Richard Hugh Morton

• MA (Cambridge), PhD (Massey)
• Professor at Massey University

In spite of the Système International d'Unitès (SI) that was published in 1960, there continues to be widespread misuse of the terms and nomenclature of mechanics in descriptions of exercise performance. Misuse applies principally to failure to distinguish between mass and weight, velocity and speed, and especially the terms "work" and "power." The...

The purpose of this study was therefore to examine the published results from two recent elite classic powerlifting championship events in order to examine whether strategy, gender or location factors affect the relative frequencies of success or failure at such events; and whether, when considering each sequence of three attempts at a given liftin...

The purpose of this study was to assess the reliability of a 15-min time trial preloaded with 45 min of fixed-intensity cycling under laboratory conditions of thermal stress. Eight trained cyclists/triathletes (41 ± 10 years, VO2 peak: 69 ± 8 mL/kg/min, peak aerobic power: 391 ± 72 W) completed three trials (the first a familiarization) where they...

The purpose of this study is to investigate trends over time in critical speed, anaerobic distance capacity and maximal ‘instantaneous’ speed of male and female running record holders. At ten year intervals, a model of human bioenergetics is fitted to the then existing records at nine distances from 100m to the marathon, to provide estimates of the...

Introduction: Women increasingly occupy manual labor jobs. However, research examining women working under hot-humid conditions is lacking. Therefore, the purpose of our study was to assess how increasing relative humidity (RH) affects women's thermoregulation during low-intensity exercise characteristic of 8 h self-paced manual labor. Methods:...

The aim of this investigation was to determine and compare current and projected expenditure associated with chronic kidney disease (CKD), renal replacement therapy (RRT), and cardiovascular disease (CVD) in Australia. Data published by Australia and New Zealand Dialysis and Transplant Registry, Australian Institute of Health and Welfare, and World...

The purpose of this study was to determine whether improvements in endurance exercise performance elicited by strength training were accurately reflected by changes in parameters of the power-duration hyperbola for high-intensity exercise. Before and after 8 weeks of strength training (N=14) or no-exercise control (N=5), 19 males (age 20.6±2.0 year...

Histamine is a biogenic amine that forms in a variety of foods and can cause food poisoning at high concentrations (>500ppm). In situations where the formation of histamine in food cannot be prevented through refrigeration, diamine oxidase (DAO) enzyme may be used to degrade histamine to safe levels. The aims of this work were to apply DAO in model...

Abstract The "Critical Power" (CP) model of human bioenergetics provides a valuable way to identify both limits of tolerance to exercise and mechanisms that underpin that tolerance. It applies principally to cycling-based exercise, but with suitable adjustments for analogous units it can be applied to other exercise modalities; in particular to inc...

The study examined the maintenance of VO(2max) using VO(2max) as the controlling variable instead of power. Therefore, ten subjects performed three exhaustive cycling exercise bouts: (1) an incremental test to determine VO(2max) and the minimal power at VO(2max) (PVO(max)), (2) a constant-power test at PVO(max) and (3) a variable-power test (VPT) d...

This study was designed to determine whether V˙O(2) reaches a maximum, equivalent to that attained in an incremental exercise test to exhaustion, during "submaximal" fatigue-inducing constant-power exercise bouts above critical power (CP). Nine males (age = 24.6 ± 3.6 yr, height = 182.8 ± 6.9 cm, weight = 77.8 ± 12.1 kg) and four females (age = 29....

For any athlete competing at the highest level it is vital to understand the components that lead to successful performance. World cup cross-country mountain biking is a complex sport involving large numbers of athletes (100-200) competing for positional advantage over varied off-road terrain. The start has been deemed a major part of performance o...

This study tested the relevance of the critical power (CP) model for explaining exercise tolerance during intermittent high-intensity exercise with different recovery intensities. After estimation of CP and W' from a 3-min all-out test, seven male subjects completed, in randomized order, a cycle test to exhaustion at a severe-intensity constant-wor...

Histamine is a biogenic amine, which can cause food poisoning when present at high concentrations (>500 ppm). In situations where the formation of histamine in food cannot be prevented through traditional methods such as refrigeration, diamine oxidase (DAO) enzyme may be a suitable method to reduce histamine concentration to safe levels. The aim of...

This paper uses Bayesian methods via WinBUGS to model round robin play in the 2004 Super 12 Rugby Union competition in order to explore home advantage and how that impacts the outcome of the competition. The scores from the games are decomposed into counts of converted and unconverted tries, penalties and drop goals and are modelled as Poisson rand...

Poster

Experimental studies have consistently reported higher peak power outputs at the termination of steeper ramp exercises. One explanation can be deduced from oxygen uptake kinetics. This short communication offers an alternative explanation based on the "critical power" concept of human bioenergetics. Algebraic, calculus, and geometric aspects of thi...

Reports on reproducibility of lactate markers usually considered only two trials. The authors assessed reproducibility of power output at seven markers in 11 fit subjects over at least six trials under tightly controlled conditions. Subjects undertook incremental exercises (50 W start, +50 W every 3 min to exhaustion) on a cycle ergometer. At each...

Growth rate is an important factor in neonatal survival. The aim of this study was to determine growth rates in hand-reared cheetah cubs in South Africa fed a prescribed energy intake, calculated for growth in the domestic cat. Growth was then compared with previously published data from hand-reared cubs in North America and the relationship betwee...

The study examined whether or not acute exposure to unfamiliar hot or cold conditions impairs performance of highly skilled coordinative activities and whether prior physical self-efficacy beliefs were associated with task completion. Nineteen volunteers completed both Guitar Hero® and Archery® activities as a test battery using the Nintendo Wii® c...

For high-intensity muscular exercise, the time-to-exhaustion (t) increases as a predictable and hyperbolic function of decreasing power (P) or velocity (V). This relationship is highly conserved across diverse species and different modes of exercise and is well described by two parameters: the 'critical power' (CP or CV), which is the asymptote for...

This study evaluated exercise modality [i.e. self-paced (SP) or fixed-intensity (FI) exercise] as a modulator of body temperature regulation under uncompensable heat stress. Eight well-trained male cyclists completed (work-matched) FI and SP cycling exercise bouts in a hot (40.6 ± 0.2°C) and dry (relative humidity 23 ± 3%) environment estimated to...

Poor nutrient intake during pregnancy can adversely affect both infant and maternal health. The aim was to investigate the efficacy of multiple-micronutrient supplementation during pregnancy in a socially deprived population in the developed world. We conducted a randomised, double-blind, placebo-controlled trial of multiple-micronutrient supplemen...

P>The formation of SCFA and the digestion of rice fibre using the following probiotics (Lactobacillus rhamnosus, Lactobacillus acidophilus, Bifidobacterium longum, Bifidobacterium breve) was compared using total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) from two varieties (milling grades) of rice. The millin...

For high-intensity muscular exercise, the time-to-exhaustion (t) increases as a predictable and hyperbolic function of decreasing power (P) or velocity (V ). This relationship is highly conserved across diverse species and different modes of exercise and is well described by two parameters: the "critical power" (CP or CV), which is the asymptote fo...

Home advantage was evaluated using data from three national netball competitions: The Commonwealth Bank Trophy which ran from 1997 to 2007 in Australia, The National Bank Cup which ran from 1998 to 2007 in New Zealand, and The Co-operative Netball Superleague which ran from 2005/06 to 2008/09 in England. Mixed models were used to analyze the goal a...

Full-text of this article is not available in this e-prints service. This article was originally published following peer-review in International Journal of Food Science and Technology, published by and copyright Wiley-Blackwell Publishing Ltd. The formation of SCFA and the digestion of rice fibre using the following probiotics (Lactobacillus rhamn...

An isoperformance curve (or surface) defines combinations of two (or more) physiological attributes of individuals such that equal performances for a specified event would be expected of them. Parameters from the two- and three-parameter critical power models are used to illustrate the concept. There are a number of sporting races where teams of in...

The tolerable duration (t) of high-intensity cycle ergometry is well characterized by a hyperbolic function of power output (P) with an asymptote (termed the critical power (CP)) and a curvature constant (denoted W). The purpose of this study was to investigate the effect of prior heavy exercise (W-up) that specifically engenders an acidosis on CP...

Formation of biofilms in dairy membrane plants causes membrane pore blocking, product contamination and subsequent economic loss. To investigate the biofilm growth, two Klebsiella oxytoca strains, K. B006 and TR002, previously isolated from New Zealand dairy membrane plants, were grown both individually and combined on three types of ultrafiltratio...

This study examined the hypothesis that running speed over 800- and 1,500-m races is regulated by the prevailing anaerobic (oxygen independent) store (ANS) at each instant of the race up until the all-out phase of the race over the last several meters. Therefore, we hypothesized that the anaerobic power that allows running above the speed at maxima...

Protein is often considered the most satiating macronutrient. The objective was to determine the short-term effect of mixtures of whey protein and glycomacropeptide (GMP) versus a carbohydrate control on satiety in healthy adult humans. The study was a randomised crossover Latin Square design. On 4 separate days, fifty healthy subjects (19 males an...

The tolerable duration of high-intensity exercise can be described by a simple hyperbolic function of power or velocity, with an asymptote referred to as the 'critical power/velocity' and a curvature constant referred to as the 'anaerobic work/distance capacity'. More recently, this hyperbola has been generalized by permitting a non-zero temporal a...

It is common for athletes striving to achieve maximal effort to exercise in the presence of a visible clock. It is implicitly assumed that calibration of the clock is normal (i.e. accurate). This study was designed to test the effect of secretly manipulating the clock calibration on maximal effort as measured by endurance times in cycle ergometry....

The purpose of this study was to examine season-to-season variations in physiological fitness parameters among a 1st team squad of professional adult male soccer players for the confirmatory purposes of identifying normative responses (immediately prior to pre-season training (PPS), mid-season (MID), and end-of-season (EOS)). Test-retest data were...

Felinine is a branched-chain sulfur amino acid present in the urine of certain Felidae, including domestic cats. The objective of the present study was to determine if additional cystine and/or dietary N would increase felinine and N-acetylfelinine excretion by intact male cats fed a low-protein(LP) diet. Feeding five adult intact male cats an LP d...

KAY, B.; STANNARD, S. R.; MORTON, R. H. Hyperoxia during recovery improvespeak power during repeated Wingate cycle performance. Brazilian Journal ofBiomotricity, v. 2, n. 2, p. 92-100, 2008. Purpose: We have used a random order singleblind crossover design to assess the effect of breathing 21% O2, 60% O2, and 100% O2during a four-minute recovery fr...

The effectiveness and optimality of whole body vibration (WBV) duration on muscular strength is yet to be determined. Hence the aim of this study was to investigate the effects of three different durations of continuous WBV exposure on isometric right knee extensor strength measured pre and post exposure. The study involved 12 trained male subjects...

The benefits of rapid recovery after intense exercise are widely recognised, and lactate elimination is one indicator of recovery rate. This study examined the effect of contrast (alternating hot and cold) water immersion (CWI) on the rate of plasma lactate decrease during recovery after intense anaerobic exercise. Eleven subjects on each of two oc...

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 ov...

This paper takes a performance-based approach to review the broad expanse of literature relating to whole-body models of human bioenergetics. It begins with an examination of the critical power model and its assumptions. Although remarkably robust, this model has a number of shortcomings. Attention to these has led to the development of more realis...

The relationships between both metabolic (E) and mechanical (W) energy expended and exhaustion time (t(e)), was determined for 11 well-trained subjects during constant load cycloergometric exercises at 95, 100, 110, 115 % maximal aerobic power performed both from rest and, without interruption, after an all-out sprint of 7 s. These relationships we...

Many researchers (e.g. Coffey et al., 2004) have indicated that recovery from acute exercise induced muscular fatigue could be expedited by increased rapidity of lactate (LA-) clearance from the blood. This argument is based on the following logical progression: Firstly, increased intra-myocellular LA- concentration has been proposed to exert vario...

The basic anatomy of an experimental design is used as an expository introduction to the examination of several repeated measures experiments described in recent pages of this and other journals. This examination reveals problematic issues concerning some common design and analysis features of such experimental designs. In particular, the hierarchi...

This paper develops and illustrates the critical power model for intermittent work. Model theoretic development reveals that total endurance time is always a step function of one or more of the four independent variables: work interval power output (P w), rest interval power output (P r), work interval duration (t w), and rest interval duration (t...

If the table of Olympic medals is ordered by total medals won, it is dominated by the larger wealthier nations. However, when ordered by medals per capita, small island nations dominate, and the eastern bloc dominates when ordering is on medals per gross domestic product. This situation changes only somewhat when medal `points' are considered (gold...

This study determined the amplitude and rate of adaptation to 10 wk of continuous (CEx) and intermittent exercise (IEx) in a group of older men when the training intensity and total amount of work completed by each exercise group were the same. Ten healthy men were assigned to either a CEx (63 +/- 1 yr) or IEx (65 +/- 1 yr) group while a further fi...

World record data are available for races run entirely in lanes. These are analysed for the effects of lane allocation manifested by curvature of the track, gender differences and the imposition of hurdles. Although males run significantly faster than females and hurdles slow runners down, there is little evidence that the less curved lanes can be...

There has been significant recent interest in the minimal running velocity which elicits VO2max. There also exists a maximal velocity, beyond which the subject becomes exhausted before VO2max is reached. Between these limits, there must be some velocity that permits maximum endurance at VO2max, and this parameter has also been of recent interest. T...

Introduction: There has been significant recent interest in the minimal running velocity which elicits (V) over dot (2max). There also exists a maximal velocity, beyond which the subject becomes exhausted before (V) over dot (2max) reached. Between these limits, there must be some velocity that permits maximum endurance at (V) over dot (2max), and...

The purpose of this study was to characterise the relationship between running velocity and the time for which a subject can run at maximal oxygen uptake (V˙O2max), (t limV˙O2max). Seven physical education students ran in an incremental test (3-min stages) to determine V˙O2max and the minimal velocity at which it was elicited (νV˙O2max). They then...

Traditionally, poplars (Populus) have been planted to control erosion on New Zealand’s hill-slopes, because of their capacity to dry out and bind together the soil, by reducing effective rainfall and increasing evapotranspiration and soil strength. However, the effect of widely spaced poplars on the partitioning of soil water and rainfall has not b...

Containerized plants of Heliconia psittacorum L.f. x H. spathocircinata Aristeguieta 'Golden Torch' were grown in a greenhouse for 8 months from early summer to winter under selected combinations of N, P, and K. Fertilizer rates ranged from zero to rates that exceeded those reported in the literature by 50% to 100%. Biomass variables (vegetative an...

This article traces the study of interrelationships between power output, work done, velocity maintained or distance covered and the endurance time taken to achieve that objective. During the first half of the twentieth century, scientists examined world running records for distances from < 100 m to > 1000 km. Such examinations were empirical in na...

This article traces the study of interrelationships between power output, work done, velocity maintained or distance covered and the endurance time taken to achieve that objective. During the first half of the twentieth century, scientists examined world running records for distances from <100m to >1000km. Such examinations were empirical in nature...

The aim of this study was to measure serial changes in the rate of blood lactate clearance (gamma2) in response to sequential periods of training and detraining in four male triathletes aged 22-44 years. There were two major phases of training and taper, each lasting 4-5 weeks (training 1 = 5 weeks, taper 1 = 2 weeks, training 2 = 4 weeks and taper...

This study investigated the effects of acute ingestion of caffeine (C), ephedrine (E) and their combination (C+E) on time to exhaustion during high-intensity exercise. Using a repeated-measures, double-blind design, eight male subjects exercised on a cycle ergometer at a power output that led to exhaustion after about 12.6 min during a placebo (P)...

This paper adapts the dose-response research tool, well established in pharmacological studies, to an exercise and performance setting. Training is measured in quantitative units as the dosage inputs, and their effects on fitness, fatigue, overtraining and performance responses are modelled. In this way, one can answer such questions as 'what perfo...

The standard critical power test protocol on the cycle ergometer prescribes a series of trials to exhaustion, each at a different but constant power setting. Recently the protocol has been modified and applied to a series of trials to exhaustion each at a different ramp incremental rate. This study was undertaken to compare critical power and anaer...

The critical power test provides estimates of two important parameters characterizing work performance; anaerobic work capacity (AWC) and critical power (CP). The CP concept has recently been adapted to a test procedure involving ramp exercise. Just as the constant power format of the CP test can be expressed in several mathematically equivalent fo...

The critical power test is a well-established procedure that provides estimates of two important parameters characterizing work performance; anaerobic work capacity (AWC) and critical power (CP). The concept proscribes a hyperbolic relationship between power output (P) and time to exhaustion (t), given by (P - CP)t = AWC. Since evidence now exists...

It is well established that for work requiring high power output, endurance time is short, and that low power outputs can be maintained for long periods. Parameters describing this relationship are important in characterising work performance and the capacity of humans as a source of mechanical power. The purpose of this paper is to provide a brief...

Stimuli used to probe the acute physical/physiological response to exercise are well known and characterised so that the pattern and size of their effect may be used diagnostically with some precision (21,22). There is no similar precision of thought on training. Although most training studies show the generally positive benefit of exercise, there...

Surface areas of fruits and vegetables are often estimated by assuming that they resemble a shape from which surface area can be mathematically calculated. Two such models, sphere and ellipsoid, were compared to three alternative approaches for estimating surface areas of apple fruit (Malus domestica Borkh.) of four cultivars ('Royal Gala’, ‘Braebu...

The critical power test for cycle ergometry has been criticised as providing an overestimate of the real value of the critical power. Part of the blame may rest in the practical problem associated with getting reliable measurements of longer endurance times when power settings are not much above the critical power. However, by adjusting the increme...

This study presents an elementary model of a system which relates plasma lactate concentration ([La−]) during ramp exercise to its rate of accumulation (R c) within its extramuscular distribution space (S). Under the parsimonious assumptions that R c increases linearly with time (t) with a kinetic delay (δ), and that the volume of S is constant, it...

A number of studies have identified the existence of two ventilation thresholds during ramp or incremental exercise to exhaustion on the cycle ergometer. This study was undertaken to investigate whether two threshold turnpoints could be identified in blood lactate concentration data collected at such times. Five trained athletes provided serial blo...

1. In this short review, previous studies regarding the modeling of lactate (La) response to exercise and its application to endurance training have been summarized. 2. Additionally the result of a recent study by the present authors are shown. 3. Several models for La response to step and ramp exercise are already proposed and deductions derived f...

A recent paper in this journal has examined the ventilatory compensation for metabolic acidosis with increasing oxygen uptake, making extensive use of mathematical and statistical techniques. The authors conclude that '...respiratory compensation for metabolic acidosis during incremental exercise is a continuous process...'. While this may indeed b...

The well-documented pattern of elevated serum enzyme activity (ESEA) data after a single bout of unaccustomed exercise can very easily be modeled using a biexponential curve. However, the changed pattern of ESEA after a second exercise bout, or after a period of conditioning or during repetitive training, demonstrates that exercise-induced adaptati...

This study has measured the pattern of elevated serum enzyme activity (ESEA) during extended daily training in a dose-response manner and compared ESEA to the pattern of accumulated fitness and fatigue predicted from a mathematical model previously described. Blood samples were taken regularly during the study from each subject and the activity of...

In this paper, previous studies regarding the effect of physical training on the disappearance rate of blood La during recovery after strenuous exercise have been briefly summarized. The results of our own recent study of this problem have also been added. It may be concluded that there is some evidence for an improved lactate metabolic clearance r...

Recent application of modeling techniques to physical training has opened the possibility for prediction from training. Solution of the inverse problem, determining a training program to produce a desired performance at a specific time, is also possible and may yield strategies for achieving better training and tapering (complete or relative rest f...

A systems model that quantifies the effects of training on athletic performance has been subjected to a detailed simulation study. Four performance‐related variables were considered: (1) predicted peak performance, (2) the date of its occurrence, (3) an index of overtraining stress, and (4) the robustness of predicted performances around the peak....

This paper focuses on the characteristics of a model interpreting the effect of training on athletic performance. The model theory is presented both mathematically and graphically. In the model, a systematically quantified impulse of training produces dual responses: fitness and fatigue. In the absence of training, both decay exponentially with tim...

A generalised three component hydraulic model has been proposed to represent the human bioenergetic processes relating internal energy stores to performance during exercise, and into recovery. Further development of the model allows testable predictions to be made. In particular in this paper I examine certain hypotheses of chemical fuel shortage a...

An important question in the study of the exercise response is the real or imaginary nature of the anaerobic threshold, and mathematical modeling techniques have been invoked to assist in resolving this issue. Two opposing views with competing data models recently published in this journal are criticized. One view suggests a segmented model with a...

After an unsatisfactory 1981 attempt at a computerized prediction system on election night, Television New Zealand went into the snap 1984 election with an untried new procedure. The promise of that system has borne fruit in the 1987 election. This article describes the statistical methodology of the system and some of the results obtained on elect...

Reported experimental findings are at variance with each other on the question as to whether O2 uptake (VO2) kinetics are delayed, advanced, or remain unaltered in the transition from prior exercise. Critical examination of these studies tend to suggest that not a great deal of reliance can be placed on their evidence in attempting to resolve the q...