The effects of acute and chronic sodium bicarbonate supplementation on high-intensity intermittent performance, recovery and subsequent performance in rugby union players

Exogenous ingestion of alkalising agents, such as sodium bicarbonate (SB), has been shown to enhance muscle buffering capacity, thereby delaying the metabolic acidosis associated with high-intensity exercise and potentially improving performance. Aim: The aim of this research was to examine the effects of acute and chronic SB supplementation and a placebo (PLA) on high-intensity intermittent performance, recovery and subsequent performance in trained rugby union players. Methods: This aim was achieved through the completion of three interconnected studies. Study 1 examined the effects of acute versus chronic SB supplementation on high-intensity intermittent performance as assessed by 6 x 10s maximal sprint tests on a cycle ergometer. Study 2 investigated effects of chronic SB supplementation on a specifically designed field-based, highintensity intermittent rugby sevens-specific protocol. Study 3 evaluated the effects of acute SB supplementation on an 80-minute high-intensity intermittent 15-a-side rugbyspecific protocol using elite females and sub-elite males. Results: In Study 1, acute SB supplementation demonstrated significant elevations in pre exercise levels for blood bicarbonate (StdHCO3 -), pH and base excess (BE-Ecf) but no significant improvement in peak power output (PPO), mean power output (MPO) or total work (TW). Chronic SB supplementation exhibited a significant increase in StdHCO3 - following Sprint 1. However, no significant differences in performance parameters were recorded for either acute or chronic SB supplementation when compared to the PLA trial. In Study 2, no significant differences in blood or performance related variables were observed between chronic SB and PLA supplementation trials. In Study 3, pre-exercise alkalosis was induced by acute SB supplementation in both elite females and sub-elite males. However, this did not translate into an ergogenic benefit to rugby union-specific performance. Vertical jump height and passing accuracy were significantly improved with PLA as opposed to SB supplementation in the elite female group. No significant differences in performance were observed between trials in the sub-elite male group. Conclusion: The major findings of this work suggest that pre-exercise metabolic alkalosis may be induced following acute but not chronic SB ingestion. However, results are inconclusive regarding the efficacy of acute or chronic SB ingestion to enhance performance in high intensity, intermittent performance indicative of the movement patterns and physiological demands associated with rugby union. Results also appear to indicate a high degree of individual variability, which, in part, may be due to potential gastrointestinal side effects of SB ingestion

A comparison of the physiological demands of two commercially available cycle ergometers in trained cyclists

Cycling ergometers are routinely used in a laboratory setting to evaluate physiological function and monitor changes in training status. One limitation of many cycle ergometers, in relation to the performance testing, is their inability to replicate the cyclist own specific cycling position thereby bringing the validity of the ergometer used into question. Purpose: The purpose of this study was to compare the aerobic and anaerobic energy demands of two commercially available cycle ergometers in trained cyclists. The first ergometer allowed full adjustment of cycling position and was electromagnetically braked (EB). The second ergometer allowed for saddle height adjustment only and was resistance braked (RB). Methods: Ten trained male cyclists were tested on 2 separate occasions within a 14 day period under the same conditions. Subjects performed a 30 second Wingate maximal sprint test followed 60 minutes later by a continuous maximal incremental step test on either the EB or RB cycle ergometer, in a random order. The Wingate test was performed at 9% of body mass and for 30 seconds with a 5 second speed up period. The incremental test started at 100W and increased in resistance by 50W every 3 minutes until volitional exhaustion. Heart rate, VO2, power output and blood lactate were measured during the maximal incremental test. Results: The results showed a significant difference (p<0.01) for the Wingate test between the RB and EB both in terms of peak power output (POmax) and mean power output (POmean) with subjects generating greater power outputs on the EB. During the maximal incremental test, significant differences (p<0.01) were found between EB and RB for submaximal power output, heart rate, and VO2 at both lactate threshold 1 (1mmol.l-1 rise above baseline, LT1) and onset of blood lactate accumulation (4mmol.l-1 blood lactate reference point, OBLA), as well as peak power output at VO2max (PVO2max). Conclusions: Overall it was shown that significant differences in physiological demands were present between the two ergometers under both anaerobic and aerobic conditions. This is may in part be explained by the different positions that the cyclists adopted on either ergometer. Further research is required to compare the findings of the current study with actual cycling performance

Monitoring Training Load Using the Acute: Chronic Workload Ratio in Non-Elite Intercollegiate Female Athletes

Monitoring training load and its progression in athletes is important to optimise adaptations to training while simultaneously preventing injury. A recent development in this field is the acute: chronic workload ratio (ACWR), which track s average acute training load against average chronic training load to describe training load progression. Furthermore, a new method of calculating the ACWR has been developed using exponentially weighted moving averages (EWMA) which accounts for the decay of fitness and fatigue. This study sought to investigate the relationship between the EWMA and ACWR (based upon session rating of perceived exertion (sRPE)), and injury risk in intercollegiate female athletes (N=4). Participants performed adductor squeeze tests (ASTs) once a week for 8 week s, while their training and wel lness were monitored with sRPE and a daily questionnaire respectively. A hierarchical regression demonstrated that monitoring of average sleep length, average stress, sRPE work loads and an EWMA provided the best model for predicting injury risk in athletes (R2 = 0.47). The findings indicate that the EWMA may be a effective training load monitoring tool than the ACWR model

Alpha Band Signatures of Social Synchrony

Previous research has reported changes in mu rhythm, the central rhythm of the alpha frequency band, in both intentional and spontaneous interpersonal coordination. The current study was designed to extend existing findings on social synchrony to the pendulum swinging task and simultaneously measured time unfolding behavioral synchrony and EEG estimation of mu activity during spontaneous, intentional in-phase and intentional anti-phase interpersonal coordination. As expected, the behavioral measures of synchrony demonstrated the expected pattern of weak synchronization for spontaneous coordination, moderate synchronization for intentional anti-phase coordination, and strong synchronization for in-phase coordination. With respect to the EEG measures, we found evidence for mu enhancement for spontaneous coordination in contrast to mu suppression for intentional coordination (both in phase and anti-phase), with higher levels of synchronization associated with higher levels of mu suppression in the right hemisphere. The implications of the research findings and methodology for understanding the underlying mechanisms contributing to social problems in psychological disorders, leader-follower relationships, and inter-brain dynamics are discussed

Learning to Sparsify Travelling Salesman Problem Instances

CPAIOR 2021: 18th International Conference on Integration of Constraint Programming, Artificial Intelligence, and Operations Research, Vienna, Austria, 5 - 8 July 2021In order to deal with the high development time of exact and approximation algorithms for NP-hard combinatorial optimisation problems and the high running time of exact solvers, deep learning techniques have been used in recent years as an end-to-end approach to find solutions. However, there are issues of representation, generalisation, complex architectures, interpretability of models for mathematical analysis etc. using deep learning techniques. As a compromise, machine learning can be used to improve the run time performance of exact algorithms in a matheuristics framework. In this paper, we use a pruning heuristic leveraging machine learning as a pre-processing step followed by an exact Integer Programming approach. We apply this approach to sparsify instances of the classical travelling salesman problem. Our approach learns which edges in the underlying graph are unlikely to belong to an optimal solution and removes them, thus sparsifying the graph and significantly reducing the number of decision variables. We use carefully selected features derived from linear programming relaxation, cutting planes exploration, minimum-weight spanning tree heuristics and various other local and statistical analysis of the graph. Our learning approach requires very little training data and is amenable to mathematical analysis. We demonstrate that our approach can reliably prune a large fraction of the variables in TSP instances from TSPLIB/MATILDA (>85%) while preserving most of the optimal tour edges. Our approach can successfully prune problem instances even if they lie outside the training distribution, resulting in small optimality gaps between the pruned and original problems in most cases. Using our learning technique, we discover novel heuristics for sparsifying TSP instances, that may be of independent interest for variants of the vehicle routing problem.Science Foundation IrelandOpen access funding provided by SF

Evidence of Embodied Social Competence During Conversation in High Functioning Children with Autism Spectrum Disorder

Even high functioning children with Autism Spectrum Disorder (ASD) exhibit impairments that affect their ability to carry out and maintain effective social interactions in multiple contexts. One aspect of subtle nonverbal communication that might play a role in this impairment is the whole-body motor coordination that naturally arises between people during conversation. The current study aimed to measure the time-dependent, coordinated whole-body movements between children with ASD and a clinician during a conversational exchange using tools of nonlinear dynamics. Given the influence that subtle interpersonal coordination has on social interaction feelings, we expected there to be important associations between the dynamic motor movement measures introduced in the current study and the measures used traditionally to categorize ASD impairment (ADOS-2, joint attention and theory of mind). The study found that children with ASD coordinated their bodily movements with a clinician, that these movements were complex and that the complexity of the children’s movements matched that of the clinician’s movements. Importantly, the degree of this bodily coordination was related to higher social cognitive ability. This suggests children with ASD are embodying some degree of social competence during conversations. This study demonstrates the importance of further investigating the subtle but important bodily movement coordination that occurs during social interaction in children with ASD

Physiological, haematological and performance characteristics of ultra endurance cyclists competing in the inaugural race around Ireland

Ultra-endurance events are a growing area within the sport of cycling. The Race Around Ireland (RAI) is a non-stop event where cyclists must complete the 2,170km route in under 96 hours. Purpose: The purpose of this study was to investigate the physiological, haematological and performance characteristics of members of a 4 man team before, during, and after the RAI. Methods: Four trained male cyclists were tested on 2 separate occasions within a 14 day period, with the second bout of testing performed within 7 days of the start of the race, to determine baseline values. Each cyclist completed a maximal incremental test on an electromagnetically braked cycle ergometer, commencing at 100W and increasing in intensity by 50W every 3 minutes until volitional exhaustion. Heart rate, VO2, power output and blood lactate were measured during the test. Following a standardized recovery period, each cyclist then completed a 20 minute maximal performance test (MPT) designed to mimic the demands of the RAI. Baseline blood samples were taken prior to each testing session to facilitate a detailed haematological analysis. Blood samples were also taken before the start of the race, at set intervals during the race, as well as on the race completion. Subjects were also weighed and urine samples collected at the same time points in order to assess hydration status using urine specific gravity (Usg). Further testing was carried out 7 days (haematology), and 14 days (haematology and MPT) post race. Results: No significant differences were found between the MPT results pre and post race. Significant differences were found for white blood cells (WBC) and granulocyte count (p<0.01), haematocrit, haemoglobin, lymphocytes, and red blood cells (p<0.05). No significant difference was observed for changes in body mass or Usg. Conclusions: Variations in WBC and other immune function markers showed initial decrease followed by a gradual elevation during the race. However this did not seem have an impact on the post race MPT. Although there appears to be a significant change in immune function during ultra endurance cycling, this may not lead to a subsequent performance decrement. However, analysis may be complicated by the specific race tactics adopted by the team during the race and the time course of post race assessment

Relationship Between Theory of Mind, Emotion Recognition, and Social Synchrony in Adolescents With and Without Autism

Difficulty in social communication and interaction is a primary diagnostic feature of ASD. Research has found that adolescents with ASD display various impairments in social behavior such as theory of mind (ToM), emotion recognition, and social synchrony. However, not much is known about the relationships among these dimensions of social behavior. Adolescents with and without ASD participated in the study. ToM ability was measured by viewing social animations of geometric shapes, recognition of facial emotions was measured by viewing pictures of faces, and synchrony ability was measured with a spontaneously arising interpersonal movement task completed with a caregiver and an intentional interpersonal task. Attention and social responsiveness were measured using parent reports. We then examined the relationship between ToM, emotion recognition, clinical measures of attention and social responsiveness, and social synchronization that arises either spontaneously or intentionally. Results indicate that spontaneous synchrony was related to ToM and intentional synchrony was related to clinical measures of attention and social responsiveness. Facial emotion recognition was not related to either ToM or social synchrony. Our findings highlight the importance of biological motion perception and production and attention for more fully understanding the social behavior characteristic of ASD. The findings suggest that the processes underlying difficulties in spontaneous synchrony in ASD are different than the processes underlying difficulties in intentional synchronization

Impairments of Social Motor Synchrony Evident in Autism Spectrum Disorder

Social interactions typically involve movements of the body that become synchronized over time and both intentional and spontaneous interactional synchrony have been found to be an essential part of successful human interaction. However, our understanding of the importance of temporal dimensions of social motor synchrony in social dysfunction is limited. Here, we used a pendulum coordination paradigm to assess dynamic, process-oriented measures of social motor synchrony in adolescents with and without autism spectrum disorder (ASD). Our data indicate that adolescents with ASD demonstrate less synchronization in both spontaneous and intentional interpersonal coordination. Coupled oscillator modeling suggests that ASD participants assembled a synchronization dynamic with a weaker coupling strength, which corresponds to a lower sensitivity and decreased attention to the movements of the other person, but do not demonstrate evidence of a delay in information transmission. The implication of these findings for isolating an ASD-specific social synchronization deficit that could serve as an objective, bio-behavioral marker is discussed

Wearable chemical sensing – sensor design and sampling techniques for real-time sweat analysis

Wearable chemical sensors have the potential to provide new methods of non-invasive physiological measurement. The nature of chemical sensors involves an active surface where a chemical reaction must occur to elicit a response. This adds complexity to a wearable system which creates challenges in the design of a reliable long-term working system. This work presents the design of a real-time sweat sensing platform to analyse sweat loss and composition. Sampling methods have an impact on composition therefore skin encapsulation needs to be avoided so as not to disrupt normal sweating patterns. Sensors ideally need to be placed close to the sampling site which may be subject to motion artefacts [1]. The design of this device takes into account sample collection and delivery, sensor placement and associated electronics. The overall design is ergonomic to interface with the contours of the body. Results of lab-based simulations and real-time exercise trials are presented. This device can offer valuable information regarding hydration status and electrolyte balance which may be especially important for optimised rehydration during or after sports activities. [1] Curto, V. F. S. Coyle, R. Byrne, N. Angelov, D. Diamond, F. Benito-Lopez., Sens. Actuators, B, 2012, 175, 263-270