism of oxygen (the aerobic system) and as a result, the anaerobic energy system must produce the energy needed to perform the runs/sprints.  The primary anaerobic energy system used in sprinting in soccer is the anaerobic a-lactic system, because this system provides energy for high intensity work lasting from 0-10 seconds (basically the average duration of a sprint in soccer).  The system is termed “a-lactic” because there is enough rest between sprints/high intensity runs to avoid the production of lactic acid, which is a painful by-product of high intensity exercise and not something that soccer players want to deal with.

The actual sources of energy in the anaerobic a-lactic system are 2 different high-energy compounds, adenosine tri-phosphate (ATP) and creatine phosphate (CP) located within the exercising muscles.  Without getting into all of the details, it is important to know that as soccer players begin training or playing, they will start to perform high intensity runs and sprints, and when this happens, they will start to deplete the stores of ATP and CP in their muscles.  When muscular ATP and CP stores get too low, muscular strength and power decrease significantly, and the only way to recover this strength and power is to rest, in order to allow the body to replenish its ATP and CP stores.  Interestingly, the recovery of muscular ATP and CP is dependent not on the anaerobic system, but rather on the aerobic system.  This means that soccer players who have a high aerobic capacity (better endurance) will be able to replenish their stores of muscular ATP and CP faster, and thus they will be able to recover better between fast runs and sprints, and eventually to perform more runs and sprints throughout a training session or match.

While the information presented above may seem complicated, having a good understanding of the physiology of sprinting in soccer is essential for proper speed training to be planned and executed.  The most common mistake made by coaches and fitness coaches conducting “speed” training sessions with their players is that they do not allow the players enough rest between repetitions to facilitate the replenishment of muscular ATP and CP stores.  When this type of “speed” training (with insufficient rest periods) is used, the athletes end up running at significantly lower speeds than their maximal capacity because, as mentioned previously, when muscular ATP and CP stores get too low, muscular strength and power decrease.  Thus, the end effect of not giving players enough rest between sprints in training is that they actually end up training to be slower, not faster.

So how much rest between sprints is enough?  The easiest way to explain planning rest periods between high intensity running and sprinting is to us a “work-to-rest ratio’” which describes the ratio of time spent “working” (running) to time spent “resting.”  In general, optimal recovery of muscular ATP and CP can occur with a minimum work-to-rest-ratio of 1:6.  This means that if a sprint lasts 2 seconds, then 2 x 6 = 12 seconds of recovery is necessary before the next sprint; if a sprint lasts 5 seconds, then 5 x 6 = 30 seconds of recovery is needed, etc.  Bangsbo et. al. (2006) provided a good review of the best way to structure speed training session, including optimal work-to-rest-ratios, as part of a weekly periodization plan for a professional soccer team.

Ultimately, improving running speed in soccer can only occur if players train by running/sprinting at or very close to their maximal capacity.  Training at or near maximal capacity, in turn, can only occur if players are given enough recovery between repetitions of runs/sprints to allow for replenishment of muscular ATP and CP stores.  Coaches and fitness coaches who wish to improve their players’ running speed must have a good understanding of the physiology of speed in soccer, and plan the work-to-rest ratios in their training accordingly.

I’d love to hear your thoughts about this topic.  Drop me a line here to get the conversation started.

I have been working as a fitness coach with elite level soccer players for 15 years.  In that time, the one physical ability that seems to always have been of the highest importance to players, parents, and coaches alike, is running speed. Unfortunately, running speed – and how to train/improve it correctly – is probably also the most misunderstood physical ability in soccer.  This 3-part article will provide a detailed summary of running speed and how to train to improve it.  In Part 1, I will provide a definition of running speed, list the phases of a sprint in sports, and discuss what the scientific literature has to say about different methods of speed training.  Next week, in Part 2, I will discuss the physiology of speed training, and finally in Part 3, I will shift focus to the biomechanics and specific coordination aspects of running speed.

Running Speed: Definition:

Running speed is the product of stride length and stride frequency.  Stride length refers to how long the running stride is, whereas stride frequency refers to how quickly the legs move over a given distance.  In general, an improvement in stride length and/or stride frequency should result in an improvement in running speed.

Improving Stride Length:

Stride length can be improved by making muscles bigger/stronger (strength training) and also by making them more powerful (power training).  Strength training exercises like squats, lunges, and dead lifts, are simple and effective ways to make the muscles bigger and stronger, and numerous studies have demonstrated that resistance training programs that include these exercises can improve running speed in soccer players (Silva et. al., 2015).  Power training includes explosive lifting exercises (like power cleans or hang cleans); plyometrics (jumping and bounding exercises aimed at speeding up the time the foot is in contact with the ground); and also resisted running exercises (sled pulls, elastic loading devices, or incline running).  Combining explosive lifting with plyometric training and resisted sprinting has been shown to be effective at improving both speed and jump height in post-adolescent soccer players (Lloyd et. al., 2015).  Sled pulls have also been shown to be effective at improving short distance sprint speed in soccer players (Martinez-Valencia et. al., 2015).  At Soccer Fitness, we have used high speed/high incline treadmill running to improve stride length.  In one of our recent studies we were able to demonstrate an improvement in 10, 20, and 35 metre sprint times in elite female soccer players following a high speed/high incline running treadmill repeated sprint training protocol (Bucciarelli et. al., 2014).

Improving Stride Frequency:

Stride frequency, as opposed to stride length, is a bit more difficult to train for.  Training to improve stride frequency must involve some type of assistance provided to the runner in order to make the legs move more quickly that they can voluntarily (commonly termed “over-speed training.”).  Typical/traditional methods of over-speed training have involved downhill running (which uses the force of gravity to assist the runner) or elastic loading devices attached to a training partner (which use the force generated by the partner, as well as the stretch in the elastic loading device, to assist the runner).  Assisted sprint training using an elastic loading device has been shown to improve short-distance (5-10 metres) running speed in elite level soccer players (Upton, 2011).  At Soccer Fitness, we have used a high speed running treadmill with an un-weighting harness as a means of over-speed training, and we recently finished a study that demonstrated a significant improvement in 10 metre running speed following a training protocol with this equipment (Bucciarelli et. al., 2015).

Phases of Sprinting and Application to Training:

Thus, a combination of strength training and power training (to improve stride length), and over-speed training (to improve stride frequency) can be used to improve running speed in soccer players.  But what actual part of a sprint in soccer is affected by what specific types of training?  To answer this question, an understanding of the different phases sprinting. is required.  There are 4 phases of a sprint in soccer, as well as in any other sport:

1. The start phase: the phase where the athlete begins sprinting (could be from a static start or a “flying” start)
2. The initial acceleration phase: the first 5-10 metres of the sprint
3. The carry-over to constant-speed phase: the period from the 15 to 30 metre point of a sprint, when the player reaches top speed
4. The deceleration phase: where the player begins to slow down/stop (this phase will not be discussed in this article).

The application of different types of speed training with the goal of improving these different phases of sprinting in soccer is where most coaches and fitness coaches make errors.  This is typically because of a failure to understand which specific phase of sprinting is affected by which specific type of training.  Strength training, and some types of power training (including explosive lifting, plyometric training, and resisted sprinting with sleds) are basically only effective at improving running speed in the start and initial acceleration phases of sprinting.  In the start and initial acceleration phases, athletes are in a very low position, and the types of exercises that mimic this low position and add resistance to it (squats, power cleans, sled pulls) are the most effective at inducing improvements in the execution of movement from the position.  Incline running, on the other hand, can be effective at improving the carry-over to constant-speed phase of sprinting, because this phase requires athletes to be in an upright position, with maximal range of motion in the hips and knees.  When an athlete sprints up a hill or on an incline treadmill, they can maintain an upright posture, with the added resistance to the running movement coming from the incline itself.  Over time, this leads to athletes developing the ability to overcome resistance while running in an upright posture, which translates a lot better into the carry-over to constant-speed phase of sprinting, an improvement which is impossible to achieve when adding resistance to an athlete in a low position.  The absence of evidence linking strength training, explosive lifting, or sled pulls to improvements in longer-distance sprints (past the initial acceleration phase) supports the argument that these training methods are not likely to cause improvements in that phase of sprinting.

Summary:

Coaches and fitness coaches of elite level soccer players should always try to use a science-based approach when devising speed training workouts for their athletes.  In order to improve soccer players’ speed through all phases of a sprint. a wide range of exercises and training methods must be selected.  Each of these exercises and training methods should be undertaken with a full understanding of which particular phase(s) of sprinting they will affect and (hopefully) improve.  Failure to include exercises that focus on specific phases of a sprint will likely result in a lack of improvement in running speed during that particular phase.

I’d love to hear your thoughts about this topic.  Drop me a line here to get the conversation started.