HIIT Training: High-Intensity Interval Training
Nowadays, high-Intensity Interval Training (HIIT Training) is viewed as one of the most effective ways of improving the endurance capacity of the players.
Muscle injuries are one of the most occurring injuries in team sports. Together with the relatively long recovery time and high reoccurrence rate, preventing these injuries is of utmost importance. As we have discussed in a previous blog, improving the hamstring strength of the players may reduce the number of hamstring injuries in your team. However, hamstring strength isn’t the only factor that reduces the incidence of muscle injuries. Preparing your players for the high demands on the muscles for peak speeds may be another way to reduce the risk of injury.
High speed running (>90% of the maximal speed) is an important quality for performance in team sports. With these high-speed actions, players are able to gain an advantage in attacking and/or defensive situations. However, it is during these actions that most muscle injuries occur because of the high load on the muscles. To prepare the players for these high muscle demands, one might think that it is important to expose the players to high loads of high-speed actions during training. Although, research has shown that excessive exposure to high-speed actions actually increases the risk of muscle injuries. So does that mean that we need to protect the players against injuries by not exposing them to high-speed actions during training? Following the AC-ratio theory, which highlights preventing spikes in workload, that does not seem a responsible way of training periodization.
Another study looked into the relationship between peak speed exposure and injury risk by taking the chronic load (i.e. the average weekly load of the last 4 weeks) into account as well. They found that players who were exposed to >90% of their maximal velocity at least once a week had a reduced risk of muscle injury compared to players who weren’t exposed to such peak speeds. It was also observed that for players with a high chronic load, a moderate amount of peak speed exposures (i.e. 6-10 exposures a week) was found to be protective against muscle injuries. However, the same amount of peak speed exposure resulted in an increased risk of injury for players with a low chronic load (i.e. less fit players or players returning from an injury).
So how do these scientific findings translate to your training practice? Based on the first result, it is advised to expose your players to peak speeds (>90% of the maximal speed) at least once a week during training. One might think of integrating a sprint exercise during training. To make sure that the players reach their peak speed, longer sprint exercises (e.g. 40m sprint: 30m maximal sprint, 10m deceleration zone) are the most suitable for this purpose. But, you do not want to expose your players to these speeds the day before a match. Hence, it is advised to plan this sprint exercise 3 or 4 days before the match.
Based on the second finding of the study, you should be careful with exposing players with a low chronic load to peak speeds. Players who return from an injury or players with low chronic loads (e.g. players with a lower fitness level or regular non-starters) should not be exposed to high amounts of peak speeds (i.e. < 6 times a week). Before they are able to handle these higher amounts of peak speed actions, you need to improve their chronic load. Exposing the other players to excessive amounts of maximal speed actions (i.e. > 10 a week) might also increase their risk of injury as well. Hence, managing the amount of peak speed exposures is of utmost importance for injury prevention.
Performing peak speed actions during a match will result in advantages in defensive and/or attacking situations. However, muscle injuries often occur while performing these type of actions. Because of this, you need to prepare your players for the high muscle demands of these actions. Exposing your players to peak speeds (>90% of the maximal speed) during training sessions is one of the ways to do this. But you need to be careful with the amount of peak speed actions you expose your players too. For the fit players in your team, a moderate amount of peak speed actions (i.e. 6-10 actions a week) will have a protective effect against muscle injuries. For regular non-starters or players returning from an injury, it is advised to be more careful (i.e. <6 actions a week). For these players, it is more important to improve their overall fitness (i.e. chronic load), before increasing the amount of peak speed actions. Hence, peak speed exposure can be a ‘vaccine’ against muscle injuries. But if not managed in the right amounts, it might also be the cause of these injuries!