Sodium bicarbonate ingestion increases glycolytic contribution and improves performance during simulated taekwondo combat

Purpose: To investigate the effect of sodium bicarbonate (NaHCO₃) on performance and estimated energy system contribution during simulated taekwondo combat. Methods: Nine taekwondo athletes completed two experimental sessions separated by at least 48?h. Athletes consumed 300?mg/kg body mass of NaHCO₃ or placebo (CaCO₃) 90?min before the combat simulation (three rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration [La^?] and rating of perceived exertion (RPE) were measured before and after each round, whereas heart rate (HR) and the estimated contribution of the oxidative (W_OXI), ATP (adenosine triphosphate)-phosphocreatine (PCr) (W_PCR), and glycolytic (W_{[ La^? ]}) systems were calculated during the combat simulation. Results: [La^?] increased significantly after NaHCO₃ ingestion, when compared with the placebo condition (+14%, P?=?0.04, d?=?3.70). NaHCO₃ ingestion resulted in greater estimated glycolytic energy contribution in the first round when compared with the placebo condition (+31%, P?=?0.01, d?=?3.48). Total attack time was significantly greater after NaHCO₃ when compared with placebo (+13%, P?=?0.05, d?=?1.15). W_OXI, W_PCR, VO₂, HR and RPE were not different between conditions (P?>?0.05). Conclusion: NaHCO₃ ingestion was able to increase the contribution of glycolytic metabolism and, therefore, improve performance during simulated taekwondo combat.     

The transfer of strength and power into the stroke biomechanics of young swimmers over a 34-week period

The purpose of this study was to learn the interplay between dry-land strength and conditioning, and stroke biomechanics in young swimmers, during a 34-week training programme. Twenty-seven swimmers (overall: 13.33?±?0.85 years old; 11 boys: 13.5?±?0.75 years old; 16 girls: 13.2?±?0.92 years old) competing at regional- and national-level competitions were evaluated. The swimmers were submitted to a specific in-water and dry-land strength training over 34 weeks (and evaluated at three time points: pre-, mid-, and post-test; M1, M2, and M3, respectively). The 100-m freestyle performance was chosen as the main outcome (i.e. dependent variable). The arm span (AS; anthropometrics), throwing velocity (TV; strength), stroke length (SL), and stroke frequency (SF; kinematics) were selected as independent variables. There was a performance enhancement over time (M1 vs. M3: 68.72?±?5.57?s, 66.23?±?5.23?s; Δ?=??3.77%; 95% CI: ?3.98;?3.56) and an overall improvement of the remaining variables. At M1 and M2, all links between variables presented significant effects (p?p?≤?.05). Between M1 and M3, the direct effect of the TV to the stroke biomechanics parameters (SL and SF) increased. The model predicted 89%, 88%, and 92% of the performance at M1, M2, and M3, respectively, with a reasonable adjustment (i.e. goodness-of-fit M1: χ²/df?=?3.82; M2: χ²/df?=?3.08; M3: χ²/df?=?4.94). These findings show that strength and conditioning parameters have a direct effect on the stroke biomechanics, and the latter one on the swimming performance.     

Learning through chemistry simulations: an analysis of cognitive skill levels

Education and Information Technologies - This paper presents an analysis of cognitive skill levels expressed in high school students’ performance using laboratory simulations. We address...     

Using sensemaking as a lens to assess student learning on corporate social responsibility and sustainability

Prior literature suggests that teaching corporate social responsibility (CSR) and sustainability has led to little development of students' reflexive engagement with the challenges of sustainable development. To shed light on this criticism, we apply sensemaking—as entailing the three stages of scanning for information, interpreting it and identifying alternatives of action—to CSR/sustainability education. Analysing cognitive maps of CSR, drawn by undergraduate finalists from a UK business school, we find that students are able to produce complex cognitive maps in terms of scanning for information; however, cognitive bottlenecks occur at the second and third stages of sensemaking. A key pedagogical challenge is, therefore, to support students in moving beyond scanning towards developing meaning and acting on that basis. By introducing a sensemaking lens, we add to a deeper understanding of the complexities associated with CSR education as it aids (or impedes) critical engagement and action.     

Exploring the emotional aspect in Learner’s personal annotation colors

Education and Information Technologies - A personal annotation is a rich object with an important cognitive facet. In the e-Learning context, learners’ annotation can contain important...     

Lessons from the famous 17th-century paradox of the Chevalier de Méré

We take advantage of a combinatorial misconception and the famous paradox of the Chevalier de Méré to present the multiplication rule for independent events; the principle of inclusion and exclusion in the presence of disjoint events; the median of a discrete-type random variable, and a confidence interval for a large sample. Moreover, we pay tribute to our original bibliographic sources by providing two computational tools to facilitate the students' insights on these topics.