Effects of Ramadan Fasting on Health and Athletic Performance Edited by www.esciencecentral.org/ebooks Dr. Hamdi Chtourou Effects of Ramadan Fasting on Health and Athletic Performance Chapter: Injury Rate during Ramadan Edited by: Hamdi Chtourou Published by OMICS Group eBooks 731 Gull Ave, Foster City. CA 94404, USA Copyright © 2013 OMICS Group All book chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. However, users who aim to disseminate and distribute copies of this book as a whole must not seek monetary compensation for such service (excluded OMICS Group representatives and agreed collaborations). 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Cover OMICS Group Design team First published August, 2013 A free online edition of this book is available at www.esciencecentral.org/ebooks Additional hard copies can be obtained from orders @ www.esciencecentral.org/ebooks Injury Rate during Ramadan Karim Chamari1,2*, Monoem Haddad2,3, Hamdi Chtourou2, Christopher Herrera1 and Cristiano Eirale4 1 Research and Education Department, ASPETAR, Qatar Orthopaedic and Sport Medicine Hospital, Doha, Qatar 2 Tunisian Research Laboratory “Sport Performance Optimization”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia 3 University of Jandouba, ISSEP Kef, Tunisia 4 Sport Medicine Department, ASPETAR, Qatar Orthopaedic and Sport Medicine Hospital, Doha, Qatar *Corresponding author: Professor Karim Chamari, Doctor in Exercise Physiology, Research Scientist, Research & Education Centre, ASPETAR, P.O. Box 29222, Doha, Qatar, Tel: (+974) 3318 6096; Fax: +(974) 441 32020; Email: Introduction Injury surveillance studies are an integral part in the efort to protect athletes’ health in various sports activities. Furthermore, injury risk is a major concern for athletes and clubs in terms of health, safety, performance, and cost. Data in scientiic literature must be made available through an efective injury surveillance system, and therefore better knowledge of the factors that afect injury will always be needed. here is also a need to identifying the injury risks and their respective dependent and independent variables, which are expected to difer in each speciic population. herefore epidemiological and etiological injury data for various sport activities need to be captured. Investigations describing injury risk and patterns are usually conducted over seasons of European, Asian or American Leagues [1-3] obviously out of holy month of Ramadan or without taking into account the intermittent fasting occurring during Ramadan. To our knowledge, only two studies [4,5] have focused on the injury-rates of Muslim athletes during the holy month of Ramadan. More speciically, these studies focused on soccer’ injuries in order to improve the knowledge in that ield in view of the preparation for the Olympics 2012 and the FIFA World Cup 2014 being organized during the Ramadan period. In this context, there is a debate on the possible efects of fasting and the other modiications of life pattern during Ramadan on injury risks. he present chapter is therefore focused on the efects of Ramadan on the injury rates in soccer, pending other studies to be conducted in other sport activities. he main aim of the present book chapter is to present and discuss the athletes’ injury rate during Ramadan and its related possible causes. It is hoped that by providing such analysis, coaches and scientists will better understand the impact of Ramadan fasting and choose an eicient planning and manipulation of the player’s internal training load and life-style modiications during the Ramadan period to try to reduce the players’ risks of injuries. Ramadan Characteristics During Ramadan, fasting Muslims do not eat, drink, smoke, or have sexual activities daily from dawn (Sahur) to sunset (Itar). Since the Islamic Calendar is based on the lunar cycle, which advances 11-days each year compared with the standard Gregorian calendar, Ramadan falls at diferent times of the seasonal year over a 33‐year cycle [6]. his implies that Ramadan occurs at diferent environmental conditions between years in the same country [7,8]. Furthermore, depending on the seasonal and geographical conditions, fasting may vary from ~11 to ~18 hours per day. he increased perception of fatigue reported at the end of Ramadan fasting and the combination of intense training with altered carbohydrate intake, hydration-status, and sleeping pattern may place fasting Muslim athletes at greater risk of overreaching or overtraining [12,13] which could result in physical injury speciically overuse injuries [14]. Most previous studies determined whether the holy month of Ramadan has any detrimental efect on performance and cognitive functions, but to our knowledge, only the studies of Chamari et al. [4] and Eirale et al. [5] have examined the impact of the month of Ramadan and its speciic socio-cultural and religious environment on the injury rates of professional soccer players. he irst was a pilot study while the second was a prospective cohort study. Both of them presented results on the injury rates between fasting and non-fasting players within teams before, during, and ater the month of Ramadan in professional football teams during consecutive seasons. Studies Conditions he study of Chamari et al. [4] was carried out during two consecutive seasons to investigate the injury rates senior professional OMICS Group eBooks It is supposed that most Muslim soccer players fast during Ramadan, even if some exceptions are observed. Ramadan fasting is intermittent in nature, and there is no restriction to the amount of food or luid that can be consumed ater dusk and before dawn. herefore, since the international sporting calendar is not adapted for religious observances, and Muslim soccer players continue to compete and train during Ramadan, various studies have determined whether this religious fast has any efect on athletic performance [6] and cognitive functions [9,10]. hese have suggested that only few aspects of physical itness are negatively afected, and only modest decrements are observed when physical performance is considered on the basis of itness testing [6]. he evidence to date indicates that high-level athletes can maintain most of the performance measures during Ramadan if physical training, diet, and sleep are well controlled. Nevertheless, despite this, fasting athletes have reported higher fatigue feelings at the end of Ramadan [6,11]. his could have a possible efect on injury rate during or at the end of the month of Ramadan. 003 soccer players in Tunisia . For this study, fasting status was determined only at the end of the Ramadan month using a personal interview with each player and discrete cross-checking with the player’s team-mates and whenever possible with family members and/or friends. he players were retrospectively organized into fasting and non-fasting groups based on this information. he fasting group consisted of all players who fasted throughout the Ramadan month and the non-fasting group consisted of players who opted not to fast throughout the Ramadan month for both training and match days. All Muslim players who fasted in the study of Chamari et al. [4] had practiced the fast during Ramadan for at least the previous 7 years. Goalkeepers were included in the study. he studied team was competing at the highest level in the Tunisian irst league and also participated in the African Cup of teams (CAF Cup) during the second season of the study. During this study, Ramadan occurred from 10th August to 11th of September 2010 and from 1st to 30th of August 2011, respectively, where the daily fast occurred from ~04 h to ~19.15 h, for a total fasting duration of ~15h 15min. All players were monitored for 4 weeks before Ramadan, for the month of Ramadan (4 weeks), and 4 weeks ater Ramadan in each year. Training loads {using the RPE-method [15], Hooper index [16] {i.e., Sum of individual’s subjective well-being ratings relative to fatigue, stress, delayed onset muscle soreness (especially “heavy” legs), and sleep quality/disorders}, and injuries were monitored in 42 professional soccer players (age, 24 ± 4 years; height, 185 ± 8 cm; body mass, 78 ± 4 kg). he prospective cohort study of Eirale et al. [5] was conducted during 3 consecutive seasons beginning in August 2008 and ending in April 2011 within male professional footballers from the Qatar Stars League (QSL) which is the senior professional irst division football league in Qatar. According to the authors, the number of irst division clubs increased from 10 to 12 ater 2009. In Qatar, the soccer season lasts from July to April. During both of the study of Chamari et al. [4] and Eirale et al. [5], injury data were considered when a player was unable to fully participate in any future soccer training sessions or matches owing to physical complaints [17]. Information about mechanism of injury (contact or noncontact), their etiology (acute trauma or overuse) and circumstances (training or match injury) were documented. In this context, a traumatic injury refers to an injury resulting from a speciic identiiable event, whereas an overuse injury was deined as an injury caused by repeated microtrauma without a single identiiable event responsible for the injury. Recurrent injuries were deined as an injury of the same diagnosis and at the same site, which occurred ater a player’s full return to participation from the same injury within a 2-month period. Injury severity was determined by the number of days of absence from games or training sessions due to injury and was further classiied as mild (i.e., 1 to 3 days), minor (i.e., 4 to 7 days), moderate (i.e., 8 to 28), or severe injury (i.e., >28 days) [17]. During Ramadan, any game time between sunrise and sunset is generally avoided. herefore, during the two studies [4, 5], training sessions and matches were performed at least 2 to 3 hours ater sunset (and thus itar), allowing athletes to adequately replenish and rehydrate before starting sport activity. More speciically, during the study of Chamari et al. [4] training sessions and matches were performed ater dusk (starting at 22h) during Ramadan, while before and ater Ramadan the sessions and matches were scheduled in the aternoon (starting at 15 or 16h) and sometimes in the morning for training (for the days in which 2 training sessions were scheduled, starting at 09.30 h). It has to be noted that these double sessions’ days remained exceptional. Also during the study of Eirale et al. [5], all clubs trained ater sunset during Ramadan in all 3 seasons with absolutely no daytime football activity. Table 1 adapted from the prospective cohort study of Eirale et al. [5], shows the dates in which Ramadan occurred throughout the 3 seasons. Season 2008 to 2009 2009 to 2010 2010 to 2011 Start Date September 1, 2008 August 22, 2009 August 11, 2010 End Date September 30, 2008 September 20, 2009 September 9, 2010 Table 1: Ramadan Time Frame for the three Seasons controlled according to Eirale et al. [5]. Chamari et al. [18] have more monitored ambient temperature, atmospheric pressure, and relative humidity which were measured for each training session (Table 2). he duration of data collection over a 3-year period in the study of Eirale et al. [5] was limitation for this study. Ramadan falls on diferent months of the year over a 33-year cycle because it shits 1 to 2 weeks earlier each year [19]. his seasonal shit impacts the environmental conditions, and the length of the daytime fasting period cannot be controlled. Injury data from Ramadan occurring in all year periods, would permit the elimination of potential bias arising from seasonal variation of injuries, as previously shown in soccer [20]. Before Ramadan Ramadan After Ramadan Year Ambient temperature (C°) Atmospheric pressure (mmHg) 2010 28.83 (1.72) 1012.33 (2.25) Relative humidity (%) 44.00 (5.02) 2011 31.31 (5.38) 1011.38 (3.10) 39.15 (13.61) 2010 27.60 (4.04) 1014.20 (2.05) 55.80 (8.44) 2011 24.50 (1.29) 1014.50 (2.65) 64.50 (6.56) 2010 25.25 (2.06) 1014.00 (3.83) 61.50 (8.66) 2011 28.50 (1.29) 1013.25 (3.10) 63.25 (8.54) Values are mean (SD) Table 2: Environmental conditions, table adapted from the study of Chamari et al. [4]. During the prospective cohort study of Eirale et al. [5], only the training sessions’ duration was recorded due to the study design. However, Eirale et al. [5] supposed that intensity may potentially be adjusted by coaches to avoid injuries, becoming a possible confounding factor. No prospective data collection of actual dietary, sleep habits, body composition, and training characteristics were present in this study. hese factors might potentially have had their inluences and authors recommended to examine them in future studies. On other hand, in the study of Chamari et al. [4], daily individual training load was calculated using Foster’s session-RPE procedure [21]. his method involves multiplying the training duration in minutes by the mean training intensity. As the players involved were all French speaking subjects, the session-RPE scale was based on the validated French translation of the Borg category ratio (CR-10) [18], which converts the player’s perception of efort into a numerical score between 0 and 10. his method has been validated previously in OMICS Group eBooks Monitoring of training loads and overtraining 04 soccer by Impellizzeri et al. [15]. Practically, the player is asked to respond to a simple question – How was your workout? – with the aim of obtaining an uncomplicated response that relects the athlete’s global impression of the workout. All players were familiarized with this scale for at least one month before the start of the study and followed standardized instructions for session-RPE assessments. Each player’s session- RPE was collected approximately 20–30 min ater each soccer training session and match to ensure that the perceived exertion referred to the whole training session and match rather than the most recent (end-of session) exercise intensity [15]. Overtraining syndrome was monitored by Hooper’s Index (Hooper & Mackinnon, 1995). his method is based on self-analysis questionnaires involving well-being ratings relative to fatigue, stress, delayed-onset muscle soreness (especially ‘‘heavy’’ legs), and sleep quality/disorders (Hooper & Mackinnon, 1995). Before each training session and match, the players were asked to rate subjective quality of sleep, and quantity of stress, delayed-onset muscle soreness, and fatigue on a scale of 1–7 in accordance with Hooper and Mackinnon (1995). Hooper’s Index is the sum of the four subjective ratings. Recently, Haddad et al. [22,23] have shown the absence of possible inluence of the Hooper’s Index and duration on RPE in professional soccer. herefore, it is recommended that future studies use both the Hooper’s index and session-RPE method as independent tools to closely monitor the players’ training loads [4]. In that study [4], dietary composition was not assessed but body composition did not signiicantly change over the monitored months. Injury Rates During both studies [4,5] injury rate was calculated as the ratio of the number of injuries per hour of exposure and expressed as the rate per 1000 hours. he irst study [4] has shown that rates of non-contact injuries and overuse injuries were signiicantly higher during training in fasting players during the two months of Ramadan monitored with 84.21% out of total injuries observed, compared with before and ater the holy month with only 22.22% of total muscle injuries in both cases. For these two months of Ramadan [4], the overuse injuries were distributed as follows: muscle spasms (contractures) 43.75%, tendinopathy 43.75%, and muscle strains (one tear at the hamstrings and one strain at the thigh-adductors) 12.5%. he 7 contractures were located at the hamstrings (42.86%), calf muscles (28.57%), thigh-adductors (14.29%), and knee extensors (14.29%). he tendinopathy injuries were located at the thigh-adductors (42.86%) and foot quadriceps (14.29%), with the remaining tendinopathy injuries (42.86%) located at the abdomen and pelvis. he foremost result of the study of Chamari et al. [4] was the absence of signiicant diference between non-fasting and fasting players with regard to general injury rates, while the training overuse injury rates were signiicantly higher during Ramadan than before and ater-Ramadan periods for the fasting players (Table 3). Overall, during the fasting months, only one goalkeeper got one injury in a traumatic training injury (ankle sprain) about three weeks before Ramadan. Before Ramadan + Ramadan + After Ramadan + Fasting Non-Fasting Fasting Non-Fasting Fasting Non-Fasting Injury rate 3.3 (-0.3-6.8) 1.7 (-1.9-5.2) 8.1 (4.5-11.6) 3.9 (0.3-7.4) 4.5 (0.9-8.1) 1.6 (-2.0-5.1) Rate of contact injury 2.7 (-0.9-6.3) 1.1 (-2.5-4.7) 1.3 (-2.3-4.9) 0.7 (-2.9-4.3) 3.4 (-0.2-7.0) 1.6 (-2.1-5.1) 0.6 (-2.2-3.3) 0.6 (-2.2-3.3) 6.8 b (4.0-9.5) 3.2 (0.4-5.9) 1.1 (-1.7-3.9) 0 (-2.8-2.8) Rate of contact injury during matches 1.6 (-0.8-4.1) 1.1 (-1.3-3.5) 0.7 (-1.7-3.2) 0.7 (-1.7-3.2) 2.1 (-0.3-4.5) 0 (-2.4-2.4) Rate of overuse injury during matches 0 (-1.3-1.3) 0 (-1.3-1.3) 1.2 (-0.1-2.4) 0 (-1.3-1.3) 0.5 (-0.7-1.8) 0 (-1.3-1.3) Rate of contact injury during training 1.1 (-0.9-3.1) 0 (-2.0-2.0) 0.6 (-1.4-2.6) 0 (-2.0-2.0) 1.3 (-0.7-3.3) 1.6 (-0.4-3.5) Rate of overuse injury during training 0.6 (-1.1-2.2) 0.6 (-1.1-2.2) 5.6 b (4.0-7.2) 3.2 (1.5-4.8) 0.5 (-1.1-2.2) 0 (-1.6-1.6) Rate of noncontact injury + each period consisted of 4 weeks respectively in each of the two studied seasons. b signiicantly higher than before and after-Ramadan. Note: values in bracket are 95% conidence intervals. Table 3: Comparisons of injury rates in fasting and non-fasting players for the two monitored seasons [4]. Total exposure during Ramadan was 17 009 hours, 15 237 hours for Muslim soccer players. Match exposure was 1695 hours (included 1442 hours for Muslims) and training exposure was 15 313 (included 13 795 hours for Muslims). Mean monthly exposure in the nonRamadan period was 12 285 hours (included 10 875 hours for Muslims). From the 527 players assessed during the study of Eirale et al. [5], 403 reported at least 1 injury, with a total of 826 injuries (364 during matches and 462 during training sessions), leading to injury rate of 4.97/1000 hours (95% CI, 4.6-5.3). Match injury rate was higher than training [16.4/1000 hours (95% CI, 14.8-18.2) vs 3.1/1000 hours (95% CI, 2.9-3.5); P < 0.001, respectively]. A total of 77 injuries were observed during Ramadan, of which 36 (47%) occurred during match play and 41 (53%) during training sessions. Figure 1 shows total, match, and training injury incidence during Ramadan and out-Ramadan periods according to Eirale et al. [5]. During this study, no signiicant diference was found between the 2 periods monitored (i.e. Ramadan and out of Ramadan). hese results are consistent with those shown by Chamari et al. [4]. Obviously, injury rates during matches was signiicantly higher than training rate during both Ramadan and out-Ramadan periods during the study of Eirale et al. [5]. OMICS Group eBooks In the study of Eirale et al. [5], total exposure for the 3 consecutive seasons was 164 434 hours (included 145 734 hours for Muslims); match exposure was 22 206 hours (included 19 242 hours for Muslims); training exposure was 142 230 hours (included 126 492 hours for Muslims). Here it has to be noted that Eirale et al. [5] named ‘’Muslims’’ the fasting players and that non-Muslims were non-fasting players. 05 Figure 1: Injury incidence with upper 95% CI during training [5]. Total, match, and training injury rate during the Ramadan and out-Ramadan months, considering Muslim and non-Muslim soccer players separately are shown in Figure 2 according to Eirale et al. [5]. Total, match, and training injury rates were not diferent for Ramadan compared to the rest of the season in both Muslim and non-Muslim players. Figure 2: Injury incidence with upper 95% CI in Muslim and non- Muslim groups for training and matches during Ramadan and out- Ramadan periods [5]. It is spectacular to know that a signiicantly total higher risk of injury was observed during the study of Eirale et al. [5] with NonMuslim soccer players compared to Muslim soccer players throughout the season (i.e., both during Ramadan and out-Ramadan periods). his increase of injury rate was only demonstrated during matches, not during training settings. It may be speculated that these indings are related to age, an intrinsic risk factor, which is known to afect the risk of injury in footballers [24-26]. Indeed, the non-Muslims (29.2 ± 4.6 years) were on average older than Muslims (26.5 ± 4.6 years) in the study of Eirale et al. [5]. Eirale et al. [5] have shown that the probability of match injury among non-Muslims was the highest in Ramadan (3 times high risk of match injury) and the 2 consecutive months ater. As suggested by Eirale et al. [5], these results above can be explained by the possible inability of non-Muslim players to cope with changes in the circadian rhythm imposed by the altered sleep/wake schedule during Ramadan. Because most of the non-Muslim soccer players were foreigners, another possible explanation could be the complexity they face with adapting to the hot and humid climate in Qatar, which may constitute as another risk factor for injury. Indeed, the hot climate in Qatar usually falls within the months of May and September, consequently, including the Ramadan months in the study of Eirale et al. [5]. However, these considerations remain a hypothesis because climate data were not collected and, therefore, cannot be excluded as a potential confounding factor. Non-Muslim soccer players may be more susceptible to injury, as they are unable to adjust to the general change of social life during the holy month of Ramadan in Qatar as suggested by Eirale et al. [5]. Moreover, these authors have shown that injuries deined as moderate were the most common for both Muslim and non-Muslim players during Ramadan and out-Ramadan periods. Nevertheless, no signiicant diference was observed in injury incidence between the 4 classiications (mild, minor, moderate, and severe injuries). Likewise, no signiicant diference in injury rate was found when comparing contact and non-contact injuries, overuse and traumatic injuries, and injuries and reinjuries during Ramadan and out-Ramadan periods. OMICS Group eBooks According to Eirale et al. [5], Muslim players demonstrated a uniform rate throughout each month of the Islamic calendar. Adjusted odds ratio of injury among non-Muslims compared with Muslims was 3.7 (95% CI, 1.7-7.9, P = 0.001) during Ramadan (ninth) month, 2.4 (95% CI, 1.1-4.9, P = 0.021) during the 10th month and 2.7 (95% CI, 1.2-5.8, P = 0.013) during the 11th month as observed by Eirale et al. [5]. However, injury during training was not associated with Ramadan or religion/fasting status. 06 Injury type and location were similar in Ramadan and non-Ramadan periods as observed by Eirale et al. [5]. he most common location of injury was thigh, followed by knee, and ankle in both periods. Also, the most common types of injury were muscle rupture and ankle sprain, followed by tendon injury, and contusion in both Ramadan and non-Ramadan periods. Eirale et al. [5] suggested that the similarity between injury characteristics and patterns may have important practical implications for the medical staf, as the same strategies for injury prevention may be applied during both Ramadan and out-Ramadan periods. he injury rates reported during the month of Ramadan in both published studies [4,5], during training and matches, were consistent with data found in Union of European Football Associations {UEFA} [1], English Premier League [27], Swedish Premier League [28], Scottish league [2], and Norwegian league [3]. Nevertheless, the overuse injury rate of the study of Chamari et al. [4] outside the month of Ramadan is lower than what is typically reported in the literature. It has been stressed by the authors that this muscle injury rate concerns pre-season and the start of the season (because Ramadan was located quite soon during the season) and this might explain these lower rates. Indeed, pre-season is characterized by a high prevalence of endurance training and itness training which were performed in a progressive manner by the staf of the studied team. he low frequency of matches at these stages might be the cause of the low overall injury rates of the studied periods [4]. Indeed, it has been well demonstrated that the match injury rates are always much higher than the training injury rates [1]. In this context, Koutedakis and Sharp [29] also showed that the preparation phase of the season is accompanied with fewer injuries than the competition phase. Despite a higher mean overall injury rate during the Ramadan months of the 2 studied seasons [4], i.e. 12.3 injuries/1000-h exposure vs 4.9 for the month’s before-Ramadan and 6.7 for the month’s ater-Ramadan, the diference between non-fasting and fasting players was not signiicant. his result was later conirmed by Eirale et al. [5]. Nevertheless, the rate of overuse injuries during training was signiicantly higher during Ramadan than before- and ater-Ramadan in the fasting players (Table 3). However, these players showed lowered Hooper’s index and perceived stress during and ater the Ramadan than non-fasting players [30]. Moreover, no diference was observed between fasting and non-fasting players for the reported quality of sleep, and quantity of delayed onset muscle soreness and fatigue during, before, and ater Ramadan (Figure 3). + each period consisted of 4 weeks in each year, respectively. a signiicant different from non-fasting players at p<0.05. Figure 3: Comparisons of Hooper Index, (sleep, stress, delayed onset muscle soreness, and fatigue) {means of the 2 studied seasons} [4]. It is also important to note that the study of Chamari et al. [4] reported data of players that trained at night during Ramadan and that the technical staf avoided days including two training sessions but for very few exceptions. Consequently, their conclusions are not adaptable to Fasting players keeping training during the day. In this context, Elite Football teams oten train in the morning (with the possibility of performing double sessions’ days in some one-game per week microcyles), therefore fasting players would have to keep of their food and luid intakes for the periods occurring just ater the training sessions. his has to be considered with caution as the latter intakes are part of the pillars of recovery. More speciically, ending a high load training session at around 11h00 a.m. and having to keeping on fasting for the remaining hours until the sunset (Itar) presents a big challenge for fasting elite athletes, especially for the long daylight days (i.e., summer in the northern hemisphere). In this case, the eventual addition of a second training session in the aternoon is certainly not physiologically optimal and to the best knowledge of the present chapter’ authors, no study has investigated such a training situation. In this context, some recommendations have been made by Kirkendall et al. [31] for advising the technical stafs and athletes to better deal with training during Ramadan. In this regard, further studies on injuries during Ramadan in diferent parts of the world, and through the year calendar are obviously needed. Other speciic situations should also be investigated as some players chose to fast during the week but not the day of the games as many coaches wish to have non fasting players for games (data not published yet). his presents another pattern of speciic fasting with related physiological adaptations and therefore performance and injury pattern. OMICS Group eBooks Despite the diference in Hooper Index and perceived stress observed, Chamari et al. [4] showed that training load, training strain, and training duration were maintained during the 3 periods (pre-, post- and during Ramadan) and between groups for the 2 monitored seasons (Figure 4). Of interest is to mention that the technical stafs of this study [4] had not decrease training load during Ramadan. his has been decided on basis of the key indings of Chaouachi et al. [6] who has suggested that elite athletes who were maintaining their usual training loads, could avoid steep decrements in their physical capacities while undergoing the Ramadan intermittent; However, although there is no study contrasting the suggestions of Chaouachi et al. [6], technical stafs should adapt the training load of their players based on daily observations and fasting conditions and environment. he suggestion of Chaouachi et al. [6] concerned elite Tunisian judo athletes with diferent characteristics of training compared to European top-level soccer teams for example. Indeed, in Tunisia, there is lower frequency of competitions/matches than in European top-class teams with games played each 3-4 days almost continuously for about 10 months (about 25 to 40 games vs. 45-62 games, for elite Tunisian and European teams, respectively). Another concern with Ramadan fasting in Europe comes from the daylight duration. Indeed, in summer for example, fasting players in Europe abstain from food and luids for 1 to 2 hours longer than northern African countries as Tunisia for example. In summer, with the relative heat, this could be a challenge for Muslim fasting players that are part of a European team. Indeed, in such cases, technical stafs of elite athletes have performance’ objectives and hence, do not even think about managing the whole team training pattern/load for some exceptions as fasting players. 07 + each period consisted of 4 weeks respectively in each season. A.U.: arbitrary units Figure 4: Comparisons of weekly training load, strain, and duration {mean of the 2 studied seasons} [4]. Possible Causes of Sport Injuries during Ramadan Consequences of sleep disturbance Regarding the possible relationship between sleep loss and sport injuries, Luke et al. [32] demonstrated in adolescents that fatigue related injuries were associated with sleeping less than 6-h the night before the injury. One study has investigated sleep and injury rates in athletes during Ramadan. Chamari et al. [4] retrospectively analyzed the quality of sleep via the Hooper Index and recorded injury data for two years in Tunisian top-level football players (n=42). Training load remained unchanged throughout the study period but the timing of training was delayed from mid aternoon to 2200-h. Despite no change in perceive sleep quality, the timing of sleep was considerably delayed, with players not going to bed before 0300-h. Non-contact and training-overuse injuries were higher during the month of Ramadan among fasting players [4]. Nevertheless, even if the fasting players were generally satisied with self-reported sleeping quality, it may be that the total sleep duration or time spent in the diferent sleep stages was modiied. In this context, it has been well established that sleep architecture is characterized by a cyclic pattern of sleep stages throughout the night [33,34] and that disturbances during Ramadan can negatively afect alertness and psychomotor skills [35]. In that regard, disturbances to the circadian timing of the sleep-wake cycle – either due to delayed nutritional intake, exercise or both, may present physiological or psychological challenges occurring with circadian mis-alignments, that if not overcome will impact on athletic performance [36] herefore, changes in sleeping pattern (i.e. less sleep at night and more aternoon naps) and nutritional habits (i.e. eating only at night-time) during Ramadan may have altered the players’ physiological status during Ramadan, probably leading to the observed higher over-use injury rate during the fasting month [37-39]. Physiological and hormonal disturbances Besides sleeping schedule disturbances, another probable cause of overuse injuries could be the end-of-Ramadan state of the fasting players. In this regard, Chaouachi et al. [13] have demonstrated that elite athletes continuing to undergo high training loads during Ramadan (at the same levels as before Ramadan) might display high levels of fatigue and are likely to experience a cascade of small ‘’negative’’ biochemical adjustments: changes in hormonal, immunoglobulin, and antioxidant systems, along with an elevated inlammatory proile. hese variations are similar to what is found in tissue traumatic processes as observed in athletes in state of overreaching or even overtraining [13]. Although the reported variations are minimal and of small clinical relevance, they can still signal whole body’ physiological stress [13]. In this context, the overtraining syndrome has been referred as ‘’staleness or chronic fatigue and a mental lassitude along with possible associated injuries in parallel to a signiicant decline in physical performance’’ [40,41]. Overtraining has been shown to afect the musculoskeletal system with increased serum creatine kinase levels and enzymatic markers of muscle tissue injury that signiicantly elevated the day ater high training loads’ training sessions. For now, it is unclear whether the observed over-use injuries observed in the over-trained or over-reached athletes described in the literature could be resulting from excessively high training loads and/or the impaired ability of the athletes to recover from underwent training loads. As training load was similar in fasting and non fasting players in the study of Chamari et al. [4], it is therefore possible that the recovery processes could be altered by Ramadan intermittent fasting. Further studies are needed in this speciic ield. Contradictory with many studies (see for review [6] suggesting that the Ramadan month induces additional stress on the athlete, the perceived mental stress assessed by the Hooper scale during Ramadan in the non-fasting players of the study of Chamari et al. [4] was not diferent from stress measured before and ater Ramadan. Rather, the fasting players reported decreased stress for Ramadan and for the month ater-Ramadan compared to the pre-Ramadan month. he latter authors speculated that the religious beliefs and the well-being of living and practicing a holy month, could have led to a lower perception of stress in the fasting players. he possible habituation process in the fasting players has also to be considered. Indeed, the latter reported that they had fasted and trained at night simultaneously for a mean period of seven years. herefore, the absence of total injury risk diference with respect to the non-fasting players relates to habituated fasting players training at night in non-fasting state (see section 5.4 of present book chapter). Newly fasting players’ data are not available from the study of Chamari et al. [4]. OMICS Group eBooks Psychological alteration and general fatigue 08 Contextual conditions he efect of Ramadan on the incidence of sporting injuries has to be considered with respect to the period of the year and changing climate. Indeed, the study of Chamari et al. [4] was conducted over the 2010 and 2011 years with the months of Ramadan occurring in August/September. For that study, the daily fasting lasted about 15h15min in Tunisia and the temperature was relatively high (see above table 2). Several fasting periods and environmental conditions should be experimented with respect to their efects on elite athletes’ injury rates. It has also to be noted that in the study of Chamari et al. [4] the training sessions occurred during the evenings (22h00, i.e. about 3 hours ater the ‘’itar’’ / breaking of the day’s fast). In this context, the injury rates reported concern therefore ‘’Fasting’’ players that were in a non-fasting state, as they did break the fast about three hours earlier and were thus allowed to drink ad-libitum before and during the training sessions and games. At present, no data is yet available for any injury rate occurring in fasting athletes during training or competition. Recommendations and Conclusion he only two studies in scientiic literature [4,5] on the muscle and general injury rate during the month of Ramadan were conducted in professional football players and show that the many changes in behavioral and social-routines occurring during the Ramadan fasting may potentially afect the injury risk of these athletes. In Muslim-majority countries, non-fasting players may also be afected by changes in eating and sleeping habits and in the scheduling of training and match play. Data of Chamari et al. [4] and Eirale et al. [5], however, show the absence of the efect of the holy month of Ramadan on the general injury rates of fasting and non-fasting elite soccer players where weekly training loads were maintained during Ramadan [4]. However, according to Chamari et al. [4] rates of non-contact injuries and rates of overuse injuries during training were higher during Ramadan than before or ater Ramadan in fasting compared to the nonfasting players. On the other hand, Eirale et al. [5] have found a higher rate of match and total injuries in non-Muslim players during Ramadan and out-Ramadan periods. his diference was maintained for match injuries during the Holy month of Ramadan and the following 2 months ater adjusting the data for age. hese results could be explained by the possible inability of non-Muslim players to manage with changes in the circadian rhythm and sleep pattern imposed by the altered schedule during Ramadan in addition to the issue they face with adapting to the hot and humid climate in Qatar, which may constitute another risk factor for sport injury. herefore, it is recommended that coaches and medical stafs involved in the management of fasting players should monitor and adapt the training load according to the timing of Ramadan on the year’s span (environmental conditions), and the cultural background and competing level of the players. 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Reilly T, Waterhouse J (2007) Altered sleep-wake cycles and food intake: the Ramadan model. Physiol Behav 90: 219-228. 40. Kenttä G, Hassmén P (1998) Overtraining and recovery. A conceptual model. Sports Med 26: 1-16. OMICS Group eBooks 41. Halson SL, Jeukendrup AE (2004) Does overtraining exist? An analysis of overreaching and overtraining research. Sports Med 34: 967-981. 010 Sponsor Advertisement TIF Publications TIF Publications cater to the needs of readers of all ages and educational backgrounds, and provide concise up-to-date information on every aspect of thalassaemia - from prevention to clinical management. TIF’s publications have been translated into numerous languages in order to cover the needs of the medical, scientific, patients and parents communities and the general community. List of Publications - ORDER YOUR BOOKS! N E W ! Ju s t R e le a se d! N E W ! 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