Nocturnal Melatonin Ingestion Improves Soccer Players' Short-Term Maximal Performances on the Following Day.

Purpose: Exogenous melatonin has been proven to have beneficial effects on sleep. A good sleep quality promotes recovery and improves physical performance. In this sense, the present study aimed to explore the potential effect of nocturnal melatonin ingestion on psycho-cognitive and short-term maximal performances, in the following morning. Method: Twelve professional soccer players (22.9 ± 1.3 years, 1.80 ± 0.05 m, and 72.0 ± 8.8 kg) volunteered to perform two separate testing sessions after either nocturnal melatonin or placebo ingestion. The next morning, participants performed the following psycho-cognitive and physical tests: Hooper's index, reaction time, vigilance, handgrip strength (HG), squat jump (SJ), modified agility T-test (MAT) and Wingate anaerobic test (WanT). Rating of perceived exertion (RPE) and blood lactate [La] were recorded, respectively, immediately and 3 min after the WanT. Blood glucose [GL] was measured before and 3 min after WanT. Results: Compared with placebo, melatonin improved subjective sleep quality, short-term maximal performances (HG and SJ), reaction-time, as well as peak and mean WanT powers and decreased fatigue index and RPE scores. However, [La] and [GL] were not affected by melatonin ingestion. Conclusion: Nocturnal melatonin intake before sleep has beneficial effects on cognitive and physical performances the following day.

Melatonin Ingestion Prevents Liver Damage and Improves Biomarkers of Renal Function Following a Maximal Exercise.

Background: While the promotion of the beneficial effects of melatonin (MEL) ingestion on the modulation of oxidative stress is widespread, less attention is given to the biological influence that it could exert on the results of hematology and clinical chemistry parameters. This study was undertaken to assess the effects of acute MEL ingestion on these parameters during a maximal running exercise. Methods: In double blind randomized design, 12 professional soccer players [age: 17.54 ± 0.78 yrs, body mass: 70.31 ± 3.86 kg, body height: 1.8 ± 0.08 m; maximal aerobic speed (MAS): 16.85 ± 0.63 km/h; mean ± standard deviation], all males, performed a diurnal (17:00 h ± 30 h) running exercise test (RET) at 100% of their MAS following either MEL or placebo ingestion. Blood samples were obtained at rest and following the RET. Results: Compared to placebo, MEL intake decreased post-exercise biomarkers of liver damage (aspartate aminotransferase, p<0.001; alanine aminotransferase, p<0.001; gamma-glutamyltransferase; p<0.05) and improved post-exercise renal function markers (i.e., creatinine, p<0.001). However, lipid profile, glucose, lactate and leukocyte were not affected by MEL ingestion. Regarding the time to exhaustion, no difference was found between MEL (362.46 ± 42.06 s) and PLA (374.54 ± 57.97 s) conditions. Conclusion: The results of this investigation clearly attest that MEL ingestion before a maximal running exercise might protect athletes from liver damage and perturbation in renal function biomarkers. However, this study comprises an acute MEL supplementation and no assessment on chronic effects or circadian rhythm the day before was done.

Melatonin supplementation alleviates cellular damage and physical performance decline induced by an intensive training period in professional soccer players.

Melatonin has been proved to have positive effects on cellular damage and metabolic regulation. The aim of the study was to determine the effect of melatonin supplementation during an intensive training period on physical performance decline, oxidative stress and cellular damage state. The investigation was conducted on 20 soccer players who participated in an exhaustive six-day training schedule associated with daily 5 mg oral melatonin or placebo ingestion. Resting blood samples and physical performance were measured before and after the training period. The mixed 2-way ANOVA (group x training camp) showed that compared to placebo, melatonin intake prevented an increase in advanced oxidation protein products (p>0.05) and increased the antioxidant enzyme activity (i.e., superoxide dismutase; p<0.001). In addition, melatonin prevented an increase of biomarkers of renal function (e.g., creatinine; p>0.05) and biomarkers of muscle (e.g., creatine kinase; p>0.05) and liver (e.g., gamma-glutamyltransferase; p>0.05) damage. Furthermore, melatonin alleviated the deterioration in physical performance (countermovement jump, five-jump test and 20-m sprint; p>0.05). In conclusion, the obtained data showed increased oxidative stress and renal, muscle and liver damage in professional soccer players during an exhaustive training schedule. Melatonin intake during the training period exerts beneficial effects on physical performance and protects tissues against the deleterious effects of reactive oxygen species and cellular damage.

Effects of melatonin ingestion on physical performance and biochemical responses following exhaustive running exercise in soccer players.

Antioxidant supplementation has become a common practice among athletes to boost sport achievement. Likewise, melatonin (MEL) has been ingested as an ergogenic aid to improve physical performance. To date, no study has checked whether the multiple beneficial effects of MEL have an outcome during a maximum running exercise until exhaustion. Therefore, the present study aimed to evaluate the effect of MEL ingestion on physical performance and biochemical responses (i.e., oxidative stress) during exhaustive exercise. In a double blind randomized study, thirteen professional soccer players [age: 17.5 ± 0.8 years, body mass: 70.3 ± 3.9 kg, body height: 1.80 ± 0.08 m; maximal aerobic speed (MAS): 16.85 ± 0.63 km/h; mean ± standard deviation], members of a first league squad, performed a running exercise until exhaustion at 100% of MAS, after either MEL or placebo ingestion. Physical performance was assessed, and blood samples were obtained at rest and following the exercise. Compared to placebo, MEL intake prevented the increase in oxidative stress markers (i.e., malondialdehyde), alleviated the alteration of antioxidant status (i.e., glutathione peroxidase, uric acid and total bilirubin) and decreased post-exercise biomarkers of muscle damage (i.e., creatine kinase and lactate dehydrogenase) (p < 0.05). However, physical performance was not affected by MEL ingestion (p > 0.05). In conclusion, acute MEL intake before a maximal running exercise protected athletes from oxidative stress and cellular damage but without an effect on physical performance.

Effect of Ramadan intermittent fasting on cognitive, physical and biochemical responses to strenuous short-term exercises in elite young female handball players.

The present study aimed to assess the effect of Ramadan intermittent fasting (RF) on cognitive and physical performance and biochemical responses to specific exercises in elite young female handball players. Twelve athletes participated in three experimental sessions: one week before Ramadan (BR), during the first week of Ramadan (FWR) and during the last week of Ramadan (LWR). The present crossover study was carried out in Tunisia during the 2013 Ramadan month lasting from 9 July to 7 august. During each session, a battery of tests was performed as follow: Hooper index, vigilance test (VT), Epworth sleepiness scale (ESS), five jump test (5-JT), modified agility T-test (MAT), maximal standing ball-throw velocity test (MSBVT) and Running-based Anaerobic Sprint (RAST) Test. Rating of perceived exertion (RPE) was recorded immediately after the RAST. Blood samples were collected before and after exercises during each session. The results showed that ESS scores were higher during LWR than BR (p < 0.05). Moreover, MSBVT time decreased (p < 0.05) during LWR, therefore performance enhanced. The power of three final sprints from the RAST decreased significantly only during LWR compared to BR (p < 0.05). RAST fatigue index and RPE scores were higher during LWR more than BR (p < 0.05). The results showed also that hematological measures (i.e., red blood cells, hemoglobin and hematocrit), plasma osmolarity and energetic markers were unaffected by RF. Biomarkers of muscle damage were higher after the RAST only during LWR compared to BR (p < 0.01 for all). In conclusion, RF increased ESS and decreased RAST performances associated with higher muscle damage and fatigue, especially at LWR. These previous alterations could be attributed to disturbances of sleep and circadian rhythms rather than nutritional deficiency or dehydratation.

Effect of nocturnal melatonin intake on cellular damage and recovery from repeated sprint performance during an intensive training schedule.

An optimal recovery between training sessions is of similar if not greater importance as the training content and program of the training, itself. One of the most used strategies for improving recovery is the ingestion of supplements. The present study aimed to evaluate the effect of 5 mg oral melatonin supplementation on the recovery from repeated sprint (RSA) of performance and biochemical responses (i.e. oxidative stress, leukocytosis cellular damage) after an intensive training camp (TC). Twenty soccer players performed an RSA test before and after an intensive six-day TC associated with nocturnal melatonin (n = 10) or placebo (n = 10) ingestion. Resting and post-RSA test blood samples were obtained before and after the TC. Compared to placebo, melatonin intake decreased resting oxidative stress markers (i.e, advanced oxidation protein products), leukocytosis (i.e. white blood cells (WBC), neutrophils (NE)) and biomarkers of cellular damage (i.e. creatine kinase (CK)). It also lowered post-exercise leukocytosis (i.e. WBC, NE, lymphocytes (LY), monocytes (MO)) and biomarkers of cellular damage (i.e. CK, aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT)) and raised the activity of the main antioxidant enzymes (i.e. glutathione peroxidase (GPx), glutathione reductase (GR)). In addition, compared to placebo, melatonin reduced the deterioration of the best and total time during the RSA test after the TC. In conclusion, nocturnal melatonin supplementation during an intensive TC alleviated oxidative stress, leukocytosis and cellular damage and improved recovery of RSA performance in soccer players.

Melatonin ingestion after exhaustive late-evening exercise attenuate muscle damage, oxidative stress, and inflammation during intense short term effort in the following day in teenage athletes.

The present study aimed to investigate whether nocturnal melatonin (MEL) ingestion has beneficial effects against exercise-induced oxidative stress and muscle damage in young athletes. Fourteen healthy-trained teenagers performed two-test sessions separated by at least, 1 week. During each session, participants completed the Running-Based Anaerobic Sprint Test (RAST) at 20:00 h. Then, they ingested a single 10-mg tablet of MEL or Placebo (PLA) in a double-blind randomized order at 22:00 h. The following morning (i.e., 07:30 h), participants performed the same test as the previous night. Blood samples were taken before and after exercise. MEL intake increased the peak power (Ppeak) (p < .01), mean power (Pmean) (p < .001) and decreased the total time (TT) (p < .001) and the fatigue index (FI) (p < .05). Furthermore, MEL ingestion attenuated the hematologic parameters before and after exercise (White Blood Cells (WBC: p < .001 and p < .001, respectively); Neutrophiles (NE: p < .001 and p < .001, respectively); Lymphocytes (LY: p < .001 and p < .001, respectively)) and the ultra-sensitive C-reactive protein (us-CRP: p < .001 and p < .001; respectively) compared to PLA. Also, MEL reduced muscle and hepatic damage enzymes before and after exercise (creatine kinase (CK: p < .001 and p < .001; respectively), lactate dehydrogenase (LDH: p < .05 and p < .01; respectively), aspartate aminotransferase (ASAT: p < .01 and p < .001; respectively)), Malondialdehyde (MDA: p < .001 and p < .001; respectively) and Homocysteine (Hcy: p < .001 and p < .001; respectively)) from placebo. Plasma lactate [La] and glucose (GL) remained unchangeable during the two conditions. In summary, acute MEL ingestion after strenuous late-evening exercise attenuated transient leucocytosis and protected against lipid peroxidation and muscle damage induced by strenuous exercise the following morning in healthy male teenage athletes.

Effects of Ramadan Fasting on Recovery Following a Simulated Soccer Match in Professional Soccer Players: A Pilot Study.

Objectives: Assessing the effects of Ramadan fasting on recovery following a soccer match simulation. Methods: Eight elite soccer players (age: 21.0 ± 0.4 years) performed a modified Loughborough Intermittent Shuttle Test protocol (LISTmod) on two occasions: 1 week before (BR) and during the fourth week of Ramadan (End-R). At BR and End-R, soccer players performed squat jump, countermovement jump, maximal voluntary contraction, and 20 m sprint, and creatine kinase, uric acid, and subjective ratings (feelings scale, quality of sleep, fatigue, muscle soreness and stress) were assessed at baseline and 0, 24, 48, and 72 h following LISTmod. Results: Following LISTmod, performance in squat jump (48 and 72 h) (p < 0.05), countermovement jump (48 and 72 h), maximal voluntary contraction (0, 24, 48, and 72 h), and 20 m sprint (0 and 48 h) decreased significantly on both occasions. Decreases were higher at End-R than BR. Creatine kinase levels increased significantly at 24 and 48 h at BR and End-R (p < 0.05). Uric acid increased at 0 and 24 h only on BR. Muscle soreness increased throughout the recovery period at both occasions, with a higher level at End-R. Stress rating increased only at 0 h on End-R, while fatigue rating increased at 24 h at BR and at 0, 24, and 48 h at End-R. Conclusion: Perturbations in physical performance and subjective ratings parameters were higher at the end of Ramadan. However, the results of this study showed that Ramadan fasting did not adversely affect the recovery following soccer match simulation in professional soccer players.

Faster physical performance recovery with cold water immersion is not related to lower muscle damage level in professional soccer players.

The aim of the present study was to assess the effects of cold water immersion (CWI) after an intermittent test on the recovery kinetic of physical performance, muscle damage and perceived muscle soreness in professionals soccer players. In a randomized design, eight soccer players completed the Loughborough Intermittent Shuttle Test followed by 10 min of either CWI (10C°) or thermoneutral water immersion (TWI) (28C°). Physical performance (Squat jump: SJ, countermovement jump: CMJ, maximal voluntary contraction: MVC, and 20 m sprint: SP), muscle damage parameter (creatine kinase: CK) and perceived muscle soreness were assessed at baseline, 0 h, 24 h, 48 h and 72 h after the intermittent test. After the test, a decrease was observed in SJ and in CMJ at 0 h, 24 h, 48 h and 72 h with TWI (p < 0.05) and only at 0 h for SJ with CWI (p < 0.05). SP decreased at 24 h and 48 h after the test with TWI (p < 0.05) and only at 24 h with CWI (p < 0.05). MVC, CK activity and perceived muscle soreness increased in both condition after the test and returned to baseline levels 72 h after the test with TWI (p < 0.05) and at 48 h with CWI (p < 0.05). For the correlation between physical performance and muscle damage parameters in CWI session, the statistical analysis didn't reveal any significant link between CK and SJ, CMJ, MVC or SP values (p > 0.05). The results suggest that CWI immediately after an intermittent test reduces muscle damage and perceived muscle soreness, and accelerate recovery of physical performance in professional soccer players. However, the faster recovery of physical performance seems not be related to the lower level of muscle damage induced by CWI.