A dynamical systems approach for the submaximal prediction of maximum heart rate and maximal oxygen uptake

This study examines the viability of utilizing a dynamical system model and heuristic parameter estimation algorithm to make predictions for maximum heart rate (\(\mathrm {HR_{max}}\)) and maximal oxygen uptake (\(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\)) using data collected from a submaximal testing protocol. \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\) is widely considered to be the best single measurement of overall fitness in humans. When a \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\) assessment is not available, \(\mathrm {HR_{max}}\) is often used to prescribe exercise intensities for training and rehabilitation. In the absence of maximal cardiopulmonary exercise testing (CPET), \(\mathrm {HR_{max}}\) and \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\) are typically estimated using traditional submaximal prediction methods with well-known limitations and inaccuracies. For this study, 12 regularly exercising healthy young adult males performed a bout of maximal CPET on a cycle ergometer to determine their true \(\mathrm {HR_{max}}\) and \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\). Participants also performed a submaximal bout of exercise at varied intensities. A dynamical system model and heuristic parameter estimation algorithm were applied to the submaximal data to estimate the participants’ \(\mathrm {HR_{max}}\) and \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\). The submaximal predictions were evaluated by computing the coefficient of determination \({R^2}\) and the standard error of the estimate (SEE) through comparisons with the true maximal values for \(\mathrm {HR_{max}}\) (\({R^2 = 0.96}\), SEE = 2.4 bpm) and \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\) (\({R^2 = 0.93}\), SEE = 2.1 mL kg\(^{-1}\) min\(^{-1}\)). The results from this study suggest that a dynamical system model and heuristic parameter estimation algorithm can provide accurate predictions for \(\mathrm {HR_{max}}\) and \(\dot{\mathrm {V}}{\mathrm {O_{2max}}}\) using data collected from a submaximal testing protocol.     

Body composition,metabolism, sleep,psychological and eating patterns of overtraining syndrome: Results of the EROS study (EROS-PROFILE)

Overtraining syndrome (OTS) is caused by an imbalance between training, nutrition and resting, and leads to decreased performance and fatigue; however, the precise underlying triggers of OTS remain unclear. This study investigated the body composition, metabolism, eating, sleeping patterns and mood states among participants with OTS. Selected participants were divided into OTS-affected athletes (OTS, n = 14), healthy athletes (ATL, n = 25), and healthy non-physically active controls (NCS, n = 12). Compared to ATL, OTS showed decreased sleep quality (p = 0.004); increased duration of work or study (p < 0.001); decreased libido (p = 0.024); decreased calorie (p < 0.001), carbohydrate (p < 0.001) and protein (p < 0.001) intakes; decreased mood states (p < 0.001); decreased basal metabolic rate (p = 0.013) and fat burning (p < 0.001); increased body fat (p = 0.006); decreased muscle mass (p = 0.008); and decreased hydration (p < 0.001). Levels were similar between OTS and NCS, except for worsened fatigue (p < 0.001) and vigour (p = 0.001) in OTS. Reduced calorie intake, worsened sleep, and increased cognitive activity are likely OTS triggers. OTS appears to induce dehydration, increase body fat, decrease libido, and worsen mood.     

Nearest neighbor search in metric spaces through Content-Addressable Networks

Most of the Peer-to-Peer search techniques proposed in the recent years have focused on the single-key retrieval. However, similarity search in metric spaces represents an important paradigm for content-based retrieval in many applications. In this paper we introduce an extension of the well-known Content-Addressable Network paradigm to support storage and retrieval of more generic metric space objects. In particular we address the problem of executing the nearest neighbors queries, and propose three different algorithms of query execution. An extensive experimental study on real-life data sets explores the performance characteristics of the proposed algorithms by showing their advantages and disadvantages.     

Mental Preparation Strategies of Olympic Archers During Competition: an exploratory investigation

Extensive interviews were conducted with all eight members of the 1996 Italian Olympic archery team regarding psychological factors associated with excellence and mental preparation strategies adopted during competition. Hierarchical inductive analysis revealed that positive expectations, concentration, facilitating emotions, body awareness and technical preparation were the mental aspects described by archers necessary for effective performance. Furthermore, the archers outlined a variety of mental preparation strategies including (a) autonomic control (emotion control, somatic control, internal dialogue, and focus on shooting), (b) imagery (visualization, self‐talk), (c) task‐focused concentration (body and action control, thought control) and (d) reaction to mistake (focus on correct execution, mistake disregard, shooting analysis). The idiosyncratic nature of the athlete's competition strategies highlights the need of gaining information about the particular demands of the sport and the mental procedures spontaneously developed by the performer, to provide suitable counselling or psychological intervention.     

The geometric curvature of the spine during the sirshasana,the yoga’s headstand

This study analysed the behaviour of the geometric curvature of the spine during sirshasana. The position of dorsal retroreflective markers was computed via stereophotogrammetric analysis in six males and five females (29.4 ± 8.8 years, 63.0 ± 11.4 kg, 1.66 ± 0.08 m [average ± standard deviation]). The spinal points were projected onto the sagittal and frontal planes of the trunk, a polynomial was fitted to the data and the two-dimensional geometric curvature was quantified. The inferior lumbar lordosis decreased compared to the orthostatic position and gait, which may favour the posterior protrusion of the lumbar spinal nucleus pulposus in people with posterior herniation. The lateral deviation at the middle of the thoracic spine increases during sirshasana, which may reflect increased difficulties for postural control and spinal loads. It could be useful for promoting positive spinal structural and functional chronic adaptations for healthy participants, if the yoga programme is carefully planned and the spinal alignment is carefully monitored during a headstand. However, it may aggravate some spinal diseases, especially scoliosis.     

Predicting athletes’ functional and dysfunctional emotions: The role of the motivational climate and motivation regulations

This study examined the relationships between perceptions of the motivational climate, motivation regulations, and the intensity and functionality levels of athletes’ pleasant and unpleasant emotional states. Specifically, we examined the hypothesised mediational role of motivation regulations in the climate–emotion relationship. We also tested a sequence in which emotions were assumed to be predicted by the motivational climate dimensions and then served as antecedents to variability in motivation regulations. Participants (N = 494) completed a multi-section questionnaire assessing targeted variables. Structural equation modelling (SEM) revealed that a perceived task-involving climate was a positive predictor of autonomous motivation and of the impact of functional anger, and a negative predictor of the intensity of anxiety and dysfunctional anger. Autonomous motivation was a partial mediator of perceptions of a task-involving climate and the impact of functional anger. An ego-involving climate was a positive predictor of controlled motivation, and of the intensity and impact of functional anger and the intensity of dysfunctional anger. Controlled motivation partially mediated the relationship between an ego-involving climate and the intensity of dysfunctional anger. Good fit to the data also emerged for the motivational climate, emotional states, and motivation regulations sequence. Findings provide support for the consideration of hedonic tone and functionality distinctions in the assessment of athletes’ emotional states.     

Measuring systematic long-term trajectories of school effectiveness improvement

The objective of this study was to identify trajectories of school improvement experienced by Chilean elementary schools over the last decade. Using econometric analysis and controlling for potential confounding factors, we created an index of school performance combining outcome indicators focused on different school dimensions, and estimated the 2002/2010 evolution of school improvement for all Chilean schools with available data. Broadly, we estimated an average increase in the school performance of about 0.19 SD; nevertheless, while 41% of the schools increased their educational performance by at least 0.1 SD, 25% of the schools decreased it during the same period; we also found that improving school effectiveness was more probable among schools with lower student socioeconomic status (SES). Finally, we found that the observed school improvement trajectories tended to be non-linear; thus, we estimated that only 13.4% of the schools improved their performance in a systematic way during the entire decade.     

Changing students' attitudes towards risky motor tasks: an application of the IZOF model

The aim of this study was to evaluate the effectiveness of an intervention programme in the physical education setting designed to change attitudes and emotions triggered by potentially risky motor tasks. The individual zones of optimal functioning (IZOF) model was used as a theoretical framework for the study. Italian male and female high school students (N = 84) took part in a 12 lesson intervention and in test-retest sessions. The assessment was conducted using the Motor Activity Anxiety Test to measure the students' approach-avoidance attitudes in the face of physical education tasks purported to engender strong emotional reactions. An idiosyncratic emotional profile was also implemented using a list of pleasant/unpleasant emotional adjectives. Two experimental groups were involved in the learning and performing of several potentially risky, highly emotion-arousing tasks, while two control groups were engaged in low-risk team sports. According to the hypothesis of the study, the programme was effective in decreasing the students' avoidance tendencies towards thrilling tasks and in increasing optimal-pleasant emotions. Our findings also demonstrated the feasibility and utility of applying the IZOF model to the context of physical education.