The effect of induced alkalosis and submaximal cycling on neuromuscular response during sustained isometric contraction

Abstract

The aim of this study was to determine if inducing metabolic alkalosis would alter neuromuscular control after 50 min of standardized submaximal cycling. Eight trained male cyclists (mean age 32 years, s = 7; [Vdot]O_2max 62 ml · kg^?1 · min^?1, s = 8) ingested capsules containing either CaCO₃ (placebo) or NaHCO₃ (0.3 g · kg^?1 body mass) in eight doses over 2 h on two separate occasions, commencing 3 h before exercise. Participants performed three maximal isometric voluntary contractions (MVC) of the knee extensors while determining the central activation ratio by superimposing electrical stimulation both pre-ingestion and post-exercise, followed by a 50-s sustained maximal contraction in which force, EMG amplitude, and muscle fibre conduction velocity were assessed. Plasma pH, blood base excess, and plasma HCO₃ were higher (P < 0.01) during the NaHCO₃ trial. After cycling, muscle fibre conduction velocity was higher (P < 0.05) during the 50-s sustained maximal contraction with NaHCO₃ than with placebo (5.1 m · s^?1, s = 0.4 vs. 4.2 m · s^?1, s = 0.4) while the EMG amplitude remained the same. Force decline rate was less (P < 0.05) during alkalosis-sustained maximal contraction and no differences were shown in central activation ratio. These data indicate that induced metabolic alkalosis can increase muscle fibre conduction velocity following prolonged submaximal cycling.     

Home advantage in southern hemisphere rugby union: Nationaland international

Abstract

This study evaluates home advantages both for national (Super 12) and international (Tri-nations) rugby union teams from South Africa, Australia and New Zealand, over the five-year period 2000 – 2004 using linear modelling. These home advantages are examined for statistical and practical significance, for variability between teams, for stability over time and for inter-correlation. These data reveal that the overall home advantage in elite rugby union has a mean of +6.7 points, and that this changes little from year to year. Closer scrutiny nevertheless reveals a high degree of variability. Different teams can and do have different home advantages, which ranges from a low of ?0.7 to a high of +28.3 points in any one year. Furthermore, some team home advantages change up or down from one year to the next, by as much as ?36.5 to +31.4 points at the extremes. There is no evidence that the stronger teams have the higher home advantages, or that a high home advantage leads to a superior finishing position in the competition.     

Sand training: a review of current research and practical applications

Abstract

Sand surfaces can offer a higher energy cost (EC) and lower impact training stimulus compared with firmer and more traditional team sport training venues such as grass. This review aims to summarise the existing research on sand training, with a specific focus on its application as a team sports training venue. Compared with grass, significant physiological and biomechanical differences are associated with sand exercise. However, evidence also exists to suggest that training adaptations unique to sand can positively influence firm-ground performance. Furthermore, the lower impact forces experienced on sand can limit muscle damage, muscle soreness, and decrements in performance capacity relative to exercise intensity. Therefore, using a sand training surface in team sports may allow greater training adaptations to be achieved, while reducing performance decrements and injuries that may arise from heavy training. Nevertheless, further research should investigate the effect of sand surfaces over a greater range of training types and performance outcomes, to increase the application of sand training for team sports.     

Effects of Various Training Programs on Speed of Swimming

Abstract

Six groups of subjects were tested to determine if various training programs affected performance in speed in swimming 30 yards. No evidence of improvement was found after one group of subjects had been exposed to absolutely no exercise for six weeks and, also, after a group of subjects had participated in various exercises with weights three times weekly for six weeks. Two groups of swimmers who participated in practicing starts, kicking, arm stroking, and sprinting 30 and 60 yards significantly improved their performances in speed in swimming; one group of subjects followed the preceding program three times weekly and another group used the same routine six times a week. Two other groups, one of which was exposed to weight training and swimming, and one of which was exposed only to 30-yard sprints and practicing starts, both showed statistically significant differences in performance.     

Helping parents to become partners in the education of their handicapped child

Conclusions Educators are beginning to seek methods of improving parent-child relationships and school and parent relationships, as the evidence accrues and is assimilated, which shows how much more important is the child's family experience. The handicapped child brings the desirability of successful home and school links into clear focus, as the six-hour school day is clearly inadequate for the needs of many severely handicapped children, who require a consistent programme of developmental experiences from waking to sleeping. The only way in which the trust and confidence imposed by close relationships in the home may be continued in the school is by a mutual effort directed at common goals: the development of the child's capacity to learn and care for himself. Perhaps it is the similarity of the tasks undertaken in home and in school, with the severely and profoundly handicapped child, the severely and profoundly handicapped child, which has shown just how powerful the home-and-school combination can be when working in harmony. There are clearly lessons here for the education system at large. Perhaps the longstanding schism between parents and schools can be bridged in the next decades.The importance of social abilities, self-help skills and the confidence which all emanate from a successful family life, are emphasized by Smith and Sykes (1981) and others, who show that social competency is perhaps the key factor in determining vocational and post-school success for handicapped students. These competencies and confidence cannot come from school alone. The initiatives alluded to in this article, and described in full in the literature cited, show that schools have come a long way from believing that they alone can cope.Has written a number of studies on the development of education for the visually handicapped.