Competition and training demands of junior Sprint Kayak athletes

University of Technology, Sydney. Faculty of Health.Introduction: Sprint Kayak is an Olympic sport where women race over 200-m and 500-m and men compete over 200 and 1000-m. In 2009 the 200-m event was included into the Olympic Games’ program replacing the men’s 500-m events and providing the women with an additional event. Currently, little research is available on the demands of the 200-m event. With the inclusion of this short distance event, the training practices require review, especially in the case of young developing athletes, as this group may begin to specialise their training toward this new format. Therefore, the overall goals of this thesis were to: 1) gain a better understanding of the racing and physiological demands in Sprint Kayak, 2) develop specific methods for monitoring training and performance and 3) compare methods for training well-trained junior Sprint Kayak athletes. The results of four separate studies were reported in six manuscripts. Study 1: The split –time results from six Sprint Kayak world championships (ntotal = 486) were pooled and the pacing strategies and performance analysed according to race level (Finals A and B) and boat (K1, K2 and K4). Collectively, the world-class Sprint Kayak athletes present different pacing strategy according to final A and B), boat class (K1, K2 and K4) and from year to year. Study 2: Examined the relationships between physiological variables, including VO2max, maximal aerobic power (MAP), lactate threshold (LT2), whole body (VO2kinetics) and muscle oxygen kinetics (MO2kinetics), muscle oxygenation parameters and on-water time-trial performances. The results showed physiological variables correlated with performance in both 200-m and 1000-m events. Furthermore, the muscle oxygenation parameters increased the predictive power of these physiological variables highlighting the importance of muscle oxygen extraction for the 200-m time-trial. Study 3: Tested a specific performance test (SKtest) in the laboratory and in the field for validity (as a performance and fitness measure) and reliability (part A). In addition, the test sensitivity was assessed during a normal training period (part B) in a separate group of well-trained junior Sprint Kayak athletes. Part A - Participants (n = 11) completed a standard incremental kayak step test in the laboratory, a SKtest consisting of two sets of ten 100-m efforts with 20 s rest between efforts and 1000-m between sets in both laboratory and on-water and on-water time trials over 200 and 1000-m. Part B – Another group of athletes (n = 8) performed weekly trials of the short version of the SKtest for four weeks, in their usual training environment. The results showed the SKtest to be valid, reliable and sensitive for monitoring fitness and performance changes. Study 4: Tested the validity of methods for quantifying training load and established the relationships between training loads, physiological variables and on-water performance in well-trained junior Sprint Kayak athletes. The results demonstrated the validity of the session-RPE method for quantifying training loads in Sprint Kayak. Moreover, the inverse relationships between physiological variables, performance and training loads showed that aerobically fitter and faster athletes have lower perceived training loads when external loads are controlled. Study 5: Compared the power outputs and acute physiological responses (i.e. heart rate [HR], blood lactate [BLa¯], VO2, and tissue saturation index [TSI])) of common repeated sprint (RS) and high-intensity aerobic (HIA) interval training sessions in well-trained junior Sprint Kayak athletes. Two different RS training sessions consisting of a shorter 10 s repeat effort session (2 sets of 10 s efforts with 10 s rest between efforts and eight minutes between sets) and a longer 30-s repeat effort session (6 x 30 s efforts with 210 s rest). The HIA sessions included a shorter (2 x 3 min efforts with 3 min rest between efforts, and 5 min between sets) and a longer 2-km (3 x 2 km efforts on a 15 min cycle) interval training sets. The results showed the physiological responses and external loads to the main body the HIA interval sessions were considerably different from RS sessions, with the exception of TSI which was similar for all. Mixed modelling showed significant random variation for the time spent in different training zones for mean power output and VO2. The present study highlighted distinct differences in the HR, VO2, [BLa¯], and perceptual responses to common RS and HIA training, with the shorter RS sessions placing a greater stimulus on glycolytic pathways, and the longer HIA sessions requiring greater energetic demands. Importantly, large inter-individual physiological responses were observed across each of the different training sessions. These findings highlight the need to individualise training programs for Sprint Kayak based on the athletes’ characteristics and demands of competition. Study 6: Compared the effects of 5 weeks of RS and HIA interval training on physiological (VO2max, MAP, LT2, VO2kinetics and MO2kinetics) and performance (200 and 1000-m on water time trial) variables in well-trained junior Sprint Kayak athletes using matched-groups randomised design. The groups were matched for physical fitness and on-water kayak performance. In addition to their usual training, the RS training group completed a shorter 10 s repeat effort session (2 sets of 10 s efforts with 10 s rest between efforts and 8 minutes between sets) and longer 30-s repeat effort session (6 x 30 s efforts with 210 s rest), where each session was completed once per week. Similarly, the HIA interval training group completed a three-minute (2 x 3 min efforts with 3 min rest between efforts and 5 min between sets) and longer 2-km aerobic training (3 x 2 km efforts on a 15 min cycle) session once each week during the study in addition to their usual training. Results showed that the RS and HIA interval training interventions elicited trivial changes in maximal indicators of aerobic fitness (i.e. VO2max and maximal HR) and trivial and small on-water performance (i.e. time trials over 200 and 1000-m, respectively) in both groups. In contrast, submaximal physiological responses (i.e. lactate threshold) were trivial whereas oxygen kinetics presented small-to-moderate improvements after five weeks (~19 training sessions) performed by both RS and HIA groups. This information suggests that physiological and performance characteristics are very stable in well-trained junior Sprint Kayak athletes. It seems that either larger loads of RS or HIA interval training or longer training periods are required to elicit larger changes in specific physiological adaptations in well-trained junior Sprint Kayak athletes

Correction:A study of the structural properties of sites modified by the O-linked 6-N-acetylglucosamine transferase

[This corrects the article DOI: 10.1371/journal.pone.0184405.]

Behavioral and cardiopulmonary effects of dexmedetomidine alone and in combination with butorphanol, methadone, morphine or tramadol in conscious sheep

Objective: To compare cardiopulmonary and sedative effects following administration of dexmedetomidine alone or with butorphanol, methadone, morphine or tramadol in healthy sheep. Study design: Randomized crossover study. Animals: Six Santa Inês sheep, five females, one male, aged 12–28 months and weighing 40.1 ± 6.2 kg. Methods: Sheep were assigned treatments of dexmedetomidine (0.005 mg kg−1; D); D and butorphanol (0.15 mg kg−1; DB); D and methadone (0.5 mg kg−1; DM); D and morphine (0.5 mg kg−1; DMO); or D and tramadol (5.0 mg kg−1; DT). All drugs were administered intravenously with at least 7 days between each treatment. Rectal temperature, heart rate (HR), respiratory rate (fR), invasive arterial pressure, blood gases and electrolytes were measured prior to administration of drugs (baseline, T0) and every 15 minutes following drug administration for 120 minutes (T15–T120). Sedation was scored by three observers blinded to treatment. Results: HR decreased in all treatments and fR decreased in DM at T30 and DMO at T30 and T45. PaCO2 was increased in D, DB and DM compared with baseline, and PaO2 decreased in D at T15 and T45; in DB at T15 to T75; in DM at T15 to T60; in DMO at T15; and in DT at T15, T30 and T75. There was a decrease in temperature in D, DB and DM. An increased pH was measured in D at all time points and in DT at T30–T120. inline image and base excess were increased in all treatments compared with baseline. There were no statistical differences in sedation scores. Conclusions and clinical relevance: The combination of dexmedetomidine with butorphanol, methadone, morphine or tramadol resulted in similar changes in cardiopulmonary function and did not improve sedation when compared with dexmedetomidine alone

Reconciling opposing views on carbon cycling in the coastal ocean: continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2

Despite their moderately-sized surface area, continental marginal seas play a significant role in the biogeochemical cycles of carbon, as they receive huge amounts of upwelled and riverine inputs of carbon and nutrients, sustaining a disproportionate large biological activity compared to their relative surface area. A synthesis of worldwide measurements of the partial pressure of CO2 (pCO2) indicates that most open shelves in the temperate and high latitude regions are under-saturated with respect to atmospheric CO2 during all seasons, although the low latitude shelves seem to be over-saturated. Most inner estuaries and near-shore coastal areas on the other hand are over-saturated with respect to atmospheric CO2. The scaling of air-sea CO2 fluxes based on pCO2 measurements and carbon mass balance calculations indicate that the continental shelves absorb atmospheric CO2 ranging between 0.33 to 0.36 Pg C yr-1 that corresponds to an additional sink of 27% to ~30% of the CO2 uptake by the open oceans based on the most recent pCO2 climatology (Takahashi et al., 2008; Deep-Sea Research II, this issue). Inner estuaries, salt marshes and mangroves emit up to 0.50 Pg C yr-1, although these estimates are prone to large uncertainty due to poorly constrained ecosystem surface area estimates. Nevertheless, the view of continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2 allows reconciling long-lived opposing views on carbon cycling in the coastal ocean

Age-related differences during visual search: the role of contextual expectations and cognitive control mechanisms

We explored the efficacy of drawing pictures as an encoding strategy to enhance memory performance in healthy older adults and individuals with probable dementia. In an incidental encoding phase, participants were asked to either draw a picture or write out each word from a set of 30 common nouns for 40 seconds each. Episodic memory for the target words was compared in a group of healthy older adults to individuals with probable dementia (MMSE/MOCA range 4 to 25). In two experiments we showed that recall and recognition performance was higher for words that were drawn than written out during encoding, for both participant groups. We suggest that incorporating visuo-perceptual information into memory enhanced performance by increasing reliance on visual-sensory brain regions, which are relatively intact in these populations. Our findings demonstrate that drawing is a valuable technique leading to measurable gains in memory performance for individuals with probable dementia

Mapping sustainability transitions in contemporary culture

This presentation draws from research conducted at an ongoing project, ‘SPLACH – Spatial Planning for Change’, which aims to inform a sustainability transition of the Lisbon Metropolitan Area urban planning, towards an improved food system, responding to contemporary cultural concerns. But where does contemporary culture really stand with respect to sustainability? Among many contenders for supplanting postmodernism, we would emphasize hypermodernism, digimodernism, metamodernism and transmodernism, since in many respects, these paradigmatic views are engaged with a sustainability transition. Here, we assess how history, technology and visual culture are valued in contemporaneity. This is done by intersecting our readings of cultural paradigms with key ideas about sustainability, drawn from the SPLACH literature review. Moreover, we highlight opportunities for urban design to accomodate a change towards sustainable urban environments.info:eu-repo/semantics/publishedVersio

Enhancing the Sensitivity of SMS Fiber Sensors by the Use of High Refractive Index Coatings

This paper presents a study on the behavior of single-mode/multimode/single-mode sensors with diamond-like carbon coating of high refractive index. Spectra and response for different values of the external medium refractive index are recorded and analyzed