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.

Effects of intradialytic exercise in combination with melatonin supplementation on functional capacity, postural balance, and quality of life in hemodialysis patients.

INTRODUCTION: We evaluated the effect of intradialytic concurrent (resistance-endurance) training combined with melatonin (MEL) supplementation on functional capacity, muscle strength, postural balance, and quality of life (QoL) in hemodialysis (HD) patients. METHODS: Thirty-three HD patients were randomized into three groups: Exercise (EX)-MEL (n = 11); EX-Placebo (PLA) (n = 11) and Control (C)-PLA (n = 11). Participants included in the EX-MEL and EX-PLA groups were submitted to concurrent training for 12 weeks. RESULTS: EX-MEL and EX-PLA improved functional capacity, muscle strength, QoL, and postural balance parameters in eyes open and eyes closed conditions. Parameters of postural balance in the dual task condition were improved only in EX-MEL. EX-MEL induced better results in some domains of QoL compared with EX-PLA. CONCLUSION: Intradialytic concurrent training induced beneficial effects on physical function, muscle strength, postural balance, and QoL in HD patients. MEL supplementation combined with intradialytic exercise lead to better improvements in postural balance and QoL.

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 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.

Automated high-throughput heartbeat quantification in medaka and zebrafish embryos under physiological conditions.

Accurate quantification of heartbeats in fish models is an important readout to study cardiovascular biology, disease states and pharmacology. However, dependence on anaesthesia, laborious sample orientation or requirement for fluorescent reporters have hampered the use of high-throughput heartbeat analysis. To overcome these limitations, we established an efficient screening assay employing automated label-free heart rate determination of randomly oriented, non-anesthetized medaka (Oryzias latipes) and zebrafish (Danio rerio) embryos in microtiter plates. Automatically acquired bright-field data feeds into an easy-to-use HeartBeat software with graphical user interface for automated quantification of heart rate and rhythm. Sensitivity of the assay was demonstrated by profiling heart rates during entire embryonic development. Our analysis revealed rapid adaption of heart rates to temperature changes, which has implications for standardization of experimental layout. The assay allows scoring of multiple embryos per well enabling a throughput of >500 embryos per 96-well plate. In a proof of principle screen for compound testing, we captured concentration-dependent effects of nifedipine and terfenadine over time. Our novel assay permits large-scale applications ranging from phenotypic screening, interrogation of gene functions to cardiovascular drug development.

Effects of Pomegranate Juice Supplementation on Oxidative Stress Biomarkers Following Weightlifting Exercise.

The aim of this study was to test the hypothesis that pomegranate juice supplementation would blunt acute and delayed oxidative stress responses after a weightlifting training session. Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-Weightlifting sessions after ingesting either the placebo or pomegranate juice supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. Compared to the placebo condition, pomegranate juice supplementation attenuated the increase in malondialdehyde (-12.5%; p < 0.01) and enhanced the enzymatic (+8.6% for catalase and +6.8% for glutathione peroxidase; p < 0.05) and non-enzymatic (+12.6% for uric acid and +5.7% for total bilirubin; p < 0.01) antioxidant responses shortly (3 min) after completion of the training session. Additionally, during the 48 h recovery period, pomegranate juice supplementation accelerated (p < 0.05) the recovery kinetics of the malondialdehyde (5.6%) and the enzymatic antioxidant defenses compared to the placebo condition (9 to 10%). In conclusion, supplementation with pomegranate juice has the potential to attenuate oxidative stress by enhancing antioxidant responses assessed acutely and up to 48 h following an intensive weightlifting training session. Therefore, elite weightlifters might benefit from blunted oxidative stress responses following intensive weightlifting sessions, which could have implications for recovery between training sessions.

Pomegranate Supplementation Accelerates Recovery of Muscle Damage and Soreness and Inflammatory Markers after a Weightlifting Training Session.

PURPOSE: The aim of this study was to investigate the effect of natural Pomegranate juice supplementation on performance and acute and delayed responses of muscle soreness and biomarkers of muscle damage after a weightlifting training session. METHODS: Nine elite weightlifters (21±0.5 years) performed two Olympic-Weightlifting-sessions after either placebo (PLA) or natural pomegranate juice (POMj) supplementations. Heart rate, blood pressure and blood samples (hematological parameters, muscle damage and C-reactive protein (CRP)) were collected at rest, 3min and 48h after each session. Weightlifting performance, RPE, and DOMS were also assessed after each training session. RESULTS: T-test showed higher performance (+8.30%) and lower RPE values (-4.37%) using POMj supplementation (p<0.05) in comparison with PLA. For the DOMS values, a significant improvement (13.4%) was shown only for the knee extensors (p<0.01) using the POMj. Compared to PLA condition, POMj attenuated the acute (i.e., 3min) increase of systolic blood pressure (SBP), HR, CK and LDH (p<0.05; -4.46%, -1.81%, -8.75%, -1.64%, respectively) and blunted the significant increase of ASAT, PAL and CRP (p>0.05). Additionally, during the 48h following the training session, POMj improved the recovery kinetic of SBP (p<0.01, 7.97%), CK (p<0.001, 11.34%), LDH (p<0.05, 7.30%) and ASAT (p<0.05, 6.77%). Indeed, the present study showed that 48h of recovery associated to natural POMj supplementation was sufficient to reach the resting values of the selected muscle damage markers after intensive training session. CONCLUSION: Natural POMj seems to ameliorate the capacity to adhere to an intensive training program. Therefore, elite weightlifters are advised to use natural POMj during intensive training program and competition to accelerate muscle recovery. TRIAL REGISTRATION: ClinicalTrials.gov NCT02697903.

Ramadan fasting does not adversely affect neuromuscular performances and reaction times in trained karate athletes.

BACKGROUND: The present study aimed to investigate the concomitant effects of Ramadan intermittent fast (RIF) and muscle fatigue on neuromuscular performances and reaction times in young trained athletes. METHODS: Eight karate players (17.2 ± 0.5 years) were tested on three sessions: during a control period (S1: one week before Ramadan), and during the first (S2) and the fourth week of RIF (S3). Dietary intake and anthropometric measurements were assessed before each session. During each test session, participants performed maximal voluntary isometric contractions (MVC) and a submaximal contraction at 75 % MVC until exhaustion (T lim ) of the right elbow flexors. Surface electromyography was recorded from biceps brachii muscle during MVC and T lim . Simple (SRT) and choice (CRT) reaction times were evaluated at rest and just after T lim in a random order. RESULTS: The total daily energy (S2: +19.5 %, p < 0.05; S3: +27.4 %, p < 0.01) and water (S2: +26.8 %, p < 0.01; S3: +23.2 %, p < 0.05) intake were significantly increased during RIF. However, neither body mass nor body mass index was altered by RIF (F (2,14) = 0.80, p = 0.47 and F (2,14) = 0.78, p = 0.48, respectively). In addition, T lim (F (2,14) = 2.53, p = 0.12), MVC (F (2,14) = 0.51, p = 0.61) and associated electrical activity (F (2,14) = 0.13, p = 0.88) as well as neuromuscular efficiency (F (2,14) = 0.27, p = 0.76) were maintained during RIF. Moreover, neither SRT nor CRT was affected by RIF (F (2,14) = 1.82, p = 0.19 and F (2,14) = 0.26, p = 0.78, respectively) or neuromuscular fatigue (F (1,7) = 0.0002, p = 0.98 and F (1,7) = 3.78, p = 0.09, respectively). CONCLUSIONS: The present results showed that RIF did not adversely affect the neuromuscular performances and anthropometric parameters of elite karate athletes who were undertaking their usual training schedule. In addition, neither RIF nor neuromuscular fatigue poorly affects reaction times in elite karate athletes.

Changes in oxidative stress markers and biological markers of muscle injury with aging at rest and in response to an exhaustive exercise.

PURPOSE: The aim of this study was to evaluate whether oxidative stress markers and biomarkers of muscle injury would be affected by aging at rest and in response to an incremental exhaustive exercise. METHODS: Fifteen young (20.3 ± 2.8 years) and fifteen older adults (65.1 ± 3.5 years) performed an incremental cycle ergometer test to exhaustion. Before and after exercise, oxidative stress [superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR), ascorbic acid, α-Tocopherol, malondialdehyde (MDA)] and muscle injury [creatine kinase (CK), lactate deshydrogenase (LDH)] biomarkers were assessed. RESULTS: At rest, there was no difference in oxidative stress markers and LDH level between the groups, however CK was significantly higher in the young group than the elderly group (p<0.05). During recovery, in comparison with resting values, a significant increase in SOD (1092 ± 145.9 vs. 1243 ± 98 U/g Hb), GPX (67.4 ± 12.7 vs. 79.2 ± 15.6 U/g Hb) and GR (6.5 ± 0.9 vs. 7.7 ± 0.5 U/g Hb) activities were observed only in the young group (p<0.05). MDA has increased only in the older group (0.54 ± 0.2 vs. 0.79 ± 0.2 µmol/l) (p<0.01). CK increased in both groups (young group: 122.5 ± 22.2 vs. 161.9 ± 18.7 UI/l; older group: 88.8 ± 34.1 vs. 111.1 ± 25.9 UI/l) (p<0.01), however LDH has increased only in the young group (400.5 ± 22.2 vs. 485 ± 18.7 UI/l) (p<0.01) without alteration in the older group (382.8 ± 34.1 vs. 418.5 ± 25.9 UI/l). CONCLUSIONS: These findings indicate that aging is associated with a decrease in antioxidant efficiency and an increase in oxidative stress damage. Furthermore, older adults would not more susceptible to exercise-induced muscle injury than young people.

Effects of time-of-day and partial sleep deprivation on short-term maximal performances of judo competitors.

This study assessed the effects of partial sleep deprivation on short-term maximal performances of judokas in the morning and afternoon of the following day. In a randomized design, 12 judokas completed the maximal voluntary contraction, the handgrip, and the Wingate tests before and after a judo combat. Measurements were performed at 09:00 and 16:00 hours after a reference-normal sleep night and 2 conditions of 4-hour partial sleep deprivation timed at the beginning (SDB) or at the end of the night (SDE). The results showed that muscle power and strength were significantly higher at 16:00 than 09:00 hours (p < 0.05). These diurnal variations disappeared after SDB and SDE and after the combat. In addition, SDE resulted in significant decreases of short-term maximal performance in the afternoon (p < 0.01). In conclusion, SDE decreased muscle strength and power at 16:00 hours and, therefore, might have blunted the diurnal variations of short-term maximal exercise. Thus, early rising is more detrimental than late bedtime to muscle strength and power for judo athletes when competitions are scheduled in the afternoon hours.