These results suggest that the attenuation of muscle deoxygenation near VO2peak is related to and precedes changes in neuromuscular activity under normoxic and hypoxic conditions.

Background Severe rapid weight loss (RWL) induces a decrease in muscle glycogen (mGly). Nevertheless, adequate carbohydrate intake after RWL has not been reported to optimize muscle glycogen following a weigh-in the evening until a wrestling tournament morning. The purpose of this study was to investigate the effect of an overnight high-carbohydrate recovery meal of 7.1 g kg−1 following RWL on mGly concentration. Methods Ten male elite wrestlers lost 6% of their body mass within 53 h and then subsequently ate three meals, within 5 h, containing total of 7.1 g kg−1 of carbohydrates. mGly was measured by 13C-magnetic resonance spectroscopy before (BL) and after RWL (R0) at 2 h (R2), 4 h (R4), and 13 h (R13) after initiating the meal. Body composition, muscle cross-sectional area, and blood and urine samples were collected at BL, R0, and R13. Results Body mass decreased by 4.6 ± 0.6 kg (p < 0.05) and did not recover to BL levels in R13 (− 1.7 ± 0.6 kg, p < 0.05). Likewise, mGly by 36.5% ± 10.0% (p < 0.05) and then did not reach BL levels by R13 (p < 0.05). Conclusion A high-carbohydrate meal of 7.1 g kg−1 after 6% RWL was not sufficient to recover mGly during a 13 h recovery phase. Participating in high-intensity wrestling matches with an mGly concentration below normal levels is maybe undesirable.

It is important to clarify trophic dynamics in marine ecosystems for management of the fishing ground. Organic carbon sources and trophic position of pelagic fishes in the coastal waters of the south-eastern Izu Peninsula, Japan, were examined on the basis of carbon and nitrogen stable isotope distributions. The d 13 C of the fishes was mostly distributed from -19 to -16‰ for nektonic fishes (13 species of adults and immatures) and planktonic fishes (10 species of larvae and juveniles), close to the d 13 C values of particulate organic matter and planktonic decapods. These d 13 C signatures for the inhabitants of the water column were in contrast with the high d 13 C values (mainly -16 to -13‰) for demersal fishes of Scorpaeniformes and benthic polychaetes collected in the surf zone. These results indicate that nektonic and planktonic fishes depend on phytoplankton for carbon supply. The d 15 N signatures suggest that the trophic position ranged 3.1-4.5 for the nektonic fishes and 2.9-3.7 for the planktonic fishes, premised on trophic level 3 for larval Japanese anchovy Engraulis japonicus. Thus, planktivorous fishes should be mainly assigned to trophic levels 3 and 4 in this area.KEY WORDS: carbon source, d 13 C, d 15 N, Izu Peninsula, pelagic fish, stable isotope, trophic position.

These findings suggest that denervation-induced capillary regression may be associated with down-regulation of VEGF and angiopoietin signalling.

There is marked diurnal variation in the glycogen content of skeletal muscles of animals, but few studies have addressed such variations in human muscles. (13)C MRS can be used to noninvasively measure the glycogen content of human skeletal muscle, but no study has explored the diurnal variations in this parameter. This study aimed to investigate whether a diurnal variation in glycogen content occurs in human muscles and, if so, to what extent it can be identified using (13)C MRS. Six male volunteers were instructed to maintain their normal diet and not to perform strenuous exercise for at least 3 days before and during the experiment. Muscle glycogen and blood glucose concentrations were measured six times in 24 h under normal conditions in these subjects. The glycogen content in the thigh muscle was determined noninvasively by natural abundance (13)C MRS using a clinical MR system at 3 T. Nutritional analysis revealed that the subjects' mean carbohydrate intake was 463 ± 137 g, being approximately 6.8 ± 2.4 g/kg body weight. The average sleeping time was 5.9 ± 1.0 h. The glycogen content in the thigh muscle at the starting point was 64.8 ± 20.6 mM. Although absolute and relative individual variations in muscle glycogen content were 7.0 ± 2.1 mM and 11.3 ± 4.6%, respectively, no significant difference in glycogen content was observed among the different time points. This study demonstrates that normal food intake (not fat and/or carbohydrate rich), sleep and other daily activities have a negligible influence on thigh muscle glycogen content, and that the diurnal variation of the glycogen content in human muscles is markedly smaller than that in animal muscles. Moreover, the present results also support the reproducibility and availability of (13)C MRS for the evaluation of the glycogen content in human muscles.