What does the research say?
Let’s start with a research study by Shane Malone and colleagues published in the Journal of Science and Medicine in Sport (March, 2018) that looked at high-speed running, sprinting, fitness and injury risk in 37 elite soccer players over a 48-week season.
As part of their routine monitoring program, the session rating of perceived exertion (sRPE) was recorded after training sessions and games. The players also wore a GPS monitor to capture high-speed running (>14.4km/h or about 9mph) and sprinting (>19.8km/h or 12.3 mph).
The players also completed an aerobic fitness test (the 30-15 intermittent fitness test) during each phase of the season.
Over the course of the season there were 75 time-loss injuries where athletes had to sit out a few days; an average of about 2 injuries per player.
When examining the relationship between high-speed running and sprinting with injury, players who completed moderate amounts of high-speed running (701 –750m) and sprinting distances (201 –350m) were at reduced injury risk compared to players in the high and low groups.
But it’s not only the amount of weekly running, there is also a need to consider how the training load changes from week-to-week. Injury risk was also greater for players who experienced large weekly changes in high-speed running (increase of 351 –455-m; and sprint distances increase of 75 –105-m).
Does this mean we should stay away from high workloads?
Nope! As Tim Gabbett has said, “it’s a matter of how you get there”.
Case in point, right here. When players in this study were grouped by chronic training loads, those with ≥2584 AU as determined from weekly sRPE were at significantly reduced risk of injury when they covered a weekly distance of 701-750m of high-speed running compared to those who covered <674m. Compared to players with lower chronic training loads (≤2584 AU) those who covered the same distance of 701 to 750m were at greater risk of injury compared to the reference group of <674m.
And does fitness matter?
All this talk about sprinting distances, but what about aerobic fitness? Does it matter how fit you are? Is it protective against high workloads and injury risk?
Let’s consider that the total sprinting distances are really a cumulation of intermittent bouts of sprint efforts of varying distance and duration. Each of these requires the body to recover before another full out effort.
So yes, fitness matters!
Players with lower aerobic fitness had a greater risk of injury than players with better-developed aerobic fitness. And this also included the ability to tolerate spikes in training load.
What this all means?
- Understand the game demands of your sport (level, athletes, etc.)
- Apply the principle of progressive overload and other fundamental principles (specificity, individualisation, etc.) to a well-rounded strength & conditioning program to physically prepare athletes for the demands of the game.
- Consider the sets-reps-distance of pre-season conditioning sessions.
- Develop intermittent aerobic fitness as it allows players to tolerate higher running volumes and changes in running volumes at reduced risk of injury.
- Coaches should aim to expose their players to periods of training that offer the ability for players to attain both high speed and maximal speed such as large area small-sided games or linear running drills that offer the potential for athletes to achieve these speeds (this should be implemented weekly).
- Build up to higher chronic training loads that will allow players to the exposed to increased volumes of running at reduced risk of injury.
- Monitor the training load using sRPE and/or GPS during training sessions.
- Avoid large spikes (+10-15% or more) in weekly training load.