Diurnal variation in cycling performance: Influence of warm-up

We examined the effects of time of day on a cycling time trial with and without a prolonged warm-up, among cyclists who tended towards being high in “morningness”. Eight male cyclists (mean?±?s: age = 24.9?±?3.5 years, peak power output = 319?±?34?W, chronotype = 39?±?6 units) completed a 16.1-km time trial without a substantial warm-up at both 07:30 and 17:30?h. The time trial was also completed at both times of day after a 25-min warm-up at 60% of peak power. Power output, heart rate, intra-aural temperature and category ratings of perceived exertion (CR-10) were measured throughout the time trial. Post-test blood lactate concentration was also recorded. Warm-up generally improved time trial performance at both times of day (95% CI for improvement = 0 to 30?s), but mean cycling time was still significantly slower at 07:30?h than at 17:30?h after the warm-up (95% CI for difference = 33 to 66?s). Intra-aural temperature increased as the time trial progressed (P <?0.0005) and was significantly higher throughout the time trials at 17:30?h (P = 0.001), irrespective of whether the cyclists performed a warm-up or not. Blood lactate concentration after the time trial was lowest at 07:30?h without a warm-up (P = 0.02). No effects of time of day or warm-up were found for CR-10 or heart rate responses during the time trial. These results suggest that 16.1-km cycling performance is worse in the morning than in the afternoon, even with athletes who tend towards ‘morningness’, and who perform a vigorous 25-min warm-up. Diurnal variation in cycling performance is, therefore, relatively robust to some external and behavioural factors.     

Modelling and analysing track cycling Omnium performances using statistical and machine learning techniques

Abstract

This article describes the utilisation of an unsupervised machine learning technique and statistical approaches (e.g., the Kolmogorov-Smirnov test) that assist cycling experts in the crucial decision-making processes for athlete selection, training, and strategic planning in the track cycling Omnium. The Omnium is a multi-event competition that will be included in the summer Olympic Games for the first time in 2012. Presently, selectors and cycling coaches make decisions based on experience and intuition. They rarely have access to objective data. We analysed both the old five-event (first raced internationally in 2007) and new six-event (first raced internationally in 2011) Omniums and found that the addition of the elimination race component to the Omnium has, contrary to expectations, not favoured track endurance riders. We analysed the Omnium data and also determined the inter-relationships between different individual events as well as between those events and the final standings of riders. In further analysis, we found that there is no maximum ranking (poorest performance) in each individual event that riders can afford whilst still winning a medal. We also found the required times for riders to finish the timed components that are necessary for medal winning. The results of this study consider the scoring system of the Omnium and inform decision-making toward successful participation in future major Omnium competitions.     

Relationships of hip abductor strength,neuromuscular control,and hip width to femoral length ratio with peak hip adduction angle in healthy female runners

ABSTRACT

A large peak hip adduction angle during running is a risk factor for several overuse injuries in women. The purpose of this study was to determine if female runners with a large peak hip adduction angle have differences in eccentric hip abductor muscle strength, hip neuromuscular control, and/or hip width to femoral length ratio (HW:FL) compared to those with a small angle. Hip adduction during running, hip strength, hip control, and HW:FL were measured in sixty healthy female runners (1.66 ± 0.06 m; 63.2 ± 8.3 kg; 27 ± 6 years). Data from twenty runners with the largest and twenty with the smallest peak hip adduction angles were analysed. Between-group differences in hip strength, control, and HW:FL were determined using independent t-tests (p < 0.05). Variables that were significantly different between groups were entered into a regression model. Runners in both groups had similar hip strength (p = 0.90) and control (p = 0.65). HW:FL was greater in the large peak angle group (p = 0.04), but only explained a small amount of peak hip adduction angle variance for all sixty runners (R² = 0.05). Alarge peak hip adduction angle in some healthy female runners may simply be instinctive as there were no deficiencies in the strength or neuromuscular control constructs assessed.     

Nineteenth-Century Journalism Online—The Market Versus Academia?

In a climate of fear about funding for libraries and the arts, the preservation of many periodicals and newspapers is under threat. Digitisation is therefore justifiable as a conservation directive however what of those volumes that are not chosen? Are we creating an alternative version of Victorian culture through so selective a gaze? Indeed, who is choosing these titles? There is a question of access, both of what material is available to digitise and also what it is perceived ‘the audience’ want. However, a further question is raised—who are ‘the audience’? What are these archives going to be used for? This article will examine the different forms of nineteenth-century periodical and newspaper archives that are available, how they are organised and who their perceived audience is, before going on to consider the pedagogical utility of such sites. How can we enhance students' understanding of nineteenth-century culture by using these archives in our lecture theatres? And if we do, what are the implications for research in the future?     

Effects of two football stud configurations on biomechanical characteristics of single-leg landing and cutting movements on infilled synthetic turf

Multiple playing surfaces and footwear used in American football warrant a better understanding of relationship between different combinations of turf and footwear. The purpose of this study was to examine effects of shoe and stud types on ground reaction force (GRF) and ankle and knee kinematics of a 180° cut and a single-leg 90° land-cut on synthetic turf. Fourteen recreational football players performed five trials of the 180° cut and 90° land-cut in three shoe conditions: non-studded running shoe, and football shoe with natural and synthetic turf studs. Variables were analyzed with a 3 × 2 (shoe × movement) repeated measures analysis of variance (p < 0.05). Peak vertical GRF (p < 0.001) and loading rate (p < 0.001) were greater during 90° land-cut than 180° cut. For 180° cut, natural turf studs produced smaller peak medial GRFs compared to synthetic turf studs and non-studded shoe (p = 0.012). For land-cut, peak eversion velocity was reduced in running shoes compared to natural (p = 0.016) and synthetic (p = 0.002) turf studs. The 90° land-cut movement resulted in greater peak vertical GRF and loading rate compared to the 180° cut. Overall, increased GRFs in the 90° land-cut movement may increase the chance of injury.     

Performance effects of acute β-alanine induced paresthesia in competitive cyclists

β-alanine is a common ingredient in supplements consumed by athletes. Indeed, athletes may believe that the β-alanine induced paresthesia, experienced shortly after ingestion, is associated with its ergogenic effect despite no scientific mechanism supporting this notion. The present study examined changes in cycling performance under conditions of β-alanine induced paresthesia. Eight competitive cyclists (VO_2max = 61.8 ± 4.2 mL·kg·min^?1) performed three practices, one baseline and four experimental trials. The experimental trials comprised a 1-km cycling time trial under four conditions with varying information (i.e., athlete informed β-alanine or placebo) and supplement content (athlete received β-alanine or placebo) delivered to the cyclist: informed β-alanine/received β-alanine, informed placebo/received β-alanine, informed β-alanine/received placebo and informed placebo/received placebo. Questionnaires were undertaken exploring the cyclists’ experience of the effects of the experimental conditions. A possibly likely increase in mean power was associated with conditions in which β-alanine was administered (±95% CL: 2.2% ± 4.0%), but these results were inconclusive for performance enhancement (p = 0.32, effect size = 0.18, smallest worthwhile change = 56% beneficial). A possibly harmful effect was observed when cyclists were correctly informed that they had ingested a placebo (–1.0% ± 1.9%). Questionnaire data suggested that β-alanine ingestion resulted in evident sensory side effects and six cyclists reported placebo effects. Acute ingestion of β-alanine is not associated with improved 1-km TT performance in competitive cyclists. These findings are in contrast to the athlete’s “belief” as cyclists reported improved energy and the ability to sustain a higher power output under conditions of β-alanine induced paresthesia.     

One Man's Rubbish … Active Learning Using Old Bottle Tops

This is an activity for younger learners in which the concepts of relative frequency and probability are explored, illustrating how a creative, non‐transmission teaching approach using bottle tops can enable students to develop their understanding in an engaging fashion and at almost no cost.