Monday, November 25, 2013

Match Analysis and the Recovery Process

Match analysis has become an important tool in assessing team performance. Knowing team and opponent tendencies, individual player performance indicators, and markers of fatigue can help the coach or manager formulate match strategies and pinpoint team and individual weaknesses. Thus, it is not surprising that sport scientists are very interested in how match analysis can be used to improve their team and move them up the league table. In a new study, researchers at the Université Lille Nord de France and Lille Métropole Football Club took a different look at match analysis. They compared match analysis data to various performance indicators measured during three days of recovery. They found several interesting relationships between various player movements and prolonged decrements in physical performance. Their results have important implications for understanding the recovery process as well as preventing potential injury.

Match analysis was performed during four competitive matches to establish various playing actions completed by the players. At 1, 2 and 3 days following the matches, the players provided subjective ratings of fatigue and muscle soreness. They also underwent several physical tests of strength, sprint, and power performance. Data obtained at each recovery interval were compared to baseline measurements taken earlier in the season. During the post-match recovery period, players continued their regular training routine but were asked to avoid recovery treatments such as ice baths, compression garments and massages. 

During the three-days after the match the players reported several perceptions. They felt a greater sense of fatigue at the 24-hour mark that subsided by 48 and 72 hours. They also reported increased muscle soreness across all three post-match days. This sensation of muscle pain and discomfort was associated with increased blood creatine kinase levels, a key indicator of muscle damage.

In terms of physical performance, power output was decreased by 5-6% over the course of the recovery period. Both peak sprint speed and vertical jump measures were depressed for up to 72 hours post-match. Also, hamstring strength in both the dominant and non-dominant legs were reduced for the duration of recovery. The researchers found between 6 and 8% reductions in dynamic strength of these muscles.

Match analyses showed that the changes in muscle soreness were most closely linked to the number of short sprints performed during the match. Fatigue and physical performance were linked to the number of hard directional changes and the number of tackles executed. This is not surprising. Sprinting and changing directions requires rapid acceleration and deceleration. Both of these actions require forceful concentric and eccentric muscle contractions. We’ve known for years that eccentric or lengthening contractions leads to both fatigue and delayed onset muscle soreness. However, this is the first study to link movement patterns and player actions during a match to the degree of soreness and physical performance decrements.

The finding that hamstring strength was depressed for up to 72 hours post-match has important implications for the recovery process as well as the risk of anterior cruciate ligament injury. As we’ve discussed previously on the SSO, ACL injuries is a growing problem. Recognizing, understanding and correcting risk factors can go a long way in preventing injuries. We’ve known for years that both weak hamstrings and muscle fatigue increase injury risk. When various movements stress the ACL, the hamstrings contract to help stabilize the knee. With fatigued or weakened hamstrings, this aspect of stability is reduced and the potential for sustaining and injury increases.

This study shows that hamstring muscle fatigue may persist for up to 72 hours after a match. Many college, high school and youth club schedules require multiple matches to be played with as little as 24 hours of recovery. The Atlantic Coast Conference has adopted a Thursday and Sunday schedule of women’s matches, leaving 72 hours of recovery from the first match to the second. Other teams and conferences used a more congested format, a Friday and Sunday schedule. Based on the current research article, it is quite possible that many players are not fully recovered by the start of the second match. That is, hamstring strength may remain depressed, raising the risk of ACL injury. This may be particularly true if the preceding match required players to execute an abnormally high number of short sprints and changes in direction.

Unfortunately, there is little information on injuries occurring during this schedule of matches. And, to be truthful, we don’t know if more injuries occur during the 72 hours after a difficult match. Despite this, coaches should take caution and consider this information when faced with a congested calendar. At the very least, coaches should be aware that player performance may suffer for up to 72 hours after a difficult match. Strategic use of player substitutions could reduce the number of key player movements (sprints, direction changes) and may be able limit fatigue in the initial match. Targeted exercise recovery regimes may also speed the recovery process between matches. In this study, players were not allowed to use treatments such as ice baths, compression garments or massage. While the research is not completely clear on how well these techniques actually aid the recovery of muscle force, some argue that they may offer some benefit. Finally, research is clear that a proper nutritional recovery strategy can enhance the recovery process. High carbohydrate foods and beverages containing some protein taken immediately after the match are critically important to recovery. Continuing the process with nigh carbohydrates meals and plenty of fluids is important as well.

Understanding how the physical demands of the match can impact subsequent performance is important over the course of a season. And, recognizing how a strategic recovery process can affect both performance and injury risk can go a long way in the team having a successful season.

Reference

Nedelec M, McCall A, Carling C, Legall F, Berthoin S, Dupont G (2013) The influence of soccer playing actions on the recovery kinetics after a soccer match, Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000293.