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This study aimed to assess the effects of the lunar cycle on diurnal variation of biological, i.e, hormonal, biochemical, and hematological, profiles of diurnally active healthy men. Blood samples of 20 males were collected on four occasions [full moon (FM) and new moon (NM), in the morning (06:00–07:00 h) and evening (19:00–20:00 h)]. The results showed that melatonin and testosterone levels and neutrophils count were lower during the FM as compared to the NM in the morning (p <.001; d = 4.13, p <.001; d = 3.84, p <.01; d = 0.77, respectively) and evening (p <.001; d = 6.36, p <.001; d = 4.03, p <.05; d = 1.07, respectively) samples. However, cortisol level was higher during the FM compared to the NM, in the morning (p <.001; d = 0.74) and evening (p <.001; d = 3.54). Hemoglobinemia was higher only in the evening during the FM compared to the evening of the NM (p <.01; d = 1.22). In summary, this study confirmed that lunar cycle can affect human biological parameters independently of time of day. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the effect of the lunar cycle and time of day on short-term maximal performance, wellness and mood state. Twenty healthy active men performed a running anaerobic sprint test (RAST) at four sessions (full moon (FM) and new moon (NM) in the morning and in the evening). Before each testing session, participants completed a rating scale of mood states (POMS) and a psychometric rating scale of perceived wellness (Hooper's questionnaire). Rating of perceived exertion (RPE) was collected just after the RAST. A higher rating of sleep was observed in FM compared to NM upon the morning and the evening (FM morning vs. NM morning, p <.01; d = 1.38) and (FM evening vs. NM evening, p <.001; d = 2.62). POMS subscales data revealed no significant lunar cycle effect. Peak power (PP), average power (AP) and minimal power (MP) were greater in the evening following NM compared to FM (NM evening vs. FM evening, p<.01, <0.01, <0.05; d = 0.77, = 0.78, = 0.68, respectively). Likewise, RAST performance was greater in the evening compared to the morning for both lunar cycle phases (FM evening vs. FM morning, p<.001, <0.01, <0.01; d = 1.08, = 1, = 0.85) and (NM evening vs. NM morning, p<.001, <0.01, <0.01; d= 1.08, = 1, = 0.85), respectively, for PP, AP, and MP. RPE was higher in the FM evening compared to the NM evening and in the FM morning compared to the NM morning (p <.001, <0.001; d = 1.38, = 2.18, respectively). These results suggest that the lunar cycle and time of day might affect short-term maximal performance with better performance on NM evening associated with a greater perception of sleep quality compared to FM. Abbreviations: AP: Average power; FM: full moon; MP: Minimal power; NM: new moon; RAST: Running anaerobic sprint test; RPE: Rating of perceived exertion; POMS: Rating scale of mood states; PP: Peak power [ABSTRACT FROM AUTHOR]

The present study aimed to explore the effects of a single 10-mg dose of melatonin (MEL) administration after exhaustive late-evening exercise on sleep quality and quantity, and short-term physical and cognitive performances in healthy teenagers. Ten male adolescent athletes (mean ± SD, age = 15.4 ± 0.3 years, body-mass = 60.68 ± 5.7 kg, height = 167.9 ± 6.9 cm and BMI = 21.21 ± 2.5) performed two test sessions separated by at least one week. During each session, participants completed the Yo-Yo intermittent-recovery-test level-1 (YYIRT-1) at ~20:00 h. Then, sleep polysomnography was recorded from 22:15 min to 07:00 h, after a double blind randomized order administration of a single 10-mg tablet of MEL (MEL-10 mg) or Placebo (PLA). The following morning, Hooper wellness index was administered and the participants performed the Choice Reaction Time (CRT) test, the Zazzo test and some short-term physical exercises (YYIRT-1, vertical and horizontal Jumps (VJ; HJ), Hand grip strength (HG), and five-jump test (5-JT)). Evening total distance covered in the YYIRT-1 did not change during the two conditions (p > 0.05). Total sleep time (Δ = 24.55 mn; p < 0.001), sleep efficiency (Δ = 4.47%; p < 0.001), stage-3 sleep (N3 sleep) (Δ = 1.73%; p < 0.05) and rapid-eye-movement sleep (Δ = 2.15%; p < 0.001) were significantly higher with MEL in comparison with PLA. Moreover, sleep-onset-latency (Δ = -8.45mn; p < 0.001), total time of nocturnal awakenings after sleep-onset (NA) (Δ = -11 mn; p < 0.001), stage-1 sleep (N1 sleep) (Δ = -1.7%; p < 0.001) and stage-2 sleep (N2 sleep) (Δ = −1.9%; p < 0.05) durations were lower with MEL. The Hooper index showed a better subjective sleep quality, a decrease of the subjective perception of fatigue and a reduced level of muscle soreness with MEL. Moreover, MEL improved speed and performance but not inaccuracy during the Zazzo test. CRT was faster with MEL. Morning YYIRT-1 (Δ = 82 m; p < 0.001) and 5-JT (Δ = 0.08 m; p < 0.05) performances were significantly higher with MEL in comparison with PLA. In contrast, HG, VJ and HJ performances did not change during the two conditions (p > 0.05). The administration of a single dose of MEL-10 mg after strenuous late-evening exercise improved sleep quality and quantity, selective attention, subjective assessment of the general wellness state, and some short-term physical performances the following morning in healthy teenagers. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of an Olympic-Weightlifting-session followed by 48-h recovery period on the oxidative and antioxidant parameters’ diurnal variation. Nine weightlifters (21 ± 0.5 years) performed, in randomized order, three Olympic-Weightlifting-sessions at 08 h:00, 14 h:00 and 18 h:00. Blood samples were collected: at rest and 3 min and 48 h after each session. C-reactive protein (CRP), rate of lipid peroxidation and antioxidant activities were assessed. At rest, analysis of variance showed a significant time of day (TOD) effect (p < 0.05) for uric acid, catalase and glutathione peroxidase with higher values at 14 h:00 and 18 h:00 compared with 08 h:00. However, no significant TOD effect for malondialdehyde, total bilirubin and CRP was observed. Given the profound changes (p < 0.001) in the post-training session values, these diurnal variations have been altered immediately and even 48 h after the training sessions. Despite the significant decreases in the post-training values after the 48-h recovery period (p < 0.05), levels of lipid peroxidation and enzymatic defense remained elevated (p < 0.05) 48 h after the morning training session. However, after the afternoon and evening sessions, the same period was sufficient to return values to the baseline levels. In conclusion, the morning session seems to generate the most important acute and delayed lipid peroxidation responses. Therefore, weightlifting coaches should avoid scheduling their training sessions in the morning-hours. [ABSTRACT FROM AUTHOR]

The aim of this study was (i) to evaluate whether homocysteine (Hcy), total antioxidant status (TAS), and biological markers of muscle injury would be affected by time of day (TOD) in football players and (ii) to establish a relationship between diurnal variation of these biomarkers and the daytime rhythm of power and muscle fatigue during repeated sprint ability (RSA) exercise. In counterbalanced order, 12 football (soccer) players performed an RSA test (5 × [6 s of maximal cycling sprint ++ 24 s of rest]) on two different occasions: 07:00-08:30 h and 17:00-18:30 h. Fasting blood samples were collected from a forearm vein before and 3-5 min after each RSA test. Core temperature, rating of perceived exertion, and performances (i.e., Sprint 1, Sprint 2, and power decrease) during the RSA test were significantly higher at 17:00 than 07:00 h ( p < .001, p < .05, and p < .05, respectively). The results also showed significant diurnal variation of resting Hcy levels and all biological markers of muscle injury with acrophases (peak times) observed at 17:00 h. These fluctuations persisted after the RSA test. However, biomarkers of antioxidant status' resting levels (i.e., total antioxidant status, uric acid, and total bilirubin) were higher in the morning. This TOD effect was suppressed after exercise for TAS and uric acid. In conclusion, the present study confirms diurnal variation of Hcy, selected biological markers of cellular damage, and antioxidant status in young football players. Also, the higher performances and muscle fatigue showed in the evening during RSA exercise might be due to higher levels of biological markers of muscle injury and lower antioxidant status at this TOD. (Author correspondence: ) [ABSTRACT FROM AUTHOR]