Tuesday, April 20, 2010

Multiple Matches, Recovery and Injury Risk

Competitive soccer is a physically and mentally demanding sport. Unfortunately, injuries still occur. While rules are designed to minimize physical contact, injuries still occur. Some are due to contact with another player, others are considered non-contact and some result from overuse. Physical and mental fatigue associated with competition and training are thought to increase injury risk. Fatigue can occur within a match and occur over the course of several matches played with minimal recovery. Can this also increase the risk of injury? A new European study suggests that this is indeed the case. Playing matches with only 3-4 days of recovery greatly increases the rate of injuries. In some cases by as much five-fold compared to the first match.

This study originated at universities in France and Norway in conjunction with the Celtic Lab (Celtic FC). It focused on 32 players from a European professional team playing in the UEFA Champions League. Because the international soccer calendar is so congested, competing in the Champions League required the team to play their league matches on a Saturday or Sunday, and then play Champions League matches on Tuesday or Wednesday. This pattern results in a post match recovery period of 72-96 hours (3-4 days).

Players were assigned to two groups, those who had not played a match for six days (single-match) and those who played two matches within four days (multiple-match). During each match, movement analyses were performed using a computerized tracking system. Also, all injuries occurring in these matches were recorded.

Movement patterns did not differ between the groups. Players who played single or multiple matches covered 10-11 km (6-7 miles), sprinted about 250m and performed just over 11 sprints per match.

The major finding was a large difference in the rate of injuries between the two groups of players. The overall injury rate in the multiple-match group was approximately five times that of the single-match group. This was due to greater numbers of moderate and severe injuries while minor injuries were similar. Also, most of the injuries that occurred in the multiple-match group were linked to overuse.

As for specific injuries, the incidence of knee and ankle injuries was about three times greater in the multiple-match group compared to the single-match group. Ligament and meniscus damage was also markedly greater in the players who played multiple matches.

The main conclusion drawn from this study is that when professional teams play multiple matches within a week, the risk of injury is substantially increased. While 72-96 hours may be enough time to maintain physical performance, it is not long enough to maintain a low injury risk. The authors speculate that both mental and physical fatigue may have played an important role in the multiple-match group’s injury rate. Earlier studies show that such a short recovery period is not sufficient to restore muscle force, sprint speed and agility. It is possible that players competing with minimal recovery suffered from some form of fatigue even though movement patterns were not affected. Muscle strength and proprioception are key factors in stabilizing both the ankle and knee. If these are not fully recovered by the second match, both joints could be at risk of injury.

Based on their results, the researchers emphasized the need for adequate post-match recovery. Both physical and mental recovery is essential to being prepared for the next match. Nutritional recovery is also critically important. Without proper recovery, repeated matches can lead to physical fatigue, mental burnout, lack of concentration and reduced motivation, all risk factors for injury.

The investigators also emphasize the need to player rotation during competitions with a short recovery period. By limiting individual playing time, fatigue can be minimized, mental stress reduced and injury risk lowered.

U.S. college and high school teams often play multiple matches within a week. Sometimes matches may be separated by as little as 48 hours. Also, youth teams often play multiple matches with less than 24 hours recovery. Are these players also at risk of injury? A key point to remember is that this study focused on a European professional team playing at the highest level not youth players. The effects of multiple matches on youth players may be different. However, the recommendations made by the authors to reduce injury risk should be taken to heart. First, player rotation should be used. Given that most U.S. matches allow free substitution and allow players to re-enter the match, liberal substitution could limit fatigue and reduce injury risk. This is especially true in the second match played. Second, a proper recovery strategy should be followed. A suitable cool down and appropriate post-match nutrition are both essential in preparing for the next match. Use high a carbohydrate diet to replenish muscle glycogen after the initial match. This can improve both mental and physical performance during the second match and reduce injury risk.

Unfortunately, post-match recovery is often overlooked by many players and coaches. The first few hours after a match is a critically important time. Preparing for a second match begins immediately after the first match ends. Neglecting recovery can lead to poor performance and may (according to this study) raise the risk of injury.

Reference:

Dupont G, Nedelec M, McCall A, McCormack D, Berthoin S, Wisloff U (2010) Effect of 2 soccer matches in a week on physical performance and injury rate. American Journal of Sports Medicine, doi: 10.1177/0363546510361236.