A mathematical model of the oar blade – water interaction in rowing

Abstract

Our aim was to present a mathematical model of rowing and sculling that allowed for a comparison of oar blade designs. The relative movement between the oar blades and water during the drive phase of the stroke was modelled, and the lift and drag forces generated by this complex interaction were determined. The model was driven by the oar shaft angular velocity about the oarlock in the horizontal plane, and was shown to be valid against measured on-water mean steady-state shell velocity for both a heavyweight men's eight and a lightweight men's single scull. Measured lift and drag force coefficients previously presented by the authors were used as inputs to the model, whichs allowed for the influence of oar blade design on rowing performance to be determined. The commonly used Big Blade, which is curved, and it's flat equivalent were compared, and blade curvature was shown to generate a 1.14% improvement in mean boat velocity, or a 17.1-m lead over 1500 m. With races being won and lost by much smaller margins than this, blade curvature would appear to play a significant role in propulsion.     

Contextual factors on physical demands in professional women’s soccer: Female Athletes in Motion study

The aim of this study was to examine the impact of contextual factors on relative locomotor and metabolic power distances during professional female soccer matches. Twenty-eight players (forwards, n?=?4; midfielders, n?=?12; defenders, n?=?12) that competed in a 90-min home and away match (regular season only). The generalised estimating equations (GEE) was used to evaluate relative locomotor and metabolic power distances for three contextual factors: location (home vs. away), type of turf (natural vs. artificial), and match outcome (win, loss and draw). No differences were observed for home vs. away matches. Moderate-intensity running (20.0?±?1.0?m?min^?1 and 16.4?±?0.9?m?min^?1), high-intensity running (8.6?±?0.4?m?min^?1 and 7.3?±?0.4?m?min^?1) and high-metabolic power (16.3?±?0.5?m?min^?1 and 14.4?±?0.5?m?min^?1) distances were elevated on artificial turf compared to natural grass, respectively. Relative sprint distance was greater during losses compared with draws (4.3?±?0.4?m?min^?1 and 3.4?±?0.3?m?min^?1). Overall physical demands of professional women’s soccer were not impacted by match location. However, the elevation of moderate and high-intensity demands while playing on artificial turf may have implications on match preparations as well as recovery strategies.     

Exercise training increases the S-Klotho plasma levels in sedentary middle-aged adults: A randomised controlled trial. The FIT-AGEING study

ABSTRACT

This study aimed to investigate the effects of different training modalities on the soluble Klotho (S-Klotho) plasma levels in sedentary middle-aged adults. A total of 74 middle-aged adults (53.4 ± 5.0 years old; 52.7% women) were enrolled in the FIT-AGEING study. We conducted a 12-week randomised controlled trial. The participants were randomly assigned to 4 different groups: (i) a control group (no exercise), (ii) a physical activity recommendation from the World Health Organization group (PAR), (iii) a high intensity interval training group (HIIT), and (iv) a high intensity interval training group adding whole-body electromyostimulation training group (HIIT-EMS). S-Klotho plasma levels, anthropometric measurements, and body composition variables were measured before and after the intervention programme. All exercise training modalities induced an increase in the S-Klotho plasma levels (all P ≤ 0.019) without statistical differences between them (all P ≥ 0.696). We found a positive association between changes in lean mass index and changes in the S-Klotho plasma levels, whereas a negative association was reported between changes in fat mass outcomes and changes in the S-Klotho plasma levels after our intervention study. In conclusion, our results suggest that the link between exercise training and the increase in S-Klotho plasma levels could be mediated by a decrease of fat mass and an increase of lean mass.     

Historical Analysis of Participation in 161 km Ultramarathons in North America

Participation trends in 100 m (161 km) ultramarathon running competitions in North America were examined from race results from 1977 through 2008. A total of 32, 352 finishes accounted for by 9815 unique individuals were identified. The annual number of races and number of finishes increased exponentially over the study period. This growth in number of finishes occurred through a combination of (1) an increase in participation among runners ≥40 years of age from less than 40% of the finishes prior to the mid-1980s to 65–70% of the finishes since 1996, (2) a growth (p < 0.0001) in participation among women from virtually none in the late 1970s to nearly 20% since 2004, and (3) an increase in the average annual number of races completed by each individual to 1.3. While there has been considerable growth in participation, the 161 km ultramarathon continues to attract a relatively small number of participants compared with running races of shorter distances.     

Physical activity-related health competence as an integrative objective in exercise therapy and health sports – conception and validation of a short questionnaire

Health literacy represents an increasingly important subject in health sciences. This article initially illustrates a domain-specific model of physical activity-related health competence. Movement competence, control competence, and PA-specific self-regulation competence are described as sub-competencies.     

Urinary creatine and methylamine excretion following 4 × 5 g · day−1 or 20 × 1 g · day−1 of creatine monohydrate for 5 days

Abstract

In this study, we examined the effect of two creatine monohydrate supplementation regimes on 24-h urinary creatine and methylamine excretion. Nine male participants completed two trials, separated by 6 weeks. Participants ingested 4 × 5 g · day^?1 creatine monohydrate for 5 days in one trial and 20 × 1 g · day^?1 for 5 days in the other. We collected 24-h urine samples on 2 baseline days (days 1–2), during 5 days of supplementation (days 3–7), and for 2 days post-supplementation (days 8–9). Urine was assayed for creatine using high-performance liquid chromatography and methylamine using gas chromatography. Less creatine was excreted following the 20 × 1 g · day^?1 regime (49.25 ± 10.53 g) than the 4 × 5 g · day^?1 regime (62.32 ± 9.36 g) (mean ± s; P < 0.05). Mean total excretion of methylamine (n = 6) over days 3–7 was 8.61 ± 7.58 mg and 24.81 ± 25.76 mg on the 20 × 1 g · day^?1 and 4 × 5 g · day^?1 regimes, respectively (P < 0.05). The lower excretion of creatine using 20 × 1 g · day^?1 doses suggests a greater retention in the body and most probably in the muscle. Lower and more frequent doses of creatine monohydrate appear to further attenuate formation of methylamine.     

International comparison of differences in home advantage between level 1 and level 2 of domestic football leagues

The purpose of this study was to compare home advantage at the top two levels of the domestic leagues of a wide selection of countries worldwide. Limited previous work has been inconclusive with home advantage at level 2 appearing at least as high as at level 1. Home advantage was quantified for the most recent seven seasons of the top two levels for 47 countries worldwide and included 168,341 matches. A paired t?test was used to assess the difference between levels for each country. Home advantage was significantly more likely to be higher at level 2 than at level 1. The difference was especially apparent in Bosnia–Herzegovina, Serbia and Iran (all p?<?0.001). Kazakhstan was the only country with a significantly higher advantage at level 1. Possible factors that might be contributing to this finding include players and referees at level 1 being better trained to avoid being influenced by crowd support. Level 2 players may be more intimidated by performing away from home, less well equipped to cope with unfamiliar surroundings and routines, and will also have travelled in less comfort.     

The role of effort in moderating the anxiety – performance relationship: Testing the prediction of processing efficiency theory in simulated rally driving

Abstract

We tested some of the key predictions of processing efficiency theory using a simulated rally driving task. Two groups of participants were classified as either dispositionally high or low anxious based on trait anxiety scores and trained on a simulated driving task. Participants then raced individually on two similar courses under counterbalanced experimental conditions designed to manipulate the level of anxiety experienced. The effort exerted on the driving tasks was assessed though self-report (RSME), psychophysiological measures (pupil dilation) and visual gaze data. Efficiency was measured in terms of efficiency of visual processing (search rate) and driving control (variability of wheel and accelerator pedal) indices. Driving performance was measured as the time taken to complete the course. As predicted, increased anxiety had a negative effect on processing efficiency as indexed by the self-report, pupillary response and variability of gaze data. Predicted differences due to dispositional levels of anxiety were also found in the driving control and effort data. Although both groups of drivers performed worse under the threatening condition, the performance of the high trait anxious individuals was affected to a greater extent by the anxiety manipulation than the performance of the low trait anxious drivers. The findings suggest that processing efficiency theory holds promise as a theoretical framework for examining the relationship between anxiety and performance in sport.     

Motorische Leistungsfähigkeit von Kindern und Jugendlichen in Deutschland

Motor performance is an important health resource. Review articles revealed a decline of motor performance of approximately 10?% between 1975 and 2006. In the past most of the data available for such comparisons came from ad hoc studies with non-standardized methods. Within the framework of the ”Motorik-Modul“ (MoMo) study as part of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), it is possible for the first time to directly compare two cohorts in the ages of 4–17 years in a nationally representative database for Germany. The aim of this article is to report changes in motor performance of children and adolescents in the time period 2003–2006 (cohort baseline n = 4528) compared to 2009–2012 (cohort wave 1, n = 2820). Overall, it is clearly shown that the motor performance of children and adolescents in Germany did not decrease within the observational period of 6 years. The comparison of mean values of the baseline cohort compared to those of wave 1 showed that 28 out of 52 mean values of the two cohorts with a high probability did not differ based on 95?% confidence intervals (CI). In 24 out of the 52 mean values positive changes could be noted based on the individual 95?% CI values. There were more positive changes in primary school aged children than in other age groups. Within these positive changes, most effect sizes were small to medium. The results indicate that recent activities aiming at elevating motor performance levels may have started to make an impact and should be expanded, also in secondary schools. The comparative cohort study presented in this article is currently being checked by the ongoing MoMo wave 2 survey of 2014–2017.     

Female jockeys in Swedish horse racing 1890–2000: From minority to majority – complex causes

The aim of this paper is to describe and explain the changes in the gender balance of jockeyship in Swedish horse racing in the period 1890–2000. The change in gender coding, and its causes, are both complex. Two distinctive periods of change are argued to have been crucial, the 1940s and 1970s. In the first period women were given permission to ride in amateur races; in the second period they were allowed to become professionals. It is suggested here that the changes in the gender balance are explained by male support, the intersection of gender and social class and gender coding.     

Low-dose exercise training does not influence cardiac autonomic control in healthy sedentary men aged 55 – 75 years

Abstract

The purpose of this study was to evaluate the effects of a realistic, feasible, and commonly used fitness training programme on cardiac autonomic control in 14 sedentary men aged 62.0 ± 6.1 years (mean ± s). All participants performed a one-year fitness training programme in which training intensity and frequency were specifically chosen to be compliant for the majority of the participants (2 – 3 sessions per week at moderate intensity). At the same time, a reference group consisting of 15 sedentary age-matched men (age 64.2 ± 6.5 years) did not change their habitual physical activity. Measurements were performed before and after the training intervention. Cardiac autonomic control was inferred from resting values (supine and standing) of heart rate variability (HRV) computed in the frequency domain over 10-min intervals. Endurance capacity was evaluated during a maximal incremental bicycle ergometer test. In spite of an increase in peak oxygen consumption ([Vdot]O_2peak) by 6.4% after training, heart rate in the training group remained unchanged at rest and at the same metabolic demand. No changes in resting parameters of HRV were shown for either groups or positions. Results from this study provide no evidence of a clinically meaningful increase in the vagal modulation to the sinus node at rest after one year of low-volume and moderate-intensity fitness training in men aged 55 – 75 years.     

Re-engaging disengaged pupils in physical education: an appreciative inquiry perspective

Many children and young people enjoy physical education (PE), yet many do not, and subsequently become disengaged from PE. Previous research that has explored pupil disengagement from PE has focused on what teachers should do to re-engage their pupils, or has encouraged dis-engaged pupils to create a curriculum that they perceive to be socially and culturally relevant. While this research is extremely important, it does not highlight enough what teachers bring to the teaching and learning process. An alternative approach to understanding (dis)engagement in PE is to start by asking both teachers and pupils: what is currently working, why is it working, and what could be in the future? This ‘appreciative inquiry’ (AI) approach is underpinned by the belief that everyone and everything has strengths that can be developed, and that those strengths should be the starting point for change. Consequently, in establishing the use of AI as an important means of understanding and potentially enhancing PE pedagogy, this research sought to understand the successful teaching strategies developed by PE teachers to re-engage disengaged pupils. Importantly, in recognising the value of understanding pupil experiences we also explored and shared the success stories of the ‘re-engaged’ pupils. Finally, in extending the research in this area, we examined the impact that teacher engagement in the AI process had on their professional learning. As the teachers engaged in the AI process, they discussed, listened to (each other and their pupils), reflected and shared their success stories. This, in turn, appears to have encouraged them to re-articulate and re-enact their practice and learning within the context of a more positive future. They designed (and in some cases, co-design with their pupils) meaningful and empowering PE programmes for their ‘disengaged’ pupils and have subsequently made a commitment to future professional learning and inquiry.     

Visual dependency and postural control on swing performance in golf players

Abstract

Individuals have to reweight the respective contribution of the different sources of sensorial information for regulating posture and balance, especially during fine task execution. Given the evidences indicating strategy during swing performance as associated with prioritization of task-relevant visuospatial information for skill execution, the aim of the present work is to assess differences in visual dependency (VD) and postural control in a population of expert (EXP) and non-expert (NEXP) golfers when compared with healthy subjects (HC) and to discover possible relationships between these outcomes and swing performance. Thus, 15 golfers (EXP?=?7; NEXP?=?8) and 32 matched HC underwent otoneurological testing including video Head Impulse Test, posturography and Rod and Disk Test (RDT). Golf players also underwent a swing session procedure, which performance was measured by means of the Flightscope X2 Doppler-radar launch monitor system. EXP subjects demonstrated significant (p?<?0.05) lower values in i) counter-clockwise (CCW) and clockwise (CW) dynamic conditions when compared with both NEXP and HC subjects RDT outcome measures and ii) surface and length posturography values as compared with HC subjects. When treating golf players outcomes as ‘a continuum’, CCW and CW scores were found to positively correlate with both lateral distance and horizontal launch angle and to negatively correlate with spin rpm. In conclusion, the present study suggests that the high-level of visual-independency demonstrated by EXP subjects may be functionally related in expert golfers to an effective motor strategy preferentially not referring to an inappropriate reliance on visual input.     

‘Glorious Rounders’: The American Baseball Invasion of England in Two World Wars – Unappealing American Exceptionalism

During the two world wars of the twentieth century, American cultural wares were spread far and wide, and the global pervasiveness of US troops contributed significantly toward this development. One major aspect of an American serviceman's spare time was his involvement with sporting pursuits and, where possible, baseball matches were played, and even formalized, in the guise of exhibition matches played for war charities. Little, if anything, has been written about the matches that were played by the American military outside the USA from the perspective of the indigenous population. This paper examines the English response to the ‘friendly’ American invasion: the invasion of allied troops and their favourite pastime, baseball. In doing so, it is evident that even though, on the whole, the troops were welcome, there was a less than positive reception for the American national game.     

‘Samurai’ politics: Japanese cultural identity in global sport – The Olympic Games as a representational strategy

Modern Japan has considered global sport an appropriate forum for not only defining the national cultural identity of Japan but also for conducting its international diplomacy. The recent phenomenon of Japanese baseball athletes ‘defecting’ from Japanese leagues to play for the American baseball leagues has often been described in political terms. This paper argues that the current trend of analysing Japanese nationals playing baseball in America in political terms can be historically contextualized by reviewing the bids by Japanese cities for the 1940, 1964, 1998 and 2016 Olympic Games.     

Further variations on a theme: The games ethic further adapted – Scottish moral missionaries and muscular Christians in Malawi

This article examines theories and practices of moral and physical education among the Scottish missionaries in the Malawi region of south-central Africa during late nineteenth and early twentieth centuries. Within the wider history of British imperial education and the English public school games ethic, the Scottish missionaries of the Livingstonia and Blantyre missions offer an interesting and important counterpoint to their middle-class English counterparts. Although the Scots had their own distinct educational traditions which shaped their pedagogical programmes in Africa, they were not unaffected by the games ethic. Drill and team games gradually became an important part of missionary education in Blantyre and Livingstonia, with the holistic aim of developing the body, mind and moral character of the mission pupils. In Malawi, the games ethic, first introduced by middle-class Edinburgh missionaries, developed alongside an ‘industrial ethic’, and a distinctly ‘Scottish blend’ of missionary education that combined Scottish industrial and English non-industrial traditions emerged.     

Twenty-metre shuttle run test performance of English children aged 11 – 15 years in 2007: Comparisons with international standards

Abstract

Recent international normative data for the 20-m shuttle-run test demonstrated a below-average performance index for UK children. The aims of the present study were to create an international comparison of 20-m shuttle-run test performance in a sample of English children and to identify age- and sex-specific differences in test performance. Mass, stature, body mass index, and 20-m shuttle-run test performance were measured in 2041 children aged 11 – 15 years (963 boys, 1078 girls). Performance was expressed as maximum running velocity and a performance index was created by generating z-scores. The shuttle-run test performance index was higher than the existing published value (?0.046, 95% confidence interval [CI] ?0.070 to ?0.022) for all children (0.061, 95% CI = 0.006 to 0.115), for boys (0.075, 95% CI = ?0.022 to 0.171), and for girls (0.048, 95% CI = ?0.010 to 0.106). Boys' relative performance increased significantly (F = 4.43, P = 0.002) throughout the measured age range, whereas girls' relative performance tended to decrease (F = 1.98, P = 0.096). The results were favourable when compared with existing values. Differences in performance index may be due to the different geographical areas from which present and past samples were drawn. Reasons for differences in the performance indices between boys and girls warrant further investigation.     

The effect of caffeine ingestion on 8 km run performance in a field setting

Abstract

The aim of this study was to assess the effect of caffeine ingestion on 8 km run performance using an ecologically valid test protocol. A randomized double-blind crossover study was conducted involving eight male distance runners. The participants ran an 8 km race 1 h after ingesting a placebo capsule, a caffeine capsule (3 mg · kg^?1 body mass) or no supplement. Heart rate was recorded at 5 s intervals throughout the race. Blood lactate concentration and ratings of perceived exertion were recorded after exercise. A repeated-measures analysis of variance (ANOVA) identified a significant treatment effect for 8 km performance time (P < 0.05); caffeine resulted in a mean improvement of 23.8 s (95% confidence interval [CI] = 13.1 to 34.5 s) in 8 km performance time (1.2% improvement, 95% CI = 0.7 to 1.8%). In addition, a two-way (time × condition) repeated-measures ANOVA identified a significantly higher blood lactate concentration 3 min after exercise during the caffeine trial (P < 0.05). We conclude that ingestion of 3 mg · kg^?1 body mass of caffeine can improve absolute 8 km run performance in an ecologically valid race setting.