Background This study aimed to investigate the effect of supplementation of fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the damage of the biceps brachii after eccentric contractions (ECCs) of the elbow flexors, particularly focusing on muscle stiffness. Methods Sixteen men were included in this double-blind, placebo-controlled, parallel design study and the participants were randomly assigned to the EPA and DHA supplement group (EPA, n = 8) and placebo group (PL, n = 8). They consumed either EPA 600 mg and DHA 260 mg per day or placebo supplement for 8 weeks prior to exercise. Moreover, they performed six sets of 10 ECCs at 100% maximal voluntary contraction (MVC) using a dumbbell. Changes in MVC torque, range of motion (ROM), upper arm circumference, muscle soreness, muscle echo intensity, and muscle stiffness were assessed before exercise; immediately after exercise; and 1, 2, and 5 days after exercise. Results MVC torque and ROM were significantly higher in the EPA group than in the PL group after ECCs ( p < 0.05). Muscle soreness, upper arm circumference, and muscle echo intensity were significantly higher in the PL group than in the EPA group after ECCs ( p < 0.05). In addition, muscle stiffness at 150° was significantly higher in the PL group than in the EPA group immediately after ECCs ( p < 0.05). Conclusion The present study showed that EPA and DHA supplementation has a positive role in inhibiting muscle stiffness after ECCs. Trial registration This trial (UMIN000028165) was registered on 10th/July/2017.

Purpose Prolonged sitting impairs leg endothelial function, which seems to be mediated by a sustained reduction in blood flow-induced shear stress. However, whether regular endurance training is effective in preventing sitting-induced leg endothelial dysfunction remains largely unknown. Herein, we tested the hypothesis that sitting-induced leg endothelial dysfunction is prevented in high endurance-trained individuals. Methods The endurance-trained group comprised 10 male collegiate cyclists, and the untrained group comprised nine men with no regular endurance training. Peak oxygen uptake (V˙O2peak) was initially determined in all participants using incremental exercise test (37.9 ± 4.7 mL·min−1·kg−1 in the untrained group versus 60.8 ± 3.6 mL·min−1·kg−1 in the endurance-trained group). At second visit, the popliteal artery flow-mediated dilation (%FMD) was assessed before and after a 3-h sitting period. During the sitting period, the popliteal artery diameter and blood velocity were measured every hour. Results The popliteal artery blood flow and shear rate were significantly and similarly reduced during the sitting period in both groups (P < 0.001). In a 3-h sitting, a significant impairment in popliteal artery %FMD was observed in the untrained group (P = 0.003), but it was prevented in the endurance-trained group (P < 0.196). Conclusions In conclusion, the present study revealed that sitting-induced leg endothelial dysfunction is preventable in endurance-trained individuals.

Evolution of the statistical distribution of density eld is investigated by means of a counts-in-cells method in a low-density cold-dark-matter simulated universe. Four theoretical distributions, i.e. the negative binomial distribution, the lognormal distribution, the Edgeworth series and the skewed lognormal distribution, are tested to t the calculated distribution function, and it is shown that only the skewed lognormal distribution of second and third order can describe the evolution of the statistical distribution perfectly well from the initially Gaussian regime to the present stage. The eects of sparse sampling is also investigated and it is discussed that one should use a sample with number density of galaxies larger than 0:01h 3 Mpc 03 in order to recover underlying density distribution.

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