Keiko Miyahara

Physiological Responses of Simulated Karate Sparring Matches in young Men and Boys

The purpose of this study was to investigate the duration of each series of offensive and defensive techniques and the cardiovascular, metabolic, and perceptual responses during 2- and 3-minute bouts of simulated karate sparring. Six young men (age, 18-20 years) and 6 boys (age, 16-17 years) participated in this study. We formed 3 pairs of men and 3 pairs of boys to create a demanding competitive environment. After a rest period, each pair performed a 2-minute bout of sparring, sat quietly for 60 minutes, and then performed 3-minute bout of sparring. We measured oxygen uptake (&OV0312;o2), heart rate (HR), and blood lactate responses and ascertained the rate of perceived exertion (RPE) and energy expenditure (EE) during these sparring bouts. The ventilatory threshold was estimated from ventilatory equivalent and &OV0312;o2 obtained during the treadmill test. The duration of each series of offensive and defensive techniques was videotaped. During the 2- and 3-minute bouts of sparring, the duration of longest series of offensive and/or defensive combination techniques performed were 2.1 ± 1.0 and 1.8 ± 0.4 seconds, respectively; the mean total times of performing offensive and defensive techniques were 13.3 ± 3.3 and 19.4 ± 5.5 seconds, respectively. The mean oxygen uptake (&OV0312;o2), the percentage of maximum oxygen uptake (%&OV0312;o2max), HR, percentage of maximum HR, RPE, and EE for a 3-minute bout of sparring were significantly higher than for a 2-minute bout of sparring. The mean %&OV0312;o2max values for these bouts of sparring were below the ventilatory threshold. It is recommended that karate practitioners perform more specific weight training, plyometric exercises, and interval training to increase the ability to buffer acid muscle and blood concentrations and to build lean body mass, strength, and power to develop the specific motor skills required in sparring.

Nutrient intake, serum lipids and iron status of colligiate rugby players

BackgroundThere are two main playing positions in rugby (backs and forwards), which demonstrate different exercise patterns, roles, and physical characteristics. The purpose of this study was: 1) to collect baseline data on nutrient intake in order to advise the athletes about nutrition practices that might enhance performance, and 2) to compare serum lipids, lipoproteins, apolipoproteins (apo), lecithin:cholesterol acyltransferase (LCAT) activity, and iron status of forwards and backs.MethodsThe sporting group was divided into 18 forwards and 16 backs and were compared with 26 sedentary controls. Dietary information was obtained with a food frequency questionnaire.ResultsThere were significant differences among the three groups. The forwards had the highest body weight, body mass index, percentage of body fat (calculated by sum of four skinfold thicknesses), as well as the highest lean body mass, followed by the backs and the control group. The mean carbohydrate intake was marginal and protein intake was lower than the respective recommended targets in all three groups. The mean intakes of calcium, magnesium, and vitamins A, B1, B2, and C were lower than the respective Japanese recommended dietary allowances or adequate dietary intakes for the rugby players. The forwards had significantly lower high-density lipoprotein cholesterol (HDL-C) and HDL2-C than the backs and had significantly higher apo B and LCAT activity than the controls. The backs showed significantly higher HDL-C, HDL3-C, low-density lipoprotein cholesterol, and apo A-I, and LCAT activity than the controls. Four forwards (22%), five backs (31%), and three controls (12%) had hemolysis. None of the rugby players had anemia or iron depletion.ConclusionThe findings of our study indicate that as the athletes increased their carbohydrate and protein intake, their performance and lean body mass increased. Further, to increase mineral and vitamin intakes, we recommended athletes increase their consumption of green and other vegetables, milk and dairy products, and fruits. The forwards showed more atherogenic lipid profiles than the backs, whereas the backs showed not only anti-atherogenic lipid profile, but also showed more atherogenic lipid profile relative to the control group. Additionally, our study showed none of the rugby players experienced anemia and/or iron depletion.

Physical activity, high-density lipoprotein cholesterol subfractions and lecithin:cholesterol acyltransferase in dialysis patients.

Background/Aims: Although a low level of high-density lipoprotein cholesterol (HDL-C) is an independent risk factor for atherosclerotic heart disease, the mechanism of HDL-C abnormality in hemodialysis (HD) as well as peritoneal dialysis (PD) patients is not fully understood. The purpose of this study was to investigate the relationship of physical activity with HDL-C subfractions and lecithin:cholesterol acyltransferase activity in HD and PD patients. Methods: Thirty-five HD and 26 PD patients were studied. Physical activity was estimated as the average number of steps taken per day over 7 days (steps/day). Results: When possible confounding factors were included in the stepwise multiple regression analyses, in HD patients, steps/day was significantly positively related to HDL2-C and apolipoprotein (Apo) A-I, while it was significantly positively related to HDL3-C in PD patients. When subjects were subdivided into 3 groups according to steps/day, in HD patients, the highest category of steps/day had significantly higher HDL2-C and Apo A-I than the lowest category, while such results were not observed in PD patients. Conclusion: These results suggest that the associations of physical activity with HDL-C subfractions and Apo A-I that are known in the general population are more pronounced in HD patients than PD patients.

High-density lipoprotein cholesterol subfractions and lecithin: cholesterol acyltransferase activity in collegiate soccer players.

Many of the published data on the lipid profile of athletes is based on studies of endurance athletes. The data on soccer players are rare. The purpose of this study was to examine serum high-density lipoprotein cholesterol subfractions and lecithin:cholesterol acyltransferase activity in collegiate soccer players. 31 well-trained male collegiate soccer players were divided into 2 groups: 16 defenders and 15 offenders. They were compared with 16 sedentary controls. Dietary information was obtained with a food frequency questionnaire. The subjects were all non-smokers and were not taking any drug known to affect the lipid and lipoprotein metabolism. The offenders had significantly higher high-density lipoprotein cholesterol, high-density lipoprotein2 cholesterol, and apolipoprotein A-I than the defenders and controls, whereas the defenders had the significantly higher high-density lipoprotein2 cholesterol than the controls. Both groups of athletes had significantly higher lecithin:cholesterol acyltransferase activity than the controls. The results indicate that favorable lipid and lipoprotein profile could be obtained by vigorous soccer training.

Comparison of Nutrient Intake between Japanese Female Elite and Collegiate Karate Players

Most published data on the physical and physiological profiles of karate athletes is based on studies of male athletes and data on female athletes is rare. The purposes of this study were: 1) to collect baseline data on nutrient intake in order to advise athletes regarding nutrition practices that may enhance performance, and 2) to compare nutrient intake of elite and collegiate karate athletes. Thirtyfive female black belt karate athletes volunteered to participate in this study. They were divided into 2 groups: 20 athletes who were members of the national team (elite athletes) and 15 collegiate karate athletes (collegiate athletes). The elite athletes showed significantly higher mean lean body mass and significantly lower body fat and fat mass than the collegiate athletes. The elite athletes showed significantly higher energy intake and more nutrient intakes than the collegiate athletes. There were no significant differences in diet compositions between the elite and collegiate athletes. The elite athletes showed all micronutrient intakes were above 100% of the Estimated Average Requirement (EAR) or Adequate Intake (AIs), whereas the collegiate athletes showed micronutrient intakes below 100% of the EAR or AIs for potassium, calcium, magnesium, phosphorus, iron, vitamins A and C. Thus, we advised collegiate athletes to consume adequate amounts of carbohydrates and protein. To attain these goals, it is desirable to increase the amount of meals by increasing the intake levels of grains, vegetables, fruit, milk and dairy products, lean meat and fish.

High-Density Lipoprotein Cholesterol Subfractions in Collegiate Female Volleyball Players

Much of the published data on the lipid profiles of athletes are based on studies of endurance athletes. Data on female volleyball players are rare. The purpose of this study was thus to examine serum high-density-lipoprotein cholesterol (HDL-C) subfractions in collegiate female volleyball players. Twenty-six female collegiate volleyball players were compared with 26 age- and body mass index-matched control subjects. Dietary information was obtained with a food frequency questionnaire. The subjects were all nonsmokers and were not taking any drug known to affect lipid and lipoprotein metabolism. The volleyball players showed significantly higher mean HDL2-C than the control group. There were no significant differences in HDL-C and HDL3-C between the 2 groups. The results indicate that favorable lipid and lipoprotein profiles could be obtained by vigorous volleyball training and significantly higher HDL2-C could be obtained without observing significant differences in HDL-C and HDL3-C.

Calcaneal Bone Status in Elite Karate Practitioners

Karate is one of the most popular martial arts practiced both inside and outside of Japan. Traditional karate training consists of the practice of basic techniques, kata and sparring. The basic techniques such as punching, kicking, blocking and striking are practiced either in the stationary position or with body movements in various formal stances. Kata are set forms in a pre-established sequence of defensive and offensive techniques and movements. Sparring is the execution of defensive and offensive techniques while one is freely moving against an opponent. In addition to the traditional karate training, many competitive practitioners cross train by undertaking strenuous running and weight training programs to increase endurance, muscle development and power.