RECOVERY TIME OF THE ANTERIOR CRUCIATE LIGAMENT INJURY IN ELITE FOOTBALL
The anterior cruciate ligament rupture (ACL) is a complicated injury for football players.
Traditionally, napping has been viewed as a lazy habit associated with people living in the southern hemisphere. At least this was the opinion shared by many from northern regions of the planet. Where temperatures are cooler, there are fewer daylight hours and environmental conditions discourage the body from sleeping during the day. However, this negative conceptualisation has changed in the last decade, mainly due to the increased use of sleep medications and successive studies that have demonstrated how sleep is a determining factor for learning. A study carried out by the Harvard Medical School, is especially relevant for sports trainers, because it found that a short nap can reinforce the memory of what was learned just as well as a full night’s sleep.
Participants in this study had to work their way through a virtual maze on a computer, making their way through the maze until they successfully found the exit. There were objects, decorative elements and music snippets throughout the maze, all designed to help participants remember the crossings and alternative paths. Five hours later, participants had to repeat the task, in order to assess how well they could remember the correct route. The results showed that participants who had taken a nap in the interval between tasks performed up to 46% better than participants who had not napped. The findings also demonstrated that a very effective method for memorising new learnings was to instruct participants to go to sleep thinking about the task they had just completed.
The key lies in the work carried out by our brain while we are sleeping. Recent memories are moved from the hippocampus and important memories are stored in the neocortex, which provides us with long-term memory. This study demonstrated that a prolonged period of sleep was not necessary for this process to occur: sleep periods did not exceed 40 minutes for any of the participants. Furthermore, researchers noted that this time frame should not be taken as a guideline, as the duration of the nap could in fact be much shorter but still equally effective for learning. What was evident is that a brief period of sleep, such as a traditional siesta, produces benefits similar to that of a full night’s sleep. It is important however that the nap does not exceed 30-45 minutes since, after this time, the brain enters “sleep mode” whereby it would ideally want to complete the 4-5 sleep cycles necessary for proper rest. Interrupting the normal pattern of these cycles means that when we wake up from a nap we may feel worse than when we started sleeping.
These results can be applied to young athletes, through recommendations aimed at reviewing what they have learned as they are falling asleep and encouraging them to take a nap whenever they feel they need to. Sleep reinforces semantic knowledge – the explanation of game tactics, for example – but also procedural memory, for example, the motor skills required to perform a task. Therefore, if the time of day is right, and we want to take advantage of travel time, trainers can consider encouraging athletes to take a nap, first briefly reviewing tactics or other key training factors, match-related information or visualising the match.
FC Barcelona is strongly committed to reinforcing the importance of sleep as an invisible training and to encourage good habits among youth teams, with the Sleep Guide in collaboration with the AdSalutem Institute. The guide includes tips such as not prolonging a nap beyond 30 minutes nor taking one after four o’clock in the afternoon. It also encourages the players to take advantage when travelling to play a match or a training sessions to take a nap.
Irregular sleep, as we have discussed in a previous article, is one of the greatest threats to the performance of adolescents, and a common, worldwide phenomenon that occurs in this age group. Removing the negative connotations associated with napping will not only help to compensate for possible fatigue in adolescents but will also strengthen what they are learning and influence another fundamental factor for athletes: emotional well-balanced. Mood changes, irritability and negative thoughts are all common during adolescence and can be reduced with good sleep habits. Regular naps, when our bodies are asking for it, can have important benefits.
The Barça Innovation Hub team
An article published in The Orthopaedic Journal of Sports Medicine —in which members of the club’s medical services participated— now suggests to consider the detailed structure of the area affected, and treating the extracellular matrix as an essential player in the prognosis of the injury.