BIOLOGICAL CHALLENGES OF RAMADAN
The recent paper of Eirale et al1 reminds us that a growing proportion of participants in both national and international athletic competitions are Muslims, required by their faith to abstain from food and drink from sunrise to sunset each year throughout the 29 days of Ramadan. Several articles have examined the effects of such intermittent fasting on sleep patterns,2 circadian rhythms,3,4 psychomotor performance,5 body physiology and biochemistry,6–10 training response, and performance11–13 of athletes. Reported changes in most parameters have commonly been small, although there are important limitations to the available data. Often, there has been no matched control group, and the level of competition of the subjects has been poorly defined. It has been unclear how sleep disturbances were managed, whether diet was adjusted, whether training was relaxed during Ramadan, and whether any control group faced similar changes in sleep patterns, meal times, and their times of training. Evaluated parameters have sometimes been measured early in the morning, or in the evening after breaking the fast, when any effects of a daytime fast would be minimal, and little is known about the impact of intermittent Ramadan fasting on what seems the most vulnerable group, participants in endurance and ultra-endurance competition.
Endurance athletes and participants in team sports who engage in Ramadan fasting seem likely to sustain a greater decrease in blood glucose levels and body fluids than non-Muslims who can ingest carbohydrate containing beverages as desired during an event. With careful management, those who are fasting can make good much of the food and fluid deficit at night, but there is often a progressive depletion of body fat stores over the course of Ramadan. Moreover, the hours available for sleeping are substantially reduced and circadian rhythms may be displaced by the Ramadan requirements to perform additional “good deeds,” to attend prayers each evening, and to share in communal nighttime meals.
EFFECTS ON CEREBRAL FUNCTION
Loss of sleep, disturbance of circadian rhythms, a reduced blood glucose, and dehydration might all have adverse effects on vigilance, reaction times, and mood state. Studies in sedentary individuals have certainly shown such trends.14–16
Given the much higher rates of both energy expenditure and fluid loss in athletes, the impact of Ramadan on cerebral function is likely to be greater than that seen in the general population, particularly in the hours immediately before sunset. One report noted some deterioration in the recognition and reaction times of resistance athletes during the first week of Ramadan,17 but measurements were made at noontime rather than in the late afternoon, when the effects of fasting would have been much more severe. Afternoon measurements on martial arts competitors also demonstrated a deterioration of verbal learning and memory during Ramadan; this finding was associated with a small decrease of serum glucose (from 5.4 to 4.6 mmol/L), although subjects were not clinically hypoglycemic.18
COGNITIVE DISTURBANCES AND RISK OF INJURY
There has been little evaluation of the possible influence of cognitive disturbances on the risk of injuries, either on the road or on the sports field.
Newspaper reports have frequently suggested an increase of road traffic accidents during Ramadan, but empirical evidence is less convincing. In the United Arab Emirates, a 1-year study of 1197 hospital-treated injuries found a “slightly higher” risk during Ramadan,19 and in Saudi Arabia, the “maximum number” of traffic victims was seen during Ramadan.20 In Britain, the proportion of Muslims attending a hospital emergency clinic increased from 3.6% to 5.1% for all patients during Ramadan, with the number of injuries showing a similar (but nonsignificant) trend.21 In contrast, the number of traffic injuries decreased during Ramadan in Morocco22 and Jordan.23 Incidents were not reported per vehicle-kilometer in any of these studies, and 1 possible source of discordant results could be altered travel patterns during Ramadan. Other important yet uncontrolled variables that are associated with Ramadan in some Muslim countries are the banning of alcohol sales22 and a shortening of working hours throughout the month. Some authors have noted an increased irritability during Ramadan, as might be anticipated with a low blood sugar level,24,25 and this could affect the risk of motor vehicle injuries. However, 1 article argued that despite this risk, the spiritual atmosphere of the season encouraged motorists to drive in a more courteous fashion.23
Athletes themselves have suggested that sports injury rates are increased during Ramadan. Thus, Nadir Belhadj, an Algerian professional soccer player, told the first consensus conference on Ramadan and Football (Qatar, 2011), “I feel there are for sure more injuries during fasting.”26 There have been 2 empirical studies of soccer players.1,27 A group of 42 men from top Tunisian teams were followed over 2 years, with the incidence of injuries being compared between habituated fasters and nonfasters before, during, and after Ramadan.27 Neither group was able to go to bed until 3.00 hours during Ramadan. Injuries were defined somewhat subjectively as physical complaints that caused a player to miss all or part of a training session or match, and rates were expressed per 1000 hours of soccer exposure. Because the study was conducted in a predominantly Muslim country, training sessions were delayed until 22.00 hours during Ramadan, almost 3 hours after the players had broken their fast, so no short-term adverse effects of glucose or fluid depletion would have been expected. The training load also remained constant, and somewhat surprisingly the fasters reported a lower score than nonfasters on Hooper's index (a measure that reflects fatigue, stress, muscle soreness, and sleep disorders). The overall injury rate remained similar for fasters and nonfasters during Ramadan, but there was a substantial increase in overuse and noncontact injuries among the fasters, suggesting an effect from altered diet and associated inflammatory and immune changes rather than from a disturbance of vigilance or mood state.28
Eirale et al1 made a similar study of professional first division soccer players from Qatar. The same definition of injury was adopted, and as in the Tunisian study, all of the training sessions and matches during Ramadan were conducted in the late evening, after breaking the fast. However, the Qatar study was able to collect less information on changes of sleep, diet, and training than in the Tunisian investigation. Ramadan had no effect on the risk of either contact or noncontact injury in the Qatari players, but the overall injury rate during and for 2 months after Ramadan was higher in non-Muslims than in Muslims. This finding illustrates the problem of finding a well-matched control group. The non-Muslims in this study were some 3 years older than the Muslims, and most were foreign immigrants who had greater difficulty than local players in coping with the heat and humidity of the Gulf region, plus the changes of feeding and sleep schedules imposed by a community-wide celebration of Ramadan.
It is encouraging that the observance of Ramadan does not seem to increase the risk of nighttime soccer injuries. However, neither of the currently available studies provides a complete answer to the risk of sports injuries during Ramadan. Many western countries are unlikely to postpone soccer matches, other types of athletic competition, or even training sessions until 3 hours after sunset, to allow Muslim athletes opportunity to replenish their food and fluid reserves. Further information is thus needed on the risks of Ramadan observance for Muslims who are living in a minority situation, where they may be obliged either to train or to compete at an hour when their carbohydrate and fluid reserves have reached their nadir.
There is also a need to resolve the present discordant findings on changes in the incidence of noncontact injuries. If this risk of such injuries is indeed increased during Ramadan, we need to know why and how this problem can be minimized. This will require careful recording of not only the quantity and composition of dietary intake but also the timing of meals during intermittent fasting. Elucidation may be helped by documentation of inflammation and the immune responses, together with objective measurements of the severity and duration of injury, to eliminate any suspicion that hunger and thirst have modified the reporting of symptoms of injury.
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