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Abstrak :
The maximal accumulated oxygen deficit (MAOD), which is the gold standard for anaerobic energy metabolism capacity, requires multiple tests for evaluation that impose a heavy load on subjects. The maximal accumulated blood lactate (AbLa) concentration is also a measure of anaerobic energy metabolism capacity, and is related to the accumulated oxygen deficit (AOD). Thus, AOD has been estimated by using AbLa (3.0 mL02 * kg-1 * mM"1), but it is unclear if this coefficient is suitable for measurement of supramaximal running of athletes. The purpose of this study was to clarify the estimated expression of AOD by using AbLa from the relationship between MAOD and AbLa during supramaximal running in middle-distance run¬ners. Eleven male middle-distance runners (800m running velocity: 425.3 ± 7.3 m-min'1) took part in this study. They performed three running tests (maximal, submaximal and supramaximal running test) to evaluate MAOD and AbLa. MAOD and AbLa were 56.6 ± 6.0 mL02 * kg'1 and 9.9 ± 1.1 mmolL'1, respectively. We observed a significant positive relationship between MAOD and AbLa (r = 0.73); the regression line equation was y = 3.58x + 18.6. Results showed that the AOD per mM of the AbLa of athletes was 3.58 mL02*kg 1, which was 19% higher than the conventional coefficient value.

Abstrak :
ABSTRACT
The objectives of this study were 1) to quantify the differences in body densities and percent body fat using various methods for evaluating body composition (e.g., underwater weighing (UWW), air displacement plethysmography (ADP), skinfold caliper (SKF) measurement, ultrasound (US), bioelectrical impedance analysis (BIA), and dual-energy x-ray absorptiometry (DXA)), and 2) to examine the relationship between trends of the differences in body density and percent body fat obtained by these methods and characteristics of morphology and body composition. To this end, the body compositions of 73 healthy male adults were measured using UWW, ADP, SKF, US, and BIA. Twenty-seven of these 73 subjects underwent further measurement using DXA. Differences in body densities determined with ADP, SKF, and US were compared with those measured using UWW as a reference, and the differences in percent body fat estimated with UWW, ADP, SKF, US and BIA were compared with those measured by DXA as a reference. The results of this study indicate that 1) ADP is useful as a method for evaluating body density, as the results differed insignificantly from the reference method and showed no systematic errors due to differences in morphological characteristics and body composition, and 2) UWW measurements exhibited the smallest difference in percent body fat from the reference method, however, more than in any other method, there were systematic errors due to differences in morphological characteristics and body composition, specifically, trunk composition.

Abstrak :
Humans perceive their body posture, size, and position in space even when they do not look at their body. The ability to perceive the body correctly is essential to move accurately in space. The purpose of this review is to introduce the reader to the latest views on the role of peripheral afferent signals in the generation and alteration of perception of the body. First, the contribution of proprioceptive and cutaneous signals to perception of the body is introduced. Common methods to investigate these signals are muscle vibration, skin stretch, or electrical stimulation. These methods provide evidence that the perception of the body is flexible. Second, effects of multisensory integration on perception of the body are described. The combination of visual, tactile, proprioceptive, and auditory signals alter the perception of the body, suggesting that multiple sensory signals contribute to perception of the body. Third, the distortion of perception of the body after the loss of sensory signals is reviewed. Anesthesia or amputation of limbs, as well as experimentally-induced disintegration of sensory signals drastically alter the perception of the body. Fourth, neural mechanisms underlying the generation, or alteration, of perception of the body is described. The premotor and parietal cortices play a key role in perception of the body, as they are involved in multisensory integration. In the final section of the review, implications of the ways sensory information shapes perception of our body are discussed for athletic performance.

Abstrak :
The health values of exercise and eating are separately established as two independent pillars for human life. However, a substantial amount of evidence shows the physiological crosstalk by which exercise might be associated with hunger and satiety, as regulated by gut hormones. A single bout of exercise tends to suppress the blood levels of orexigenic acylated ghrelin (AG) and to increase the levels of anorectic hormones like peptide YY (PYY) and gluca-gon-like peptide-1 (GLP-1). It was reported that, while sustained physical activity increases the drive to eat in the fasting state, this seems to be compensated by an improved satiety response to a meal through changes in the gut hormone systems. A few studies reported exercise-induced reductions in the neural responses to food-related cues in higher brain center networks involved in the attentional, emotional and cognitive functions. The present review introduces the latest research on the effects of various types of exercise on the neuroendocrine networks related to hunger, satiety, appetite, and responses to food-related cues, suggesting the physiological ratio¬nale for the linkage between exercise and eating in humans. Next, the possibilities of the brain science of exercise and eating for improvements in modem human health in various generational groups are discussed.

Abstrak :
Effective behaviors optimized for various situations are enabled by various sensory information. Flow does the brain deal simultaneously with information from different sensory systems? Investigation of multisensory processing began from neuroanatomical and neurophys iological studies at the level of single neurons. Accumulation of knowledge concerning neurons and progress in recording techniques of human brain activity have led to a massive expansion in recent neuroscientific studies using various combinations of brain activity recording and cognitive tasks. In this paper, we briefly review recent neuroscientific studies related to multisensory convergence and interaction, focusing on electrophysiological and imaging studies in humans.

Abstrak :
Skeletal muscle stem cells, known as satellite cells, participate in postnatal skeletal muscle growth, regeneration, and hypertrophy. They are quiescent in the resting state, but are activated after muscle injury, and subsequently replicate and fuse into existing myofibers. The behavior of satellite cells during muscle regeneration is regulated by extrinsic factors, such as the extracellular matrix, mechanical stimuli, and soluble factors. Myokines, muscle-derived secretory factors, are important regulators of satellite cell activation, proliferation, and differen¬tiation. It is well known that muscle injury induces the release of various growth factors from myofibers, and these growth factors affect satellite cells. It has recently been shown that myokines secreted from myofibers without cell damage also regulate satellite cell functions. Here, we summarize myokines with known roles in the regulation of satellite cells and the mechanism underlying this regulatory process.

Abstrak :
Sports and physical activity provide multiple social and health benefits to participants, but may also increase the risk of developing musculoskeletal pain and injuries, especially in skeletally immature adolescents. This review outlines the 1) measurement and prevalence of musculoskeletal pain in adolescents, 2) dose-response relationship between the organized sports activity and musculoskeletal pain, 3) high risk population, based on our previously published epidemiological studies in Japan, and finally, 4) prevention strategy and its evaluation. In our school-based cohort study in Unnan, Shimane, a total of 2403 adolescents aged 12 to 18 years responded to two serial surveys, conducted 1 year apart. The prevalence of overall pain was 27.4% (lower limbs: 15.4%, upper limbs: 9.5%, and lower back: 8.5%). Sports activity had a clear linear association with musculoskeletal pain prevalence and risk. The more the adolescents played sports, the more likely they were to have pain or develop pain. Each 1 hour/week of additional sports activity time was associated with a 3% higher probability of having or developing pain. Some population groups were at higher risk of musculoskeletal pain, such as overweight adolescents and regular players with fewer teammates. To optimize the safety and benefits of organized sports activity for adolescents, prevention of musculoskeletal pain should be an important consideration. More observational and intervention studies with quality designs and development of a national surveillance system for (youth) acute and chronic sports injuries are needed in Japan.

Abstrak :
During exercise, levels of several hormones are acutely increased in the blood. We previously reported that pre-exercise ingestion of a specific combination of amino acids (arginine, alanine, and phenylalanine; A-mix) increases fat mobilization and ketone body synthesis by increasing secretion of adrenalin and glucagon in healthy active young men. Herein, we sought to determine whether this acute hormone response could be induced upon administration of A-mix combined with exercise in patients with obesity during periods of low-intensity exercise. We performed a randomized crossover study of eleven middle-aged men with obesity without regular exercise habits, administered either A-mix (3 g/dose) or a placebo (3 g of dextrin/dose). Thirty minutes after ingestion, each subject subsequently performed workload tests on a cycle ergometer at 40% of peak oxygen consumption for 1 h. Following oral intake of A-mix, the concentration of plasma ketone bodies was significantly increased during exercise. This was accompanied by a significant increase in the area under the concentration-time curve for glucagon. Taken together, these results indicate that pre-exercise ingestion of the A-mix supplement significantly accelerated hepatic ketone body synthesis via stimulation of glucagon secretion during exercise in men with obesity.