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The purpose of the current article was to use allometric models to identify the best body size descriptors and other anthropometric variables, body composition, and offset maturity that might be associated with the youngsters' 50m personal-best (PB) swim speeds (m·s -1 ). Eighty-five competitive swimmers (male, n=50; 13.5±1.8 y; female, n=35; 12.6±1.8 y) participated in this study. Height, body mass, sitting height, arm span, skinfolds, arm muscle area (AMA), and maturity offset were assessed. Swimming performance was taken as the PB time recorded in competition, and the propulsive force of their arm (PFA) was assessed by the tied swimming test. The multiplicative allometric model relating 50m PB swim speeds (m·s -1 ) to all the predictor variables found percentage body fat as a negative [(BF%) β= -.121±.036;  P =0.001], and PFA (PFA β=.108±.033;  P =0.001) and the girl's arm span (β=.850±.301;  P =0.006), all log-transformed, as positive significant predictors of log-transformed swim speed. The adjusted coefficient of determination, R adj 2  was 54.8% with the log-transformed error ratio being 0.094 or 9.8%, having taken antilogs. The study revealed, using an allometric approach, that body fatness and PFA were significant contributors to 50m freestyle swim performance in young swimmers.

Background: Previous research into the association between aerobic fitness and physical activity in children is equivocal. However, previous research has always assumed that such an association was linear. This study sought to characterize the dose-response association between physical activity and aerobic fitness and to assess whether this association is linear or curvilinear and varies by sex, age and weight status., Methods: Physical activity (assess using the Physical Activity Questionnaire), aerobic fitness (20 m shuttle-run), BMI, screen-time and socio-demographic data were collected at ages 12, 14 and 16 years in (n = 1422) volunteers from 9 English schools. Multilevel-regression modelling was used to analyse the longitudinal data., Results: The analysis identified a significant inverted "u-shaped" association between VO 2 max and PAQ. This relationship remained having controlling for the influences of sex, age and weight status. Daily screen time >4 hours and deprivation were also associated with being less fit (P < 0.01)., Conclusions: This longitudinal study suggests that the dose-response relationship between PA and aerobic fitness in children is curvilinear. The health benefits of PA are greater in less active children and that sedentary and less active children should be encouraged to engage in PA rather than more active children to increase existing levels of PA.

This study identified key somatic and demographic characteristics that benefit all swimmers and, at the same time, identified further characteristics that benefit only specific swimming strokes. Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. We adopted a multiplicative, allometric regression model to identify the key characteristics associated with 100 m swimming speeds (controlling for age). The model was refined using backward elimination. Characteristics that benefited some but not all strokes were identified by introducing stroke-by-predictor variable interactions. The regression analysis revealed 7 "common" characteristics that benefited all swimmers suggesting that all swimmers benefit from having less body fat, broad shoulders and hips, a greater arm span (but shorter lower arms) and greater forearm girths with smaller relaxed arm girths. The 4 stroke-specific characteristics reveal that backstroke swimmers benefit from longer backs, a finding that can be likened to boats with longer hulls also travel faster through the water. Other stroke-by-predictor variable interactions (taken together) identified that butterfly swimmers are characterized by greater muscularity in the lower legs. These results highlight the importance of considering somatic and demographic characteristics of young swimmers for talent identification purposes (i.e., to ensure that swimmers realize their most appropriate strokes).

The purpose of this study was to estimate the optimal body size, limb-segment length, girth or breadth ratios for 100-m backstroke mean speed performance in young swimmers. Sixty-three young swimmers (boys [n = 30; age: 13.98 ± 0.58 years]; girls [n = 33; age: 13.02 ± 1.20 years]) participated in this study. To identify the optimal body size and body composition components associated with 100-m backstroke speed performance, we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. The multiplicative allometric model exploring the association between 100-m backstroke mean speed performance and the different somatic measurements estimated that biological age, sitting height, leg length for the lower-limbs, and two girths (forearm and arm relaxed girth) are the key predictors. Stature and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. In fact, it is only by adopting multiplicative allometric models that the abovementioned ratios could have been derived. These findings highlighted the importance of considering somatic characteristics of young backstroke swimmers and can help swimming coaches to classify their swimmers and enable them to suggest what might be the swimmers' most appropriate stroke (talent identification).

The aim of this current randomised controlled trial was to evaluate the effects of a home-based physical activity (PA) intervention on cardiorespiratory fitness in breast cancer survivors. Thirty-two post-adjuvant therapy breast cancer survivors (age = 52 ± 10 years; BMI = 27.2 ± 4.4 kg∙m 2 ) were randomised to a six-month home-based PA intervention with face-to-face and telephone PA counselling or usual care. Cardiorespiratory fitness and self-reported PA were assessed at baseline and at six-months. Participants had a mean relative V̇O 2 max of 25.3 ± 4.7 ml∙kg -1 ∙min -1 , which is categorised as "poor" according to age and gender matched normative values. Magnitude-based inference analyses revealed likely at least small beneficial effects (effect sizes ≥.20) on absolute and relative V̇O 2 max (d = .44 and .40, respectively), and total and moderate PA (d = .73 and .59, respectively) in the intervention compared to the usual care group. We found no likely beneficial improvements in any other outcome. Our home-based PA intervention led to likely beneficial, albeit modest, increases in cardiorespiratory fitness and self-reported PA in breast cancer survivors. This intervention has the potential for widespread implementation and adoption, which could considerably impact on post-treatment recovery in this population.

This study assessed whether decisions made by six qualified referees were consistent when watching the live 2016 televised Champions League Final. Referees were paired off into three separate rooms. Two referees watched the game with no supporters present. Two watched the game surrounded by Real Madrid supporters, and the remaining two watched the game surrounded by Athletic Madrid supporters. Referees were asked to decide whether each decision made by the on-field referee was either correct or incorrect. Results identified two types of refereeing inconsistency. The first type was a systematic tendency of the supporting crowds (both rooms) to influence the adjudicating referees to make fewer incorrect (disagree with the on-field referee) decisions (8 and 5) than referees in the "no supporters" room (19) (χ 2  = 11.22 [df = 2], P = 0.004). The second type of inconsistency was the home advantage "bias", where the surrounding crowd influenced the adjudicating referees to favour their team, by disagreeing with the decision made by the on-field referee (χ 2  = 6.0 [df = 2], P = 0.0498). One explanation for these inconsistencies is that referees adopt a coping strategy of "avoidance", i.e., when faced with difficult decisions, referees simply avoid making unpopular decisions by waving "play on".

An evaluation of a six-week Combined minimal footwear transition and gait-retraining combination vs. gait retraining only on impact characteristics and leg stiffness. Twenty-four trained male runners were randomly assigned to either (1) Minimalist footwear transition Combined with gait-retraining over a six-week period ("Combined" group; n = 12) examined in both footwear, or (2) a gait-retraining group only with no minimalist footwear exposure ("Control"; n = 12). Participants were assessed for loading rate, impact peak, vertical, knee and ankle stiffness, and foot-strike using 3D and kinetic analysis. Loading rate was significantly higher in the Combined group in minimal shoes in pre-tests compared to a Control (P ≤ 0.001), reduced significantly in the Combined group over time (P ≤ 0.001), and was not different to the Control group in post-tests (P = 0.16). The impact peak (P = 0.056) and ankle stiffness reduced in both groups (P = 0.006). Loading rate and vertical stiffness was higher in minimalist footwear than conventional running shoes both pre (P ≤ 0.001) and post (P = 0.046) the intervention. There has a higher tendency to non-rearfoot strike in both interventions, but more acute changes in the minimalist footwear. A Combined intervention can potentially reduce impact variables. However, higher loading rate initially in minimalist footwear may increase the risk of injury in this condition.

Body image is an important concept when assessing mental health and, thus, a target for intervention work. The common approach to assess body image is via self-report and, consequently, it is important to assess stability and susceptibility of items to random change. Participants (N = 99, aged: 18-30 years) completed the 34-item Multidimensional Body Self-Relations Questionnaire-Appearance Scales (MBSRQ-AS) twice, separated by two weeks. Stability was quantified by calculating the test-retest differences for each item, with a stable item showing 90% of respondents' differences within a criterion of ≤±1. This method was used in preference to correlation, which is a test of association rather than agreement. Analyses identified 29 stable items. Five items were found to be unstable including the entire "Appearance Evaluation" scale. One particular unstable question, Q9 = "Most people would consider me good-looking", revealed strong associations with both gender and weight status. Forty-four per cent of "overweight" respondents changed their minds by more than ±1 compared with only 10% of "normal-weight" participants, suggesting that being overweight is associated with uncertainty and instability. We suggest that future research is needed to investigate why such factors as being overweight appear to be linked to instability in self-report measures of body image.

Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis-thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r (2) = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = -0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies.

The aim of the present study was to identify when body mass index (BMI) is unlikely to be a valid measure of adiposity in athletic populations and to propose a simple adjustment that will allow the BMI of athletes to reflect the adiposity normally associated with non-athletic populations. Using data from three previously published studies containing 236 athletes from seven sports and 293 age-matched controls, the association between adiposity (sum of 4 skinfold thicknesses, in millimetres) and BMI was explored using correlation, linear regression, and analysis of covariance (ANCOVA). As anticipated, there were strong positive correlations (r = 0.83 for both men and women) and slope parameters between adiposity and BMI in age-matched controls from Study 1 (all P < 0.001). The standard of sport participation reduced these associations. Of the correlations and linear-regression slope parameters between adiposity and BMI in the sports from Studies 2 and 3, although still positive in most groups, less than half of the correlations and slope parameters were statistically significant. When data from the three studies were combined, the ANCOVA identified that the BMI slope parameter of controls (5.81 mm (kg m(-2))(-1)) was greater than the BMI slope parameter for sports (2.62 mm (kg m(-2))(-1)) and middle-distance runners (0.94 mm (kg m(-2))(-1)) (P < 0.001). Based on these contrasting associations, we calculated how the BMI of athletes can be adjusted to reflect the same adiposity associated with age-matched controls. This simple adjustment allows the BMI of athletes and non-athletes to be used with greater confidence when investigating the effect of BMI as a risk factor in epidemiological research.

The purpose of this study was to determine whether there is a causal relationship between pedalling "circularity" and cycling efficiency. Eleven trained cyclists were studied during submaximal cycling. Variables recorded included gross and delta efficiency and the ratio of minimum to peak torque during a duty cycle. Participants also completed a questionnaire about their training history. The most notable results were as follows: gross efficiency (r = -0.72, P < 0.05 at 250 W) was inversely correlated with the ratio of minimum to peak torque, particularly at higher work rates. There was a highly significant inverse correlation between delta efficiency and average minimum torque at 200 W (r = -0.76, P < 0.01). Cycling experience was positively correlated with delta efficiency and gross efficiency, although experience and the ratio of minimum to peak torque were not related. These results show that variations in pedalling technique may account for a large proportion of the variation in efficiency in trained cyclists. However, it is also possible that some underlying physiological factor influences both. Finally, it appears that experience positively influences efficiency, although the mechanism by which this occurs remains unclear.

The aims of this study were to compare the physiological demands of laboratory- and road-based time-trial cycling and to examine the importance of body position during laboratory cycling. Nine male competitive but non-elite cyclists completed two 40.23-km time-trials on an air-braked ergometer (Kingcycle) in the laboratory and one 40.23-km time-trial (RD) on a local road course. One laboratory time-trial was conducted in an aerodynamic position (AP), while the second was conducted in an upright position (UP). Mean performance speed was significantly higher during laboratory trials (UP and AP) compared with the RD trial (P < 0.001). Although there was no difference in power output between the RD and UP trials (P > 0.05), power output was significantly lower during the AP trial than during both the RD (P = 0.013) and UP trials (P = 0.003). Similar correlations were found between AP power output and RD power output (r = 0.85, P = 0.003) and between UP power output and RD power output (r = 0.87, P = 0.003). Despite a significantly lower power output in the laboratory AP condition, these results suggest that body position does not affect the ecological validity of laboratory-based time-trial cycling.

The existing literature suggests that crank inertial load has little effect on the responses of untrained cyclists. However, it would be useful to be aware of any possible effect in the trained population, particularly considering the many laboratory-based studies that are conducted using relatively low-inertia ergometers. Ten competitive cyclists (mean VO(2max) = 62.7 ml x kg(-1) x min(-1), s = 6.1) attended the human performance laboratories at the University of Wolverhampton. Each cyclist completed two 7-min trials, at two separate inertial loads, in a counterbalanced order. The inertial loads used were 94.2 kg x m(2) (high-inertia trial) and 2.4 kg x m(2) (low-inertia trial). Several physiological and biomechanical measures were undertaken. There were no differences between inertial loads for mean peak torque, mean minimum torque, oxygen uptake, blood lactate concentration or perceived exertion. Several measures showed intra-individual variability with blood lactate concentration and mean minimum torque, demonstrating coefficients of variation > 10%. However, the results presented here are mostly consistent with previous work in suggesting that crank inertial load has little direct effect on either physiology or propulsion biomechanics during steady-state cycling, at least when cadence is controlled.

Previous researchers have identified significant differences between laboratory and road cycling performances. To establish the ecological validity of laboratory time-trial cycling performances, the causes of such differences should be understood. Hence, the purpose of the present study was to quantify differences between laboratory- and road-based time-trial cycling and to establish to what extent body size [mass (m) and height (h)] may help to explain such differences. Twenty-three male competitive, but non-elite, cyclists completed two 25 mile time-trials, one in the laboratory using an air-braked ergometer (Kingcycle) and the other outdoors on a local road course over relatively flat terrain. Although laboratory speed was a reasonably strong predictor of road speed (R2 = 69.3%), a significant 4% difference (P < 0.001) in cycling speed was identified (laboratory vs. road speed: 40.4 +/- 3.02 vs. 38.7 +/- 3.55 km x h(-1); mean +/- s). When linear regression was used to predict these differences (Diff) in cycling speeds, the following equation was obtained: Diff (km x h(-1)) = 24.9 - 0.0969 x m - 10.7 x h, R2 = 52.1% and the standard deviation of residuals about the fitted regression line = 1.428 (km . h-1). The difference between road and laboratory cycling speeds (km x h(-1)) was found to be minimal for small individuals (mass = 65 kg and height = 1.738 m) but larger riders would appear to benefit from the fixed resistance in the laboratory compared with the progressively increasing drag due to increased body size that would be experienced in the field. This difference was found to be proportional to the cyclists' body surface area that we speculate might be associated with the cyclists' frontal surface area.

In this paper, we identify appropriate statistical methods for analysing categorical differences in discrete variables or 'performance indicators' resulting from performance analysis. The random mechanisms associated with discrete events do not follow a normal distribution; that is, the normal distribution is a continuous not a discrete probability distribution. We propose appropriate statistical methods based on two key discrete probability distributions, the Poisson and binomial distributions. Two approaches are proposed and compared using examples from notational analysis. The first approach is based on the classic chi-square test of significance (both the goodness-of-fit test and the test of independence). The second approach adopts a more contemporary method based on log-linear and logit models fitted using the statistical software GLIM. Provided relatively simple one-way and two-way comparisons in categorical data are required, both of these approaches result in very similar conclusions. However, as soon as more complex models or higher-order comparisons are required, the approach based on log-linear and logit models is shown to be more effective. Indeed, when investigating those factors and categorical differences associated with binomial or binary response variables, such as the proportion of winners when attempting decisive shots in squash or the proportion of goals scored from all shots in association football, logit models become the only realistic method available. By applying log-linear and logit models to discrete events resulting from notational analysis, greater insight into the underlying mechanisms associated with sport performance can be achieved.

The aim of this review is to discuss some issues in the design and statistical analysis of sport performance research, rather than to supply an authoritative 'cookbook' of methods. In general, we try to communicate some possible solutions to the conundrum of how to maintain both internal and external validity, as well as optimize statistical power, in applied sport performance research. We start by arguing that some sport performance research has been overly concerned with physiological predictors of performance, at the expense of not providing a valid and reliable description of the exact nature of the task in question. We show how the influence of certain factors on competitive performances can be described using linear or logistic regression. We discuss the choice of analysis for factorial repeated-measures designs, which is complicated by the assumption of 'sphericity' in a univariate general linear model, and the relatively low statistical power of the multivariate approach when used with small samples. We consider a little-used and simpler technique known as 'analysis of summary statistics'. In multi-group pre- and post-test designs, a useful technique can be to pair-match individuals on their performance scores in a counterbalanced fashion before the intervention or control has been introduced. Finally, we outline how confidence intervals can help in making statements about the probability of the population difference in performance exceeding the value designated as being worthwhile or not.

In 1999, Wilson and Batterham proposed a new approach to assessing the test-retest stability of psychometric questionnaires. They recommended assessing the proportion of agreement - that is, the proportion of participants that record the same response to an item - using a test-retest design. They went on to use a bootstrapping technique to estimate the uncertainty of the proportion of agreement. The aims of this short communication are (1) to demonstrate that the sampling distribution of the proportion of agreement is well known (the binomial distribution), making the technique of 'bootstrapping' redundant, and (2) to suggest a much simpler, more sensitive method of assessing the stability of a psychometric questionnaire, based on the test-retest differences (within-individuals) for each item. Adopting methods similar to Wilson and Batterham, 97 sport students completed the Social Physique Anxiety Scale on two occasions. Test-retest differences were calculated for each item. Our results show that the proportion of agreement ignores the nature of disagreement. Items 4 and 11 showed similar agreement (44.3% and 43.3% respectively), but 89 of the participants (91.8%) differed by just +/-1 point when responding to item 4, indicating a relatively stable item. In contrast, only 78 of the participants (80.4%) recorded a difference within +/- 1 point when responding to item 11, suggesting quite contrasting stability for the two items. We recommend that, when assessing the stability of self-report questionnaires using a 5-point scale, most participants (90%) should record test-retest differences within a reference value of +/- 1.

We obtained indices of home advantage, based on the medals won by competing nations, for each event held at the Winter Olympics from 1908 to 1998. These indices were designed to assess home advantage while controlling for nation strength, changes in the number of medals on offer and the performance of 'non-hosting' nations. Some evidence of home advantage was found in figure skating, freestyle skiing, ski jumping, alpine skiing and short track speed skating. In contrast, little or no home advantage was observed in ice hockey, Nordic combined, Nordic skiing, bobsled, luge, biathlon or speed skating. When all events were combined, a significant home advantage was observed (P = 0.029), although no significant differences in the extent of home advantage were found between events (P > 0.05). When events were grouped according to whether they were subjectively assessed by judges, significantly greater home advantage was observed in the subjectively assessed events (P = 0.037). This was a reflection of better home performances, suggesting that judges were scoring home competitors disproportionately higher than away competitors. Familiarity with local conditions was shown to have some effect, particularly in alpine skiing, although the bobsled and luge showed little or no advantage over other events. Regression analysis showed that the number of time zones and direction of travel produced no discernible trends or differences in performance.

Muscle strength is thought to be a major factor in athletic success. However, the relationship between muscle strength and sprint performance has received little attention. The aim of this study was to examine the relationship in elite performers of isokinetic muscle strength across three lower limb joints and sprinting performance, including the use of theoretical models. Eight rugby players, eight track sprinters and eight competitive sportsmen, all elite national or regional competitors, performed sprints over 15 m and 35 m with times recorded over 0-15 m and 30-35 m. Isokinetic torque was measured at the knee, hip and ankle joints at low (1.05 rad s(-1)), intermediate (2.09 or 2.62 rad s(-1)) and high (3.14 or 4.19 rad s(-1)) speeds during concentric and eccentric muscle actions. Using linear regression and expressing sprint performance as time, the strongest relationship, for the joint actions and speeds tested, was between concentric knee extension at 4.19 rad s(-1) and sprint performance (0-15 m times: r=-0.518, P< 0.01; 30-35 m times: r=-0.688, P< 0.01). These relationships were improved for 0-15 m, but not for 30-35 m, by expressing torque relative to body mass (0-15 m times: r=-0.581; 30-35 m times: r=-0.659). When 0-15 m performance was expressed as acceleration rather than time, the correlation was improved slightly (r=0.590). However, when the data (0-15 m times) were fitted to the allometric force model proposed by Gunther, 77% of the variance in concentric knee extension torque at 4.19 rad s(-1) could be explained by 0-15 m times, limb length (knee to buttocks) and body mass. The fitted parameters were similar to those from the theoretical model. These findings suggest that the relationship between isokinetic muscle strength and sprint performance over 0-15 m (during the acceleration phase) is improved by taking limb length and body mass into account.

A regression analysis of competitors' tournament results in relation to their world rankings was proposed to identify the effect of home advantage in international 'grand-slam' tennis and 'major' golf tournaments. The results provided little evidence of home advantage in either the grand-slam tennis or the golf tournaments held in 1993. The only possible evidence of home advantage was found in the Wimbledon tennis and the US Open golf championships. Even these findings can be explained, at least partially, by (1) the availability of information concerning the low world rankings of the British tennis players competing at Wimbledon, and (2) selective entry, allowing only the world's top-ranked foreign golfers into the US open golf tournament. In both cases, the lower ranking home competitors have a greater opportunity to perform above their anticipated world rankings. Therefore, provided entry into tennis and golf tournaments is truly 'open' to both the host nation's representatives and foreign competitors alike, home advantage does not appear to be a major factor influencing the competitors' performance in such competitions. These findings may be explained by the relatively objective nature of the scoring systems used in tennis and golf, unlike the subjective influence of refereeing decisions on the results of team-games such as soccer.

The aim of this study was to establish the validity of using shuttle run performance over 20 m to predict accumulated oxygen deficit. A new high-intensity shuttle run test (HIST) was devised, during which subjects ran to exhaustion at a speed equivalent to 120% of their performance attained during a progressive shuttle run test. The reliability of the new test was examined and found to be acceptable for 18 subjects who performed the test twice on separate days (r = 0.84, P < 0.01, study I). The discriminating ability of the new test was examined by comparing the distance covered by eight sprint- and eight endurance-trained athletes at 120% of their respective progressive shuttle run performances (615 +/- 111 vs 273 +/- 84 m, P < 0.01, study II). The strongest predictor of accumulated oxygen deficit for 27 subjects was found to be the geometric mean of the performances on the new test and on the progressive shuttle run test (r = 0.74, study III). The regression equation for this relationship was then used to estimate the accumulated oxygen deficit for a second group of 16 subjects (study IV). The correlation between the estimated and measured accumulated oxygen deficits was significant (r = 0.79, P < 0.01). The results from studies III and IV were therefore combined with the data from six new subjects to give a regression equation for predictive purposes based on 49 subjects.

Using the results from the end-of-season (1992-93) league tables, overall home advantage was confirmed in the eight major divisions of the English and Scottish football leagues. The degree of home advantage was found to vary significantly across the divisions. Furthermore, these divisional differences in home advantage were found to be significantly associated with the mean attendance of each division. In an attempt to understand these findings, every occurrence of two influential events (either a sending-off or penalty scored) reported in a national Sunday newspaper was recorded. The overall frequency of both sendings-off and penalties scored favoured the home side, but again this was not constant across the divisions. In divisions with large crowds, the percentage of home sendings-off was relatively small (30%), compared with no difference (50%) in divisions with smaller crowds. Similarly, the percentage of penalties scored by home sides in divisions with the largest crowds was large ( > 70%), in contrast to little or no advantage in divisions with smaller crowds. Two possible explanations for these findings were proposed. Either larger crowds were able to provoke the away player into more reckless behaviour (real fouls), or influence the referee into believing that the away player had committed more fouls (perceived fouls).

Recent studies have suggested that determining the accumulated oxygen deficit (AOD), in units of oxygen equivalents per kilogram body mass (ml O2 Eq.kg-1), during a short exhaustive run, may represent a non-invasive measure of anaerobic metabolism. However, there is little information either on the reproducibility of the laboratory determination or its relationship with human performance. The purpose of the present investigation was to determine the reproducibility of AOD during inclined treadmill running (study 1), and to examine its relationship with short-distance running performance (study 2). Twelve volunteers (11 males, 1 female) took part in study 1 and AOD was determined (relative exercise intensity approximately 120% VO2 max) on two separate occasions at a treadmill inclination of 10.5%; the laboratory-measured AOD values were 65.2 +/- 10.9 vs 66.3 +/- 12.5 ml O2 Eq.kg-1, respectively (r = 0.94, P < 0.01). A second subject group (10 males, 4 females) undertook study 2, which investigated AOD values and track times over 100, 400 and 800 m. The mean calculated AOD value was 66.1 +/- 12.0 ml O2 Eq.kg-1, and the average track times were 13.6 +/- 1.3, 60.9 +/- 6.8 and 138.8 +/- 18.5 s for the 100, 400 and 800 m, respectively. The r-values for the relationship between AOD and track time were -0.88, -0.82 (P < 0.01) and -0.61 (P < 0.05) for the 100, 400 and 800 m, respectively. The results of the present study suggest that the AOD (ml O2 Eq.kg-1) is a unique and reproducible physiological characteristic which is strongly correlated with sprint capacity.

Eighteen games players (9 males, 9 females) performed 30 maximum 6-sprints on a non-motorized treadmill. Each sprint was preceded by a 60-s jog at 40% maximum speed and was followed by a 54-s walk at 20% maximum speed. Thus, the entire test was of 60-min duration. The subjects were then randomly assigned to three groups and repeated the 1-h test 24 h later after consuming either a high, normal or low carbohydrate diet (79 +/- 3, 47 +/- 8, 12 +/- 1% CHO, respectively). During trial 1, mean power output declined from 653 +/- 131 to 600 +/- 158 W during the 30 sprints (P < 0.01) and power output was lower during trial 2 than during trial 1 (n = 18, P < 0.01). During trial 2, there were no differences in sprint performance between the dietary groups for the exercise test as a whole (trial 2 mean power lower than trial 1 by 0.2, 0.5 and 5.0% for the high, normal and low CHO groups, respectively; N.S.), but if only the first nine sprints are considered, then the high CHO group performed better than the low CHO group (P < 0.05). Blood lactate and glucose concentrations were lower during trial 2 than trial 1 by 4.5, 13.8 and 29.0% (lactate) and 14.9, 11.3 and 35.8% (glucose) for the high, normal and low CHO groups, respectively (both P < 0.01). Thus, both the metabolic responses to, and the performance of, maximum intermittent exercise were reduced when the test was repeated after 24 h recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Because moods are transitory emotional states that can be influenced by a range of personality and environmental factors, the notion that elite athletes will always tend to produce a so-called iceberg profile of mood, and that less successful performers will not, is open to question. Evidence for such a claim is based principally upon descriptive studies. The present experiment used the POMS inventory as a predictor of cross-country running performance among a group of experienced male athletes. Race times from two competitive events were plotted against each of six mood factors. Using data from race 1, a multiple-regression model--incorporating the interdependence of tension, anger and depression--was able to predict rank order of finishing positions for race 2 with acceptable accuracy (rs = 0.74, P less than 0.01). The present approach differs from the traditional model of mood research in sport in that it provides a prescriptive, rather than a descriptive, focus. Although the model that has been developed appears promising, it is likely that in sports where demands on athletes are very different from those made upon cross-country runners, an alternative model may be required.