Discussion
The main purpose of this systematic review was to synthesise postmatch recovery time courses of physical performance tests and relevant biochemical markers in team ball sports. The main finding is that physical test performance (eg, CMJ height and sprint time) returned to baseline after 48 hours in most studies.10 19 22 23 27 32 For the biochemical tests, higher variability within and between studies and tests is shown. In 14 out of 19 studies, CK returned to baseline after ≥72 hours10 22–24 37 38 or did not decrease to baseline within the times of measurement.6 22 24–26 28 33 35 37–40
Performance tests: role of type of sport, exertion and playing level
CMJ height was the most used performance test among the included studies. Players needed at least 48 hours to return to prematch values on this test, with the exception of one study.21 Sprint time was also used often as an indicator of recovery. Recovery time of sprint ranged from 24 to 96 hours. CMJ height and sprint time were measured only in male players in the included studies and ES were small to moderate. In the literature, the validity, reliability and sensitivity of performance test were subject to debate.44 For example, the value of jump height for measuring recovery is limited. Rowell et al14 recently showed that flight time:contraction time is a more sensitive measure of recovery. Although small within-player variation (coefficient of variation (CV) <5%) and high intraclass correlation coefficient (ICC) are reported for the CMJ and sprint tests,45–52 the included studies showed CVs up to 12.8% and 8.2%, respectively. Changes exceed normal variation and thus are relevant.
For CMJ height, one explanation for the length of recovery time courses can be type of sport. Our results indicate relatively longer recovery time courses for basketball in comparison to other team ball sports. One basketball study needed more than 48 hours to reach non-significant values.25 This can be confirmed by another basketball study that reported 96 hours.53 The longer recovery time courses can be explained by the high number of jumps performed during basketball matches.12 25 54 55
For sprint time, duration of recovery time courses can be explained by type of sport, duration of exercise and type of exertion. Two out of four soccer studies reported that more than 72 hours was needed to recover to baseline values.22 23 The other types of sports, basketball25 and handball,19 showed shorter recovery time courses (eg, between 48 and 72 hours). Variability in the duration of total playing time between soccer (2×45 min), basketball (4×12 min) and handball (2×30 min) is evident. It might be expected that longer duration of exercise causes longer sprint recovery time courses. Furthermore, in contrast with soccer, basketball and handball are influenced by interruptions (eg, timeouts, time between quarters, match stops) and the use of substitutions. More short-term recovery in sprint time can be expected when performing these intermittent sports compared with soccer.
Finally, for both CMJ height and sprint time, physical fitness indicated by differences in competition level might explain variability between study results.56 One study with non-elite players showed a strong decrease in CMJ height directly postmatch.27 This is in accordance with Magalhães et al’s 57 study that showed a strong decrease followed by a long recovery period (>72 hours) in second and third division soccer players. The sharp drop in jump height and subsequent longer recovery time may indicate that lack of physical fitness in these amateur players affects recovery. A similar pattern is seen in sprint time. This was relatively high at the lower level in comparison to the elite level.57 58 Players played second and third divisions57 and secondary division,58 respectively. In these studies, sprint time also needed to recover longer.
Biochemical markers and variability of recovery kinetics
The most used biochemical markers to monitor recovery were CK, C and T. Except for one study,35 strict protocols were set up for measuring these biochemical markers. Players followed a controlled diet, were measured at exactly the same times of the day and were excluded from heavy exercise other than the match during the measurements. Although CK (ES were large to very large) shows high variability (CV >25%) between individual players and poor sensitivity,52 59–62 the included studies showed CVs up to >700%. This exceeds normal variation which makes it relevant to discuss. For C and T high ICCs are reported in standardised conditions.63
CK helps with the synthesis of ATP in muscles and increases after a match as a result of muscle damage.64–66 All studies that investigated CK took blood samples after a match. Interestingly, 11 studies reported much higher peak values for CK concentration6 10 22–24 33 34 37–39 41 than other included studies.19 25 27 28 35 36 A possible explanation for this might be type of sport. High-peak values of CK were all found in soccer or rugby studies. The other studies represent more variation in type of sport. This suggests that soccer and rugby may be physically more demanding and muscle damage caused by, for example, distance covered, accelerations and high impacts is higher.38 67–69 According to the literature this cannot be concluded unambiguously.70 However, taking competition level, position on the field21 71 72 and type of methodology (eg, global positioning system, time-motion analyses)73 74 into account, it complements studies investigating player load or recovery in these sports.4 11 70 75–79
Three studies in soccer and rugby reported lower peak values.27 28 35 Deviation in one of these studies27 might be explained by the fact that samples were taken after a simulated match, while in all studies that reported high-peak values, samples were taken after an official match. Possibly, next to lower physical exertion during simulated matches,80 lower peak values of CK can be expected.
C is an important catabolic stress response hormone and is considered to be increased as a result of playing a match.64 81 The results of the included studies showed a high variance in time needed for C concentrations to decrease to baseline values. However, most soccer or rugby studies needed at least 48 hours to recover.10 29 37 38 So, it seems that in line with CK, also C is responsive to higher loads in soccer and rugby and this causes longer recovery times. This is in accordance with previous studies reporting a greater C response in higher intensity and longer duration.82 83
T is an anabolic hormone that stimulates glycogen synthesis and protein signalling which is needed for tissue repair.64 84 85 In general, an unclear pattern of T responses is demonstrated by the included studies. This is in line with previous reported differences between rugby and other sports by Cormack et al20 that support the high demands of this sport. In our systematic review one soccer and one rugby study reported higher T levels directly postmatch and returned to baseline within 18–24 hours.35 38 Another two studies showed a decrease immediately postmatch followed by an increase to baseline within 14 hours33 or delayed higher T levels in the following days42 in rugby players. Three studies showed a prolonged decrease that was interpreted as unclear and trivial by the authors,20 an increase to baseline after 60 hours29 or deviation still 48 hours postmatch.26 Finally, in four studies no significant change in T concentration was found.10 19 23 36 Individual variability in T responses might explain the differences found in the studies.
Practical perspective
Overall, results of this systematic review suggest that team ball sports players need, in most cases, at least 48 hours to perform at the same level as prematch. Some biochemical markers needed to return to baseline values even longer. Especially, CK is increased for ≥72 hours postmatch. This is the case for all team ball sports. However, CK reached higher values in soccer and rugby. In addition, for soccer and rugby it took longer to return to baseline for sprint performance, CK and C in comparison to other team ball sports.
The slow decrease in CK suggests that, although performance is already at prematch values, the muscles need more time to recover. This is an important finding that should be kept in mind working as a practitioner or support staff in daily practice with team ball sport players. In the decisions-making process of determining adequate recovery, coaches should distinguish short term and long term under recovery and consider context such as stage of season. If, for example, performance is unaffected during a tournament, but biochemical indicators are, one can still decide to play in optimal formation. This is especially true when full recovery is possible after the tournament and cumulative fatigue is avoided. However, if biochemical markers indicate poor recovery without upcoming phases of rest, then coaches could implement recovery strategies or prescribe rest within the training schedule. This seems important to avoid the ongoing process of insufficient recovery that is not directly demonstrated by performance tests. Based on practical perspective and cost-benefit arguments, one could decide to only perform biochemical analyses with clear indication of ongoing insufficient recovery during, for example, fixture congestion. Commonly used performance tests with their recovery time courses will then, in all likelihood, deviate from biochemical markers that could indicate more precise muscle damage.
Finally, there is a need to understand individual players and their recovery profiles. Recovery is highly dependent on both variation in load that players are exposed to during matches (eg, position dependent and variation of time during matches) and individual capacities (eg, aerobic and anaerobic).24 32 These capacities determine how players respond to the match load and play an important role in their ability to recover from that load. Therefore, it is crucial to monitor individual match load and recovery.
Strengths and limitations
This systematic review provides extensive insight in postmatch physical recovery in team ball sports with at least two postmatch measurements compared with prematch values. This satisfies the lack of a valuable overview of postmatch recovery time courses. Despite studies that not reported data in numbers in tables and/or text were excluded, results of these studies are affirmative with the results found.53 57 58 79 86–88
A limitation of this review is that it does not provide information on the available tests and processes of psychological recovery. It has been stated that a disturbed balance between both, physiological and psychological, stress and recovery can lead to maladaptation, and performance can be directly influenced by a poor mental state.89 90 However, the aim of this systematic review was to understand and compare objective, single-construct, recovery measures after matches.
Future research
Twenty-three out of 28 included studies investigated recovery in soccer or rugby. Unfortunately, studies in other sports were not as extensive as the soccer or rugby studies. Therefore, it is more difficult to get an indication of recovery of players from these sports. High-level original research is needed to get more insights in postmatch recovery in these sports. Furthermore, studies using recovery strategies or interventions were excluded from this review. Future studies should also evaluate the effects of these recovery strategies (eg, active recovery, sleep, mental recovery) on an individual level in the practical setting of team ball sports.