Auckland University of Technology

About: Auckland University of Technology is a education organization based out in Auckland, New Zealand. It is known for research contribution in the topics: Population & Context (language use). The organization has 4116 authors who have published 13461 publications receiving 353076 citations. The organization is also known as: AUT & AUT University.

The effect of recovery strategies on physical performance and cumulative fatigue in competitive basketball

Abstract: To evaluate the effectiveness of recovery strategies on physical performance during a 3-day tournament style basketball competition, 29 male players (mean age 19.1 years, s = 2.1; height 1.84 m, s = 0.34; body mass 88.5 kg, s = 14.7) were assigned to one of three treatment groups: carbohydrate + stretching (7.7 g · kg −1 · day −1, s = 1.7; ‘n = 9), cold water immersion (11°C, 5 × 1; n = 10) or full leg compression garments (18 mmHg, ∼18 h; n = 10). Effects of the recovery strategies on pre–post tournament performance tests were expressed as the mean change (% ± standard deviation of the change score). Changes and differences were standardized for accumulated game time, assessed against the smallest worthwhile change for each test, and reported qualitatively. Accumulated fatigue was evident over the tournament with small to moderate impairments in performance tests. Sprint and agility performance decreased by 0.7% (s = 1.3) and 2.0% (s = 1.9) respectively. Vertical jump decreased substantially aft...

Interactive Processes Link the Multiple Symptoms of Fatigue in Sport Competition

Abstract: Muscle physiologists often describe fatigue simply as a decline of muscle force and infer this causes an athlete to slow down. In contrast, exercise scientists describe fatigue during sport competition more holistically as an exercise-induced impairment of performance. The aim of this review is to reconcile the different views by evaluating the many performance symptoms/measures and mechanisms of fatigue. We describe how fatigue is assessed with muscle, exercise or competition performance measures. Muscle performance (single muscle test measures) declines due to peripheral fatigue (reduced muscle cell force) and/or central fatigue (reduced motor drive from the CNS). Peak muscle force seldom falls by >30% during sport but is often exacerbated during electrical stimulation and laboratory exercise tasks. Exercise performance (whole-body exercise test measures) reveals impaired physical/technical abilities and subjective fatigue sensations. Exercise intensity is initially sustained by recruitment of new motor units and help from synergistic muscles before it declines. Technique/motor skill execution deviates as exercise proceeds to maintain outcomes before they deteriorate, e.g. reduced accuracy or velocity. The sensation of fatigue incorporates an elevated rating of perceived exertion (RPE) during submaximal tasks, due to a combination of peripheral and higher CNS inputs. Competition performance (sport symptoms) is affected more by decision-making and psychological aspects, since there are opponents and a greater importance on the result. Laboratory based decision making is generally faster or unimpaired. Motivation, self-efficacy and anxiety can change during exercise to modify RPE and, hence, alter physical performance. Symptoms of fatigue during racing, team-game or racquet sports are largely anecdotal, but sometimes assessed with time-motion analysis. Fatigue during brief all-out racing is described biomechanically as a decline of peak velocity, along with altered kinematic components. Longer sport events involve pacing strategies, central and peripheral fatigue contributions and elevated RPE. During match play, the work rate can decline late in a match (or tournament) and/or transiently after intense exercise bursts. Repeated sprint ability, agility and leg strength become slightly impaired. Technique outcomes, such as velocity and accuracy for throwing, passing, hitting and kicking, can deteriorate. Physical and subjective changes are both less severe in real rather than simulated sport activities. Little objective evidence exists to support exercise-induced mental lapses during sport. A model depicting mind-body interactions during sport competition shows that the RPE centre-motor cortex-working muscle sequence drives overall performance levels and, hence, fatigue symptoms. The sporting outputs from this sequence can be modulated by interactions with muscle afferent and circulatory feedback, psychological and decision-making inputs. Importantly, compensatory processes exist at many levels to protect against performance decrements. Small changes of putative fatigue factors can also be protective. We show that individual fatigue factors including diminished carbohydrate availability, elevated serotonin, hypoxia, acidosis, hyperkalaemia, hyperthermia, dehydration and reactive oxygen species, each contribute to several fatigue symptoms. Thus, multiple symptoms of fatigue can occur simultaneously and the underlying mechanisms overlap and interact. Based on this understanding, we reinforce the proposal that fatigue is best described globally as an exercise-induced decline of performance as this is inclusive of all viewpoints.

Multiple effects of caffeine on simulated high-intensity team-sport performance

Abstract: Introduction: Caffeine enhances performance of single bouts of endurance exercise, but its effects on repeated bouts typical of those in high-intensity team sports are unclear. Purpose: To investigate effects of caffeine in a performance test simulating physical and skill demands of a rugby union game. Methods: The study was a double-blind, randomized, crossover design in which nine competitive male rugby players ingested either caffeine (6 mg[middle dot]kg-1 body mass) or placebo (dextrose) 70 min before performing a rugby test. Each test consisted of seven circuits in each of two 40-min halves with a 10-min half-time rest. Each circuit included stations for measurement of sprint time (two straight-line and three agility sprints), power generation in two consecutive drives, and accuracy for passing balls rapidly. Interstitial fluid was sampled transdermally by electrosonophoresis before ingestion of caffeine or placebo and then before testing, at half-time, and immediately after testing; samples were assayed chromatographically for caffeine and epinephrine concentrations. Results: The effects of caffeine on mean performance (+/-90% confidence limits) over all 14 circuits were: sprint speeds, 0.5% (+/-1.7%) through 2.9% (+/-1.3%); first-drive power, 5.0% (+/-2.5%); second-drive power, -1.2% (+/-6.8%); and passing accuracy, 9.6% (+/-6.1%). The enhancements were mediated partly through a reduction of fatigue that developed throughout the test and partly by enhanced performance for some measures from the first circuit. Caffeine produced a 51% (+/-11%) increase in mean epinephrine concentration; correlations between individual changes in epinephrine concentration and changes in performance were mostly unclear, but there were some strong positive correlations with sprint speeds and a strong negative correlation with passing accuracy. Conclusion: Caffeine is likely to produce substantial enhancement of several aspects of high-intensity team-sport performance.

Factors that affect software systems development project outcomes: A survey of research

Abstract: Determining the factors that have an influence on software systems development and deployment project outcomes has been the focus of extensive and ongoing research for more than 30 years. We provide here a survey of the research literature that has addressed this topic in the period 1996–2006, with a particular focus on empirical analyses. On the basis of this survey we present a new classification framework that represents an abstracted and synthesized view of the types of factors that have been asserted as influencing project outcomes.