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.

The functional allele (577R) of ACTN3, which encodes human a-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 ¼ 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.

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,0.05) was significantly higher in boys living in urban settings compared to their rural counterparts. Similarly, BT was found to be significantly better (p,0.05) in urban girls, whereas HG was significantly higher (p,0.05) in rural girls. Conclusion: Considering that (a) only three out of the 14 possible cases (seven fitness parameters for boys and seven for girls) were significantly different between urban and rural children, and (b) these differences were not uniformly distributed in children living in either urban or rural environments, it is concluded that the place of residence has no clear impact on physical fitness as studied herein.

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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.