All for One and One for All! Disparity Between Overall Crew’s and Individual Rowers’ Pacing Strategies During Rowing

Purpose: This study examined individual contributions to overall pacing strategy during 2- and 5-km rowing trials in a cox-less-4 boat. Methods: A crew of 4 male rowers performed maximal-effort on-water trials over 2 and 5 km, and power output during every individual stroke was measured for each crew member. Mean overall boat and individual rower stroke power were calculated for each 25% epoch (25% of total strokes taken), and power for each individual epoch was calculated as a percentage of mean power maintained over the entire distance. The coefficient of variation was used to determine stroke-to-stroke and epoch-to-epoch variability for individual rowers and the overall boat. Results: In both trials, the overall pacing strategy consisted of a high power output in the initial 25% that decreased in the middle 50% and increased again in the final 25%. However, individual rower data indicate wide variation in individual power profiles that did not always mimic the overall boat profile. Conclusions: This study demonstrates that overall boat power profiles during 2- and 5-km rowing trials are similar to velocity profiles previously reported for individual ergometry and on-water racing events. However, this over-all profile is achieved despite considerable variation in individual rower profiles. Further research is warranted to determine the mechanisms through which individual contributions to overall pacing strategy are regulated and the effectiveness or oth-erwise of seemingly disparate individual strategies on overall performance

Tangibly Reducing Sedentariness in Office Workers

It is claimed sedentariness is as much a threat to long- term health as smoking or unhealthy eating, and is not mitigated by bursts of physical activity. Desk bound office workers are particularly vulnerable to this risk, given the inherently sedentary nature of their roles. To tackle this problem in HCI, we have focused largely on smartphones apps whilst embracing a general trend towards automating data collection of behavior. We argue that placing technologies in the environment, leveraging ambient displays and Tangible User Interfaces (TUIs), can offer a more effective approach for tackling sedentary behaviors in an office environment. We include a brief design of a device we intend to use to evaluate these ideas

The Influence of Performance Level, Age and Gender on Pacing Strategy During a 100-km Ultramarathon

The aim of this study is to analyse the influence of performance level, age and gender on pacing during a 100-km ultramarathon. Results of a 100-km race incorporating the World Masters Championships were used to identify differences in relative speeds in each 10-km segment between participants finishing in the first, second, third and fourth quartiles of overall positions (Groups 1, 2, 3 and 4, respectively). Similar analyses were performed between the top and bottom 50% of finishers in each age category, as well as within male and female categories. Pacing varied between athletes achieving different absolute performance levels. Group 1 ran at significantly lower relative speeds than all other groups in the first three 10-km segments (all P < 0.01), and significantly higher relative speeds than Group 4 in the 6th and 10th (both P < 0.01), and Group 2 in the 8th (P = 0.04). Group 4 displayed significantly higher relative speeds than Group 2 and 3 in the first three segments (all P < 0.01). Overall strategies remained consistent across age categories, although a similar phenomenon was observed within each category whereby ‘top’ competitors displayed lower relative speeds than ‘bottom’ competitors in the early stages, but higher relative speeds in the later stages. Females showed lower relative starting speeds and higher finishing speeds than males. ‘Top’ and ‘bottom’ finishing males displayed differing strategies, but this was not the case within females. Although pacing remained consistent across age categories, it differed with level of performance within each, possibly suggesting strategies are anchored on direct competitors. Strategy differs between genders and differs depending on performance level achieved in males but not females

More pace variation and pack formation in successful world-class 10,000-m runners than in less successful competitors

Purpose To determine different relationships between, and predictive ability of, performance variables at intermediate distances with finishing time in elite male 10,000 m runners. Methods Official electronic finishing and 100 m split times of the men’s 10,000 m finals at the 2008 and 2016 Olympic Games and IAAF World Championships in 2013 and 2017 were obtained (125 athlete performances in total). Correlations were calculated between finishing times and positions and performance variables relating to speed, position, time to the leader and time to the runner in front at 2000, 4000, 6000, 8000 and 9900 m. Stepwise linear regression analysis was conducted between finishing times and positions and these variables across the race. One-way ANOVA was performed to identify differences between intermediate distances. Results The standard deviation and kurtosis of mean time, skewness of mean time and position and time difference to the leader were either correlated with or significantly contributed to predictions of finishing time and position at one of the analysed distance at least (0.81 ≥ r ≥ 0.30 and 0.0001 ≤ P ≤ 0.03, respectively). These variables also displayed variation across the race (0.0001 ≤ P ≤ 0.05). Conclusions The ability to undertake a high degree of pace variability, mostly characterised by acceleration in the final stages, is strongly associated with the achievement of high finishing positions in championship 10000 m racing. Furthermore, the adoption and maintenance of positions close to the front of the race from the early stages is important to achieve a high finishing position

Individual performances relative to season bests in major track running championship races are distance-, position- and sex-dependent

Objectives. To compare season’s best times preceding major championships (SBprior) and times achieved in major championship flat track races. Material and methods. 2320 men’s and 2312 women’s finishing times over 100 m, 400 m, 800 m, 1500 m and 5000 m at the International Association of Athletics Federations (IAAF) World Championships and Olympic Games from 1999 to 2019, and their SBprior, were obtained via IAAF open-access website. Paired t-tests were used to compare major championship times and SBprior for groups across sex in each event. Repeated measures ANOVA was used to examine differences in the percentage of SBprior achieved in the major championship races (%SBprior) between groups and sexes. Results. Finishing time performances were generally slower than SBprior. The difference between SBprior and championship performances increased with distance run and across preliminary rounds and finals. Differences in %SBprior between sexes were found in non-medal finalists in the 800 m and 5000 m (p < 0.001, ES ≥ 0.72). Conclusions. 1500 m and 5000 m athletes competing at major championships should train and be physiologically prepared to sustain non-even paces and produce a fast endspurt to achieve an optimal performance

Different Psychophysiological Responses to a High-intensity Repetition Session Performed Alone or in a Group by Elite Middle-distance Runners

Internal training load refers to the degree of disturbance in psychophysiological homeostasis provoked by a training session and has been traditionally measured through session-RPE, which is the product of the session Rate of Perceived Exertion (RPE) and the duration. External training load refers to the actual physical work completed, and depends on session volume, intensity, frequency and density. Drafting, which is achieved by running closely behind another runner has been demonstrated to reduce the energy cost of running at a fixed speed and to improve performance. Therefore, it is hypothesized that psychophysiological responses might reflect different levels of internal load if training is performed individually or collectively. 16 elite middle-distance runners performed two high-intensity training sessions consisting of 4 repetitions of 500 m separated by 3 minutes of active recovery. Sessions were performed individually and collectively. Times for each repetition, RPE, core affect (valence and felt arousal) and blood lactate concentrations [BLa] were measured after each repetition. Main time effect was significant and increased across repetitions for [BLa] and RPE (p <0.001), and decreased for valence (p =0.001). Main group effect was significant and values were higher when training individually for [BLa] (p =0.003) and RPE (p =0.001), and lower for valence (p =0.001). No differential responses were found between conditions in terms of repeat time or felt arousal. Findings demonstrate that elite middle-distance athletes running collectively display lower levels of internal training load compared to running alone, despite external training load being similar

Distributions and abundances of Pacific sardine (Sardinops sagax) and other pelagic fishes in the California Current Ecosystem during spring 2006, 2008, and 2010, estimated from acoustic–trawl surveys

The abundances and distributions of coastal pelagic fish species in the California Current Ecosystem from San Diego to southern Vancouver Island, were estimated from combined acoustic and trawl surveys conducted in the spring of 2006, 2008, and 2010. Pacific sardine (Sardinops sagax), jack mackerel (Trachurus symmetricus), and Pacific mackerel (Scomber japonicus) were the dominant coastal pelagic fish species, in that order. Northern anchovy (Engraulis mordax) and Pacific herring (Clupea pallasii) were sampled only sporadically and therefore estimates for these species were unreliable. The estimates of sardine biomass compared well with those of the annual assessments and confirmed a declining trajectory of the “northern stock” since 2006. During the sampling period, the biomass of jack mackerel was stable or increasing, and that of Pacific mackerel was low and variable. The uncertainties in these estimates are mostly the result of spatial patchiness which increased from sardine to mackerels to anchovy and herring. Future surveys of coastal pelagic fish species in the California Current Ecosystem should benefit from adaptive sampling based on modeled habitat; increased echosounder and trawl sampling, particularly for the most patchy and nearshore species; and directed-trawl sampling for improved species identification and estimations of their acoustic target stre

Don’t Kick the Habit: The Role of Dependency in Habit Formation Apps

Habit formation apps are intended to help instigate and maintain new behaviors. Prior research has established that these apps mostly do not support the theoretical ‘habit’ construct defined in psychology, yet are generally popular and well reviewed in app stores. This apparent mismatch between theory and ‘in-the-wild’ usage has not been investigated to date. Through an in-depth qualitative study of a popular application Lift, this research establishes that common techniques such as reminders and streaks are effective at supporting repetition of new behaviors, but at the same time create a dependency: on-going app use is often required to achieve lasting change. This dependency introduces fragility in users’ attempts to change their behavior, as they often abandon the app and subsequently disengage with their new behaviors

Fortune Favors the Brave. Tactical Behaviors in the Middle Distance Running Events at the 2017 IAAF World Championships.

Purpose: To assess tactical and performance factors associated with progression from qualification rounds in the 800 m and 1500 m running events at the 2017 IAAF World Championships Methods: Official results were used to access final and intermediate positions and times,as well as performance characteristics of competitors. Shared variance between intermediate positions and rank order lap times (ROSPT) with finishing positions were calculated, along with probability of automatic qualification, for athletes in each available race position at the end of every 400 m lap. Differences in race positions and lap times relative to season´s best (SB) performances were assessed between automatic qualifiers (AQ), fastest losers (FL), and non-qualifiers (NQ). Results: Race positions at the end of each 400 m lap remained more stable through 800 m races than 1500 m races. Probability of automatic qualification decreased with both race position and ROSPT on each lap, although ROSPT accounted for a higher degree of shared variance than did intermediate position. In the 1500 m event FL ran at a higher percentage of SB speed, and adopted positions closer to the race lead in the early stages. This was not the case in the 800 m. Conclusions: Intermediate positioning and the ability to produce a fast final race segment are strongly related to advancement from qualification rounds in middle distance running events. The adoption of a more ‘risky’ strategy characterized by higher speeds relative to SB may be associated with increased likelihood of qualification as FL in the 1500 m event

ATRX has a critical and conserved role in mammalian sexual differentiation

BACKGROUND X-linked alpha thalassemia, mental retardation syndrome in humans is a rare recessive disorder caused by mutations in the ATRX gene. The disease is characterised by severe mental retardation, mild alpha-thalassemia, microcephaly, short stature, facial, skeletal, genital and gonadal abnormalities. RESULTS We examined the expression of ATRX and ATRY during early development and gonadogenesis in two distantly related mammals: the tammar wallaby (a marsupial) and the mouse (a eutherian). This is the first examination of ATRX and ATRY in the developing mammalian gonad and fetus. ATRX and ATRY were strongly expressed in the developing male and female gonad respectively, of both species. In testes, ATRY expression was detected in the Sertoli cells, germ cells and some interstitial cells. In the developing ovaries, ATRX was initially restricted to the germ cells, but was present in the granulosa cells of mature ovaries from the primary follicle stage onwards and in the corpus luteum. ATRX mRNA expression was also examined outside the gonad in both mouse and tammar wallaby whole embryos. ATRX was detected in the developing limbs, craniofacial elements, neural tissues, tail and phallus. These sites correspond with developmental deficiencies displayed by ATR-X patients. CONCLUSIONS There is a complex expression pattern throughout development in both mammals, consistent with many of the observed ATR-X syndrome phenotypes in humans. The distribution of ATRX mRNA and protein in the gonads was highly conserved between the tammar and the mouse. The expression profile within the germ cells and somatic cells strikingly overlaps with that of DMRT1, suggesting a possible link between these two genes in gonadal development. Taken together, these data suggest that ATRX has a critical and conserved role in normal development of the testis and ovary in both the somatic and germ cells, and that its broad roles in early mammalian development and gonadal function have remained unchanged for over 148 million years of mammalian evolution.This study was supported by a National Health and Medical Research Council R D Wright Fellowship to AJP the Australian Research Council Centre of Excellence in Kangaroo Genomics and a Federation Fellowship to MBR