Lower trunk muscle activity-induced alignment and cop position during single-leg standing.

[Purpose] The purpose of this study was to clarify fundamental changes induced by lower trunk muscle contraction during single-leg standing. [Subjects and Methods] Ten healthy normal males participated in this study. All subjects could accurately perform lower trunk muscle contraction-type Abdominal Expansion (AE), Abdominal Bracing (AB), and Abdominal Cave-in (AC). The alignment and position of the center of foot pressure (COP) during single-leg standing with SLR and step position after rotating the body from single-leg standing with maximum SLR were measured in each lower trunk muscle contraction type. [Results] When AC was performed during single-leg standing with SLR, the SLR angle increased, COP shifted backward, and the posterior tilt angle of the trunk and cross step distance decreased. [Conclusion] It was assumed that AC during wind-up increases the angle of lower limb elevation and decreases the posterior tilt angle of the trunk and cross step distance.

Effect of the volume of fluid ingested on urine concentrating ability during prolonged heavy exercise in a hot environment.

This study examined the effect of the volume of fluid ingested on urine concentrating ability during prolonged heavy exercise in a hot environment at low levels of dehydration. Seven healthy males performed 105 min of intermittent cycle exercise at 70% maximum oxygen uptake (32°C, 60% relative humidity) while receiving no fluid ingestion (NF), voluntary fluid ingestion (VF), partial fluid ingestion equivalent to one-half of body mass loss (PF), and full fluid ingestion equivalent to body mass loss (FF). Fluid (5°C, 3.4% carbohydrate, 10.5 mmol·L(-1) sodium) was ingested just before commencing exercise and at 15, 33, 51, 69, and 87 min of exercise, and the total amount of fluid ingested in PF and FF was divided into six equal volumes. During exercise, body mass loss was 2.2 ± 0.2, 1.1 ± 0.5, 1.1 ± 0.2, and 0.1 ± 0.2% in NF, VF, PF, and FF, respectively, whereas total sweat loss was about 2% of body mass in each trial. Subjects in VF ingested 719 ± 240 ml of fluid during exercise; the volume of fluid ingested was 1.1 ± 0.4% of body mass. Creatinine clearance was significantly higher and free water clearance was significantly lower in FF than in NF during exercise. Urine flow rate during exercise decreased significantly in NF. There were significant decreases in creatinine and osmolar clearance and was a significant increase in free water clearance during exercise in NF and VF. Creatinine clearance decreased significantly and free water clearance increased significantly during exercise in PF. There was no statistical change in urinary indices of renal function during exercise in FF. The findings suggest that full fluid ingestion equivalent to body mass loss has attenuated the decline in urine concentrating ability during prolonged heavy exercise in a hot environment at low levels of dehydration. Key pointsDuring prolonged heavy exercise in a hot environment at low levels of dehydration, fluid ingestion equivalent to body mass loss results in no changes in urinary indices of renal function.Fluid ingestion equivalent to body mass loss can attenuate the decline in urine concentrating ability during exercise.Ad libitum or voluntary fluid ingestion is ineffective in reducing the decline in urine concentrating ability during exercise.

Interferential electric stimulation applied to the neck increases swallowing frequency.

Swallowing disorders are a common complaint among the elderly. Recently, surface electrical stimulation applied to the neck region has received increased attention as a new modality to treat pharyngeal dysphagia. Previous reports used pulsed current at a frequency range of 1-120 Hz. Kilohertz-frequency alternating currents (ACs) have not been tested for treating dysphagia. Therefore, we evaluated the effects of interferential currents (IFCs), the most popular modality of amplitude-modulated kilohertz-frequency ACs in clinical practice, on the swallowing reflex in healthy subjects. We found that IFC stimulation at the sensory threshold with 50-Hz modulation significantly increased the number of swallows without any discomfort, but pure AC stimulation at the carrier frequency did not have a significant effect. There was no statistically significant difference in the time course of the number of swallows among 1,000-, 2,000-, 4,000-, and 6,000-Hz carrier frequencies. The number of swallows remained increased during the 15-min IFC stimulation, suggesting that IFC stimulation facilitates the swallowing reflex without adaptation, at least during this stimulation period. We suggest that an IFC stimulation or a low-frequency, modulated kilohertz AC stimulation, which would be more comfortable than pulsed currents, is an alternative stimulation mode for treating pharyngeal dysphagia.

In-match physical demands on elite Japanese rugby union players using a global positioning system.

OBJECTIVES: Our aim of this study was to quantify the physical demands of elite rugby union players by each position as a step towards designing position-specific training programme using a Global Positioning System/accelerometer system. METHODS: This study was performed as a retrospective observational study. Data were obtained from 45 official matches. The sample size used for the analysis was 298. The per-match total distances, accelerations and impacts were calculated and statistically compared for the forwards and backs and for individual positions. RESULTS: Total distances for the forwards and backs were 5731.1±507.8 and 6392.1±646.8 m, respectively. The high-velocity running distances (>18.0 km/hour) covered by the forwards and backs were 317.4±136.9 and 715.0±242.9 m, respectively. The number of accelerations (>1.5 m/s2) for the forwards and backs were 76.3±18.9 and 100.8±19.6 times, respectively, and the number of high impacts (>10 g) were 48.0±46.9 and 35.6±28.3 times for the forwards and backs, respectively. All characteristics were significantly different between the forwards and backs (p<0.05). The per-position characteristics were also calculated. Within the backs, scrum half (SH) and wingers (WTBs) covered high-velocity running significantly higher distance than fly-half (SH d=2.571, WTBs d=1.556) and centres (SH d=1.299, WTBs d=0.685) (p<0.05). CONCLUSION: By clarifying the physical demands according to the positions, it will be possible to create optimised position-specific training programmes.

Differences between the physiologic and psychologic effects of aromatherapy body treatment.

BACKGROUND: The wide use of herbal plants and essential oils for the prevention and treatment of diseases dates back to ancient times. However, the scientific basis for the beneficial effects of such plants and oils has not been precisely clarified. OBJECTIVE: The purpose of this study was to evaluate the effects of aromatherapy body treatment on healthy subjects. DESIGN: We compared the physiologic and psychologic effects of aromatherapy body treatment (E), massage treatment with carrier oil alone (C), and rest in healthy adults. SUBJECTS: Seven (7) female and 6 male volunteers participated as subjects. INTERVENTIONS: Each subject underwent 3 trials, in which the Advanced Trail Making Test (ATMT) was given as a stress-inducing task before and after 1 of 3 treatments. OUTCOME MEASURES: The State Anxiety Inventory (SAI), the Visual Analog Scale, and the Face Scale were used to assess anxiety, feelings, and mood, respectively. RESULTS: After the treatments, the SAI score and the feelings of fatigue were decreased, the positive and comfortable feelings were increased, and mood improved significantly in C and E. Furthermore, significant declines in the feelings of mental and total fatigue were maintained even after the second ATMT in E. On the other hand, the cortisol concentration in the saliva did not show significant changes in any of the trials. Secretory immunoglobulin A levels in the saliva increased significantly after all treatments. CONCLUSIONS: We conclude that massage treatments, irrespective of the presence of essential oils, are more advantageous than rest in terms of psychologic or subjective evaluations but not in terms of physiologic or objective evaluations. Furthermore, as compared to massage alone, the aromatherapy body treatment provides a stronger and continuous relief from fatigue, especially fatigue of mental origin.

The comparison between cool and warm-hot environments on lipolytic response during prolonged exercise.

The purpose of this study was to investigate the effect of cool exposure on lipolytic response during prolonged intermediate-intensity exercise in humans. Eight male subjects participated in this study; they performed 120-min cycle ergometer exercise at 60% of maximal oxygen uptake (VO2max) in a climatic chamber at 10 degrees C (C) and 30 degrees C (WH). There were no significant differences in oxygen uptake and respiratory exchange ratio between the two conditions during the prolonged exercise. Significant influences of cool exposure were observed in the changes in both heart rate and rectal temperature (p<0.01). Although cool exposure had no significant effects on plasma triglyceride, free fatty acid, and glycerol levels, changes in adrenaline and noradrenaline levels at C were significantly lower than WH during the prolonged exercise (p<0.01). Changes in the ratio of glycerol to noradrenaline (Gly/Nad), as an index of lipolytic efficiency, were significantly high at C as compared with WH (p<0.01). These results suggest that cool exposure has an influence on lipid metabolism during prolonged intermediate-intensity exercise, from the viewpoint of efficiency in lipolysis.

Plasma leptin levels of elite endurance runners after heavy endurance training.

A decrease in testosterone levels and an increase in cortisol levels are observed in male athletes with the overtraining syndrome (OTS). Cortisol causes blood leptin levels to rise and testosterone has an inverse relationship with blood leptin levels. Therefore, we hypothesized that the hormonal changes as a result of OTS induce an increase in leptin. To test this hypothesis, we examined the relationship among changes in leptin, testosterone and cortisol in thirteen male collegiate distance runners (aged 20.3+/-1.1 years) before and after an 8-day strenuous training camp. Runners ran 284.1+/-48.2 km during the training camp. Body fat percentages and plasma glucose concentrations decreased significantly after the training. Non-ester fatty acids and total cholesterol concentrations in blood were unchanged. Serum cortisol concentrations showed a significant increase after the training camp (from 11.82+/-2.00 microg/dl to 16.78+/-3.99 microg/dl), and serum testosterone decreased significantly (from 408.0+/-127.6 ng/dl to 265.2+/-97.6 ng/dl). The ratio of testosterone to cortisol (TCR) dropped by 50% after training (from 35.62+/-13.69 to 16.94+/-8.47). These results suggest that the subjects reached a state of the OTS. Contrary to our hypothesis, plasma leptin was not significantly changed (from 1.34+/-0.29 ng/ml to 1.49+/-0.18 ng/ml). Delta Plasma leptin was not significantly correlated with delta serum cortisol, delta TCR or delta fat percentage. However, delta serum testosterone was positively correlated with delta plasma leptin (r=596, p<0.05). Plasma leptin concentrations might modulate the secretion of testosterone in overtraining conditions. In conclusion, the change in blood leptin level is independent of the changes in cortisol, TCR and fat percentage in highly trained male athletes in the state of the OTS.