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Study aim: To investigate the effect of fatigue, induced by a volleyball training game on the risk of Anterior Cruciate Ligament (ACL) injury. Material and methods: Thirteen female volleyball college athletes, ages 18 to 21 years old, completed jump landings from a box 30 cm height, prior and post a 60-minute volleyball training game. The clinical tool Landing Error Scoring System (LESS) was employed in order to evaluate the technique of landing prior and post the game. The level of fatigue induced by the volleyball game was assessed by vertical jump test and Borg Rating of Perceived Exertion (RPE) Scale pre and post-game. In order to compare measurements pre and post-game t-tests for dependent samples were used. Results: Participants performed lower vertical jumps post-game with a Confidence Interval of 26.2 ± 2.3 cm (pre-game) and 24.9 ± 2.2 cm (post game). The difference between pre and post-game was found to be statistically significant with a t12 = 2.55 and a p-value of 0.026. In the case of assessing fatigue, the Borg RPE scale scores were found to be statistically significant (t12 = 14.05, p < 0.001) higher post-game (10.2 ± 0.6), as compared to pre-game (6.5 ± 0.4). Similarly, LESS scores increased significantly (t12 = 2.21, p = 0.047), post-game (6.3 ± 1.1) compared to pre-game (5.8 ± 1.0) that prove poorer landing ability. Conclusion: It seems that a short duration volleyball training game induces fatigue and negatively affects the jumping and landing ability.

The present study investigated the effect of Corinthian currant pre-exercise supplementation on metabolism, performance and blood redox status during, and after prolonged exercise. Eleven healthy participants (21-45y) performed a 90-min constant-intensity (60–70% VO2max) submaximal-trial, plus a time-trial (TT) to exhaustion (95% VO2max) after consuming an isocaloric (1.5g CHO/kg BM) amount of randomly assigned Corinthian currant or glucose-drink, or water (control). Blood was drawn at baseline, pre-exercise, 30min, 60min, 90min of submaximal-trial, post-TT, and 1h post-TT. Post-ingestion blood glucose (GLU) under Corinthian currant was higher compared with water, and similar compared with glucose-drink throughout the study. Respiratory quotient under Corinthian currant was similar with glucose-drink and higher than water throughout the submaximal trial. Accordingly, higher CHO and lower fat oxidation were observed under Corinthian currant compared with water. The TT performance was similar betwee...

Spirulina plantensis is a popular supplement which has been shown to have antioxidant and performance enhancing properties. The purpose of this study was to evaluate the effects of spirulina supplementation on (a) redox status (b) muscle performance and (c) muscle damage following an eccentric bout of exercise that would induce muscle damage. Twenty-four healthy, recreationally trained males participated in the study and were randomly separated into two groups: a spirulina supplementation (6 g per day) and a placebo group. Both groups performed an eccentric bout of exercise consisting of 5 sets and 15 maximum reps per set. Blood was collected at 24, 48, 72 and 96 h after the bout and total antioxidant capacity (TAC) and protein carbonyls (PC) were assessed in plasma. Delayed onset muscle soreness (DOMS) was also assessed at the same aforementioned time points. Eccentric peak torque (EPT) was evaluated immediately after exercise, as well as at 24, 48, 72 and 96 h post exercise. Redox status indices (TAC and PC) did not change significantly at any time point post exercise. DOMS increased significantly 24 h post exercise and remained elevated until 72 h and 96 h post exercise for the placebo and spirulina group, respectively. EPT decreased significantly and immediately post exercise and remained significantly lower compared to baseline until 72 h post exercise. No significant differences between groups were found for DOMS and EPT. These results indicate that spirulina supplementation following a muscle damaging protocol does not confer beneficial effects on redox status, muscle performance or damage.

Notions of "optimal" posture are widespread in modern society and strongly interconnected with preconceived beliefs.To quantitatively evaluate spinal posture among members of the community during habitual sitting, and when asked to assume an "optimal" posture.Observational study.Marker-based kinematic analyses of the head, spine, and pelvis were conducted on 100 individuals. Habitual sitting posture and self-perceived "optimal" posture, and whether participants believed that their habitual sitting reflected an "optimal" posture, were evaluated. The Wilcoxon signed-rank test assessed angular differences between the two postures adopted. Exploratory post-hoc analyses were conducted by using the Mann-Whitney U test to assess differences between genders.None of the participants stated that their habitual sitting was "optimal". Statistically significant differences were observed in most of the measured angles (p 0.001) between habitual and self-perceived "optimal" posture. In habitual sitting posture, a significant interaction with gender was found only in the thoracolumbar (p 0.05) and pelvic (p 0.001) angles, with small effect sizes. In self-perceived "optimal" posture females were more extended in the head, upper thoracic, lower thoracic, lumbar and pelvic (p 0.01) regions, than the males.A group of young, asymptomatic participants, consistently changed their habitual sitting posture to a more upright posture when asked to assume an "optimal" sitting posture, although the amount of change observed varied between spinal regions. These findings also highlight gender differences in not just habitual sitting posture, but also the degree to which habitual sitting posture is modified when trying to assume an "optimal" sitting posture.

Exercise-induced skeletal muscle microtrauma is characterized by loss of muscle cell integrity, marked aseptic inflammatory response, and oxidative stress. We examined if iron supplementation would alter redox status after eccentric exercise. In a randomized, double blind crossover study, that was conducted in two cycles, healthy adults (n=14) and children (n=11) received daily either 37 mg of elemental iron or placebo for 3 weeks prior to and up to 72 h after an acute eccentric exercise bout. Blood was drawn at baseline, before exercise, and 72 h after exercise for the assessment of iron status, creatine kinase activity (CK), and redox status. Iron supplementation at rest increased iron concentration and transferrin saturation (p<0.01). In adults, CK activity increased at 72 h after exercise, while no changes occurred in children. Iron supplementation increased TBARS at 72 h after exercise in both adults and children; no changes occurred under placebo condition. Eccentric exercise decreased bilirubin concentration at 72 h in all groups. Iron supplementation can alter redox responses after muscle-damaging exercise in both adults and children. This could be of great importance not only for healthy exercising individuals, but also in clinical conditions which are characterized by skeletal muscle injury and inflammation, yet iron supplementation is crucial for maintaining iron homeostasis. This study was registered at Clinicaltrials.gov Identifier:NCT02374619.

Studies of the fat mass and obesity-associated (FTO) gene provide compelling evidence of genetic variation in the general population that influences fat levels and obesity risk. Studies of the interaction between genetic and environmental factors such as physical activity (PA) will promote the understanding of how lifestyle can modulate genetic contributions to obesity. In this study, we investigated the effect of FTO genotype, and interactions with PA or energy intake, in young children and adolescents. In all, 1-5-year-old children from the Growth, Exercise and Nutrition Epidemiological Study in preSchoolers (GENESIS) study (N=1980) and 11-18-year-old Greek adolescents (N=949) were measured for adiposity-related phenotypes and genotyped at the FTO single-nucleotide polymorphism (SNP) marker, rs17817449. Adolescents were classified as physically active or inactive based on self-reported levels of PA. In adolescents, FTO genotype influenced weight (P=0.001) and BMI (P=0.007). There was also a significant SNP(*)PA(*)gender interaction (P=0.028) on BMI, which reflected the association between FTO genotype and BMI in males (P=0.016), but not females (P=0.15), and significant SNP(*)PA interaction in males (P=0.007), but not females (P=0.74). The FTO genotype effect was more pronounced in inactive than active males. Inactive males homozygous for the G allele had a mean BMI 3 kg/m(2) higher than T carriers (P=0.008). In the GENESIS study, no significant association between FTO genotype and adiposity was found. The present findings highlight PA as an important factor modifying the effect of FTO genotype.

The procedure for blood sampling in doping control, implemented for the first time as part of the official foren- sic testing programme in the Athens 2004 Summer Olympic Games is described. 743 whole blood and serum samples from 37 sports were analyzed. In serum human growth hormone and hemoglobin based oxygen carriers were screened for. In whole blood samples heterologous blood transfusion was detected. Routine haematological parameters (hematocrit, haemoglobin) were followed in a very limited range only in Modern Pentathlon under the responsibility of the respective International Federation. The majority of the blood samples collected concerned events in athletics. Endurance sports accounted for 81% of the whole blood sampling. Athletics, swimming and rowing represented 55% of the serum samples analyzed. Extension of testing for oxygen transport enhancing agents in anaerobic sports should be seriously considered by future organizers and the International Olympic Committee. The mean time for an athlete to report to the Doping Control Station for blood collection was 6.1 hours; 27% of the ath- letes tested (from 19 sports) failed to appear within the 12-hours time limit set. Training of the phlebotomists was proven effective. Only 25 athletes of those tested (3%) reported to have felt uncomfort- able. The majority of complaints (47%) concerned the prolonged waiting period and the long blood collection time (48%). Finally, an earlier agreement between all involved parties, attempts to decrease the time to appear at the site of blood col- lection and shortening of the duration of blood collection and sealing of the samples are recommended.

The functional allele (577R) of ACTN3, which encodes human alpha-actinin-3, has been reported to be associated with elite athletic status and with response to resistance training, while the nonfunctional allele (577X) has been proposed as a candidate metabolically thrifty allele. In a study of 992 adolescent Greeks, we show that there is a significant association (P=0.003) between the ACTN3 R577X polymorphism and 40 m sprint time in males that accounts for 2.3% of phenotypic variance, with the 577R allele contributing to faster times in an additive manner. The R577X polymorphism is not associated with other power phenotypes related to 40 m sprint, nor with an endurance phenotype. Furthermore, the polymorphism is not associated with obesity-related phenotypes in our population, suggesting that the 577X allele is not a thrifty allele, and thus the persistence of this null allele must be explained in other terms.

The purpose of this study was to examine the relationship between vertical jumping performance and isokinetic moment of force of knee extensors, hip extensors and ankle plantar flexors in adult males. Twenty-nine males performed squat and counter movement jumps on an Egrojump device. The peak jumping height and the total work (height x body mass) were used as indicators of vertical jump performance. The subjects also performed three submaximal and three maximal isokinetic efforts of the hip extensors, knee extensors and ankle plantarflexors at angular velocities of 60, 120 and 180°.s -1 on Cybex Norm Dynamometer. Pearson's product correlation tests indicated that there was a significant (p 0.05). Multiple regression analysis indicated that linear combinations of isokinetic torques accounted for 38% and 42% of the countermovement and squat jumping height variance, respectively. In contrast, regression models using isokinetic torques could predict jumping work accounting for 75% (counter movement jump) and 69% (squat jump) of the variance. The above results indicate that there is a moderate to high relationship between isokinetic knee and hip extension torques and vertical jump performance parameters, especially when jumping height is multiplied by subject's body weight. Furthermore, it appears that when using a linear combination of isokinetic torques from hip and knee joint muscle groups the multiple relationship between isokinetic tests and jumping performance is higher.

To gather data and examine the use by elite Olympic athletes of food supplements and pharmaceutical preparations in total and per sport, country, and gender.Survey study.Athens 2004 Olympic Games (OG).Data from 2 sources were collected: athletes' declaration of medications/supplements intake recorded on the Doping Control Official Record during sample collection for doping control, and athletes' application forms for granting of a therapeutic use exemption (TUE) and through the abbreviated TUE process (aTUE).Classification of declared food supplements according to the active ingredient and medications according to therapeutic actions and active compounds.24.3% of the athletes tested for doping control declared no use of medications or food supplements. Food supplements (45.3%) continue to be popular, with vitamins (43.2%) and proteins/aminoacids (13.9%) in power sports being most widely used. Nonsteroidal antiinflammatory agents and analgesics were also commonly used by athletes (11.1% and 3.7%, respectively). The use of the hemoderivative actovegin and several nonprohibited anabolic preparations are discussed. The prevalence of medication use for asthma and the dangers of drug interactions are also presented.Laboratory analysis data reveal that of the aTUEs received for inhaled glucocorticosteroids, only budesonide was detectable in significant percentage (10.0%). Only 6.5% of the 445 athletes approved to inhale beta2-agonists led to an adverse analytical finding.This review demonstrates that overuse of food supplements was slightly reduced compared to previous OGs and a more rational approach to the use of medication is being adopted.

Genetic variation in the human Angiotensin I-Converting Enzyme (ACE) gene has been associated with many heritable traits, including physical performance. Herein we report the results of a study of several physical, physiological and skill parameters and lifestyle in 1027 teenage Greeks. We show that there is a strong association (P less than 0.001) between the ACE I/D (insertion/deletion) polymorphism and both handgrip strength and vertical jump in females, homozygotes for the I-allele exhibiting higher performance-related phenotype scores, accounting for up to 4.5% of the phenotypic variance. The association is best explained by a model in which the D-allele is dominant, with the mean phenotypic value in the I/D heterozygotes being close to that of the mean of the DD homozygotes. The association acts across the phenotype distribution in a classical polygenic manner. Other polymorphisms that define major ACE haplotypes in European populations (rs4424958, rs4311) show weaker associations with these performance-related phenotypes than does I/D. Similarly, diplotypes defined by these polymorphisms do not explain significantly larger amounts of the variance than I/D alone. As ACE I/D is the polymorphism most strongly associated with circulating ACE activity in European populations, we propose that the functional allelic differences that influence ACE activity also mediate the associations with the performance-related phenotypes studied here.

Genetic variation in the human angiotensin I-converting enzyme (ACE) gene has been associated with many heritable traits, including obesity. Herein, we report the results of a study of obesity-related phenotypes and lifestyle in 1016 teen-aged Greeks. We show that there is a strong association (p = 0.001) between subcutaneous fat and the ACE insertion/deletion (I/D) polymorphism in females, possession of genotypes containing the D allele being associated with increased fat thickness. This association is strongest in females who participate in no extra exercise and accounts for 6.5% of the phenotypic variance in fat thickness by ANOVA. The association is additive, with the mean phenotypic values in heterozygotes intermediate between the means of the two homozygotes, and the association acts at both extremes of the fat thickness distribution in a classical polygenic manner. Other ACE polymorphisms (rs4424958, rs4311) that define major haplotypes in European populations fail to provide stronger associations with the subcutaneous fat phenotype. Because ACE I/D is the polymorphism most strongly associated with circulating ACE levels in European populations, we propose that the functional allelic differences that influence circulating ACE levels also mediate the associations with the obesity-related phenotypes studied here.

Objective: The aim of this study was to investigate physical fitness in relation to fatness in urban and rural Greek children by means of allometric scaling. Methods: The sample consisted of 360 (189 urban and 171 rural; age 12.3±0.42 years) boys and 247 (125 urban and 122 rural; age 12.3±0.43 years) girls. The sample was highly representative (32–64%) of all 12 year old children registered in the prefecture of Trikala, Greece. All volunteers were assessed for BMI and % body fat, as well as sit and reach, basketball throw (BT), vertical jump (VJ), handgrip strength (HG), 40 m sprint, agility run, and 20 m shuttle run. To correct for possible associations between fatness and fitness, a single cause allometric scaling was employed using the natural logarithms (ln) of fitness parameters that were significantly correlated with the ln body fat. Results: Independent-samples t tests revealed that VJ (p

Many exercise models have demonstrated associations between eccentric muscle actions and muscle damage. However, the magnitude of muscle damage varies among the models. It appears that responses to eccentric exercise are different between leg and arm muscles but this has not been systematically clarified. This study compared leg and arm eccentric exercises of the same relative intensity for indices of muscle damage. Eleven healthy untrained males [Age: 21.2 (1.0) years, Height: 179.4 (3.0) cm, Weight: 78.4 (3.1) kg] performed a sub-maximal eccentric exercise of the knee extensors (LEGS) and the elbow flexors (ARMS), separately. Both LEGS and ARMS consisted of six sets of 12 repetitions with an intensity corresponding to 75% of the predetermined maximal eccentric peak torque (EPT) of each muscle. Range of motion (ROM), delayed onset muscle soreness (DOMS), serum creatine kinase (CK) and lactate dehydrogenase (LDH) activities, myoglobin (Mb) concentration, and muscle strength [EPT and isometric peak torque (IPT)] were assessed before and 24, 48, 72, and 96 h following exercise. Significant (P < 0.05) changes in DOMS and ROM were observed up to 96 h after both exercise bouts, and the magnitude of the change was similar between LEGS and ARMS. Increases in CK and Mb were significantly (P < 0.05) larger after ARMS than LEGS at 72 and 96 h post-exercise. EPT and IPT were significantly (P < 0.05) lower than the baseline up to 96 h post-exercise for ARMS but were fully recovered by 96 h post-exercise for LEGS. Decreases in muscle strength were significantly (p < 0.05) larger following ARMS than LEGS at 48, 72, and 96 h post-exercise for EPT, and from 24 h to 96 h post-exercise for IPT. These results suggest that the magnitude of muscle damage is greater and the recovery of muscle function was slower after eccentric exercise of arm elbow flexors than the knee extensors.

We investigated the effects of a single bout of aerobic and resistance exercise of similar relative intensity and duration on resting energy expenditure (REE) and substrate utilisation. Ten young healthy males volunteered [age 22 (1.8) years, weight 76 (7.9) kg, height 176 (4.1) cm, percentage body fat 10.5 (4.0)%; mean (SEM)]. They randomly underwent three conditions in which they either lifted weights for 60 min at 70-75% of 1-RM (WL), ran for 60 min at 70-75% of maximal oxygen intake (R) or did not exercise (C). REE and substrate utilisation, determined via respiratory exchange ratio ( R), were measured prior to exercise, and 10, 24, 48 and 72 h post-exercise. It was revealed that REE was significantly elevated ( P