Effect of Intermittent Fasting on Athletes


Effectof Intermittent Fasting on Athletes

Effectof Intermittent Fasting on Athletes

IntermittentFasting (IF) is a current meal-timing schedule. It refers to theprocess of abstaining from any energy intake for periods of 16 to 20hours per day. Consequently, individuals can condense their energyintake into a short period spanning 4 to 8 hours. Fasting refers tothe time during which one eats no food. The fasting periods last for12 hours such as the overnight fasting or it may take a longerduration such as two weeks. Some of the outcomes of IF include weightloss. It also enhances the capacity of the body to generate energyfrom stored fats through decreasing intake of energy and oxygen fromthe muscles. Subsequently,intermittent fasting improves the running performance of athletes.

Thebenefits of intermittent fasting

Pareysonand Marchesi (2009) assert that food is fuel, especially for seriousrunners who need a lot of energy. It may seem counterintuitive tofast before a workout, but some proponents claim it can benefit anathlete’s performance.

Accordingto Collier (2013), athlete participants, especially men who exerciseovernight Intermittent Fasting, experience greater performanceinduced improvement. The performance is due to the improved abilityto use oxygen. Besides, the athletes record higher levels of energyin their muscles. Collier (2013) argues that IF is associated withincreased endurance among cyclists for a four weeks period as opposedto running athletes. Specifically, intermittent fasting increasesthe athlete’s ability to utilize fat by lowering the body’sintake of oxygen and energy from the muscles. Consequently, endurancerunners exercise intermittent running to train the body how to useenergy and oxygen. However, the increased effect may not last formany days.

Accordingto Fogelholm (2008), IF increases the energy levels of the athletedue to the less use of effort during digestion. Consequently, theathletes can direct most of their energy towards exercise. Some ofthe additional benefits of intermittent fasting include improvedmemory and the potential decrease in the risks of certain diseases(Fogelholm, 2008).

Studies,such as Andresen (2009), contend that intermittent fasting is crucialas it can help to regulate the body weight. The studies provide thatIF leads to significant decrease in weight, Body Mass Index (BMI),morning Self Monitoring of Blood Glucose (SMBG). It also helps toreduce overall reduction in waist circumference, C-reactive protein,energy intake, carbohydrate and fat intake (Andresen, 2009).

Proponentsfor increased performance during intermittent fasting

Fogelholm(2008) provides that intermittent fasting is another way of fastingthat is most easily exemplified by the way Muslims fast during theRamadan. According to (Cherif, Roelands, Meeusen, &amp Chamari,2015), the single vertical jump performance, the peak, force and thepeak energy of Judokas remained unaffected when athletes maintainedtheir training load after Ramadan. However, it was observed thatfasting had an effect on the mean power that was emitted by high jumpathletes.

Accordingto Andresen (2009), Tunisian soccer players recorded an improvedperformance after Ramadan compared to that recorded before Ramadan.The improvement occurred whenever the training load was improvedimmediately after Ramadan. Consequently, it is possible to concludethat fasting has a positive impact on the physical performance ofathletes.

Similarly,Cherif et al. (2015) agrees that athletes can sustain their stellarperformance whenever they maintain their energy intake afterexperiencing intermittent fasting. Consequently, Fogelholm (2008)shows that several aspects of athlete’s performance are maintainedafter intermittent fasting.

Theeffect of intermittent fasting on body mass

Accordingto Javad (2010), athletes’ maintained the sports performance duringand after Ramadan. As a result, athletes’ body mass remainedunaffected. Specifically, the performance aspect included the peakrunning distance, the time and the velocity for an athlete associatedwith a 20-meter short run. Besides, athlete shuttle run relatedcharacteristics were also maintained after intermittent fastingsimilar to the period of intermittent fasting (Javad, 2010).

Asfor Karate Athletes, Zarrouka, Hugb, Hammoudac, Rebaid, Tabkad,Doguia and Bouhleld (2013) indicate that the athletes are able tomaintain their body mass and the isometric submaximal kneeextension-contraction time (at 75% contraction till the time whenthey become exhausted) during Ramadan similar to the period ofRamadan.

Collier(2013) provides that whenever body mass and energy intake aremaintained during the period of intermittent fasting, the body massof the athletes remains unchanged. Similarly, whenever the athletesmaintain their energy intake during Ramadan, there is no observablechange in the athlete’s fitness.

Inconclusion, intermittent fasting increases the performance levels ofathletes. Specifically, it increases their endurance by improving thecapacity of the body’s energy usage. Besides, intermittent fastinghas minimal effects on the body mass of the athlete.

Effectsof intermittent fasting on the hydration of the athletes

Accordingto Bigard, Boussif, Chalabi, and Guezennec (1998), intermittentfasting results in increased hematocrit and hemoglobin values.Besides, it causes a reduction amounting to plasma. Similarly, duringRamadan, Aloui (2013) indicates that the athletes experience adecrease in their urine and increase the amount of sodium, potassiumand total solute excretion in their urine. The symptoms depict thatthe employees experience hydration problems during intermittentfasting.

Proponentsfor decreased athlete performance during intermittent fasting.

Accordingto Swilleh (1992), during Ramadan, the body mass of athletes issignificantly reduced. The body weight is attributed to the loss ofwater and a decrease amounting to fat. Consequently, the decline ofwater can lead to impairment in the level of athlete performance.Specifically, the loss of the quantity of water reduces the enduranceof exercise performance of the athletes.

Accordingto Pareyson and Marchesi (2009), the majority of the studiesidentified that majority of the participants tolerated IntermittentFasting. Consequently, there were no severe adverse events. Thestudies on intermittent fasting realized that morning nausea was themost common complaint. The complaint abruptly ceased when medicationtiming was changed.

Cherif,et al., (2015) provides that fasting leave an athlete with littleenergy in their tank. Consequently, the athlete may not be able tosustain energy needs for longer periods. The deficiency in energyfurther reduces the speed of the athlete. It is important for anathlete to have a pre-exercise meal that is composed ofcarbohydrates. The carbohydrates improve the athlete’s endurance.Andresen (2009) provides that eating the best meals before a raceenhances the performance of the marathoner. Short fasts before therun are harmful they result in dizziness, nausea, and weakness.Long-term fasts lead to nutritional deficiencies.

Fogelholm(2008) state that among the disadvantages of intermittent fasting isthe ability to causes the athlete’s body to burn muscle. Burningthe flesh leaves the Athlete weaker in the long run they are unableto handle high energy activities such as hills and speed. Besides,fasting is dangerous for runners that have medical conditions likediabetes

Accordingto Maugan (2003), the resultant dehydration from intermittent fastingreduces the cognitive abilities of the athletes. Besides, the effecton the cognitive ability happens before the physical ability isaffected. Mild dehydration also translates into a reduced rate ofsubjective translation of the alertness of the athletes.

Collier(2013) provides that the decline in an athlete’s performance iscaused by the decrease amounting to water that further results infatigue. It consequently explains the decrease in performance. Aboutjudo athletes, Chaouachi (2009) agrees that during intermittentfasting, there were higher fatigue scores. The athletes experiencefatigue in an attempt to maintain normal training loads and majorityof their physical performance levels. Similarly, during Ramadan,daytime fasting results in fatigue that reduces the athlete’sperformance. Consequently, the athletes recorded higher rating ofperceived exertion scores (RPE) compared to the scores during thecontrol period.

Ramadanrelated fatigue may emanate from disturbances in the sleep ofathletes

Collier,(2013) argues that during Ramadan, fatigue may result fromdisturbances in the cycles of sleeping. Sleep duration may getaltered by a large amount of food eaten by the athletes at night andthe consequent religious events that happen in the night.

Accordingto Chaouachi (2009), the lack of sufficient sleep during the Ramadanperiod may explain the effects of reduced physical performance duringRamadan. Specifically, the impact of sleep on physical performance isevident during the afternoon. According to HajSalem (2013) a 30 –swin rate test proved that whenever athletes are deprived of theirsleep, they result in reduced muscle power output. In contrast,short-term performance sports such as the handgrip test are notsignificantly affected by sleep loss. According to Souissi (2013),the athlete’s performance during a contraction and handgrip testwere only affected by partial sleep loss during the afternoon hoursand not in the morning hours of the day after sleep deprivation.

Inconclusion, Ramadan is similar to intermittent fasting. DuringRamadan, the athletes are exposed to long periods of lack of sleep.The deprivation of sleep among athletes contributes to fatigue andconsequently reduces their performance (Fogelholm, 2008).


Fromthe preceding discussion, it is possible to conclude thatintermittent fasting has an effect on the performance of athletes. Specifically, it increases the performance of athletes by configuringthe bodies to function in a deficient nutrient situation.Consequently, intermittent fasting increases the endurance capabilityof the athletes.

Theprimary cause of reduced performance for Ramadan athletes is due toprolonged deprivation of sleep. Therefore, the athletes are advisedto take naps in between the course of their exercise to reduce theirfatigue levels. The athletes are also encouraged to ensure that theyhave enough sleep. Other effects of intermittent fasting include thereduction in hydration of the athletes. Hydration causes the fatigueamong the athletes that consequently lead to the decline inperformance. It is advisable for the athletes to increase their fluidintakes to balance off the dehydration due to intermittent fasting.


Theabove discussion has brought to the conclusion several facts. First,intermittent fasting is a healthy meal timing strategy for athletics.Specifically, it increases the athlete’s performance by enhancingthe endurance of their bodies to work with little energy. DuringRamadan, the performance of athletes is curtailed by the long hoursthe athletes are deprived off from sleep. Consequently, the fatiguelevels of the athletes increase and curtails their performance.


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