Effect of acute and chronic exercise on immunoendocrine responses in professional rugby union

Prolonged and intense exercise is known to modulate and suppress certain aspects of the immunoendocrine system. Such effects are thought to be largely mediated by the release of stress hormones and regulatory cytokines which originate from a variety of stress related paradigms in sport. These include acute physical exertion, chronic and repetitive exercise as well as other psychological and psychosocial aspects of training and competing in an elite environment. It may be of particular interest to study the effects of regular competition and training on immunoendocrine markers in rugby union players. At the professional level, rugby is an intense and physically demanding game where a significant amount of tissue trauma occurs as a result of the many game collisions. The aims of the studies outlined in this thesis were to determine the effects of acute, repeated and chronic exercise exposure on immunoendocrine markers and illness incidence in professional rugby union. Additional case studies were also undertaken to supplement main study findings. The first part of the thesis documented the effects of acute and repeated exercise on immunoendocrine markers in a cohort of international rugby union players. Data in study 1 showed that large disturbances in immunoendocine and hormone levels occur in players (n = 10) following game play. The magnitude of this response appeared dependent on game physicality (number of rucks/mauls, tackles) and the number of collisions players received during match play. Findings also showed suppression in host immunity, and in particular, innate immune function (neutrophil degranulation) which was not resolved 38 h (-29%) into the recovery period. In study 2, bloods were taken from players (n = 8) across a 21-day international rugby series. Data revealed that players entered the international camp with residual muscle damage (creatine kinase; CK) and inflammation (hs-CRP) following previous club involvement in European cup rugby. Further increases in stress related markers (cortisol, IL-6, CK, CRP) were not evident throughout the players time at the international training base. Conversely, a progressive increase in anabolic-catabolic balance (T/C ratio) was observed across time. In comparison to values on camp-entry (day 1), increases in T/C ratio were evident on day-5 (9.8%), day-7 (13%), day-19 (35%) and day-21 (45%) (P < 0.05). This data is suggestive of improved physiological recovery and was commensurate with team fitness goals (reduced volume + maintenance of training intensity) for that time. Findings suggest that monitoring of player club activities and training load preceding international duty is pertinent if they are required to represent their country inside 7 days. The second part of the thesis evaluated the stress induced effects of chronic rugby exposure in professional club players. Questionnaire data analysed from study 3 showed that players (n = 65) perceived current season length as being ‘too long’ (55%), ‘poorly structured’ (56%) and that game demands are increasing with time (52%). Furthermore, the majority of players (80%) felt that time ‘away’ from rugby was not sufficiently long enough and were in favour of a mid-season break (2 wks in duration). Investigation into the effects of chronic exercise on illness incidence, immunological and psychological state was carried out in a squad of club players (n = 30) over a competitive season (n = 48 wks) in studies 4-6. Findings revealed that specific periods in a rugby season resulted in disturbances to hormonal and immune status. These periods occurred following breaks in club game fixtures [November international and Six-nations period: February/early March], times of increased training intensity and increased ratio of conditioning/rugby activity. Peaks in number of upper respiratory illnesses (URIs) and disturbances in psychometric variables also occurred during these time periods. In 23% of all URIs, players reported that the presence of the illness either reduced activity (14.4%) or felt the need to go to bed (8.6%). Positional differences in variables were also observed. A higher incidence of URIs (3.4 vs 4.3) and lower concentrations of resting immune markers [salivary lysozyme: s-Lys (-31%); immunoglobulin A: s-IgA (-27%)] was observed in ‘backs’ (vs forwards) over the season. Higher mid-season cortisol levels was also observed in backs (P < 0.05) while conversely, greater concentrations of plasma CK and CRP were found in forwards throughout the season. These findings indicate positional specific differences in response to exercise load and point to the role of group specific recovery at certain times during the season. Data from study 6 showed that the number of training related complaints decreased across the season, findings which closely resembled corresponding decreases in plasma CRP values. This data is suggestive of a ‘repeated-bout’ effect or ‘contact adaptation’ in rugby union. Finally, comparison of methods used in the recording of illness data revealed that players were more honest when disclosing the existence of banal infections to a web-based training diary and under-reported infections to medical staff

TRIATHLON CYCLE-RUN TRANSITION: SEATED VERSUS ALTERNATING SEATED AND STANDING CYCLING

Nine experienced triathletes completed two trials of a cycle to run transition. During the last three minutes of a 30 minute cycling bout (at power output equal to lactate threshold) subjects either remained seated (SEAT), or alternated seated and standing cycling (30 s at a time) (ALT). Minimum and maximum knee angle and stride frequency were obtained at the end of a three minute control run (C) and at minutes 0, 2, & 4, of running after cycling transition. The only difference found by Two-Way Repeated Measures ANOVA (condition X minute) was that C was significantly different than minute 0 of the transition for stride frequency (

Athlete experiences of communication strategies in applied sports nutrition and future considerations for mobile app supportive solutions

Aim: This study aimed to explore athletes\u27 experiences and opinions of communication strategies in applied sports nutrition, as well as capture suggestions for future mobile app supportive solutions. Methods: A qualitative approach was used for this research. Data was generated from semi-structured focus groups (n = 9) with a purposive sample of 41 (male = 24, female = 17) full time professional athletes (mean age 24 ± 4.59) from five sports (football, rugby union, athletics, cycling, and boxing). Data was analyzed using reflexive thematic analysis. Results: The analysis identified four higher order themes and five sub themes. Athletes appear dissatisfied with the levels of personalization in the nutrition support they receive. Limited practitioner contact time was suggested as a contributing factor to this problem. Athletes acknowledged the usefulness of online remote nutrition support and reported a desire for more personalized technology that can tailor support to their individual needs. Conclusion: Athletes experienced a hybrid human-computer approach that combines in-person and remote digital methods to communicate with and receive information from practitioners. Mobile technology may now afford sports nutritionists with new opportunities to develop scalable solutions to support practice

A pilot sequential multiple assignment randomized trial (SMART) protocol for developing an adaptive coaching intervention around a mobile application for athletes to improve carbohydrate periodization behavior

Background: It has recently been identified that manipulating carbohydrate availability around exercise activity can enhance training-induced metabolic adaptations. Despite this approach being accepted in the athletic populations, athletes do not systematically follow the guidelines. Digital environments appear to allow nutritionists to deliver this intervention at scale, reducing expensive human coaching time. Yet, digitally delivered dietary behavior change interventions for athletes and the coaching strategy to support them are still novel concepts within sports nutrition. Methods/design: We aim to recruit 900 athletes across the UK. 500 athletes will be recruited to test the feasibility of a novel menu planner mobile application with coaching for 6 weeks. 250 athletes with pre-existing nutritionist support will also be recruited as control. We will then conduct a 4-week pilot sequential multiple assignment randomized trial (SMART) with an additional 150 athletes. In the SMART, athletes will be given the application and additional coaching according to their engagement responses. The primary outcomes are the mobile application and coach uptake, retention, engagement, and success in attaining carbohydrate periodization behavior. Secondary outcomes are changes in goal, weight, carbohydrate periodization self-efficacy, and beliefs about consequences. Due to the high attrition nature of digital interventions, all quantitative analyses will be carried out based on both the intention-to-treat and per-protocol principles. Discussion: This study will be the first to investigate improving carbohydrate periodization using a digital approach and tailored coaching strategies under this context. Foundational evidence from this study will provide insights into the feasibility of the digital approach

The Prospective Study of Epigenetic Regulatory Profiles in Sport and Exercise Monitored Through Chromosome Conformation Signatures

The integration of genetic and environmental factors that regulate the gene expression patterns associated with exercise adaptation is mediated by epigenetic mechanisms. The organisation of the human genome within three-dimensional space, known as chromosome conformation, has recently been shown as a dynamic epigenetic regulator of gene expression, facilitating the interaction of distal genomic regions due to tight and regulated packaging of chromosomes in the cell nucleus. Technological advances in the study of chromosome conformation mean a new class of biomarker—the chromosome conformation signature (CCS)—can identify chromosomal interactions across several genomic loci as a collective marker of an epigenomic state. Investigative use of CCSs in biological and medical research shows promise in identifying the likelihood that a disease state is present or absent, as well as an ability to prospectively stratify individuals according to their likely response to medical intervention. The association of CCSs with gene expression patterns suggests that there are likely to be CCSs that respond, or regulate the response, to exercise and related stimuli. The present review provides a contextual background to CCS research and a theoretical framework discussing the potential uses of this novel epigenomic biomarker within sport and exercise science and medicine

Multifunctional biomaterials from the sea: Assessing the effects of chitosan incorporation into collagen scaffolds on mechanical and biological functionality

Natural biomaterials such as collagen show promise in tissue engineering applications due to their inherent bioactivity. The main limitation of collagen is its low mechanical strength and somewhat unpredictable and rapid degradation rate; however, combining collagen with another material, such as chitosan, can reinforce the scaffold mechanically and may improve the rate of degradation. Additionally, the high cost and the risk of prion transmission associated with mammal-derived collagen has prompted research into alternative sources such as marine-origin collagen. In this context, the overall goal of this study was to determine if the incorporation of chitosan into collagen scaffolds could improve the mechanical and biological properties of the scaffold. In addition the study assessed if collagen, derived from salmon skin (marine), can provide an alternative to collagen derived from bovine tendon (mammal) for tissue engineering applications. Scaffold architecture and mechanical properties were assessed as well as their ability to support mesenchymal stem cell growth and differentiation. Overall, the addition of chitosan to bovine and salmon skin-derived collagen scaffolds improved the mechanical properties, increasing the compressive strength, swelling ratio and prolonged the degradation rate. Mesenchymal stem cell (MSC) attachment and proliferation was most improved on the bovine-derived collagen scaffold containing a 75:25 ratio of collagen:chitosan, and when MSC osteogenic and chondrogenic potential on the scaffold was assessed, a significant increase in calcium production (p < 0.001) and sulfated glycosaminoglycan (sGAG) production (p < 0.001) was observed respectively. Regardless of chitosan content, the bovine-derived collagen scaffolds out-performed the salmon skin-derived collagen scaffolds, displaying a larger pore size and higher percentage porosity, more regular architecture, higher compressive modulus, a greater capacity for water uptake and allowed for more MSC proliferation and differentiation. This versatile scaffold incorporating the marine biomaterial chitosan show great potential as appropriate platforms for promoting orthopaedic tissue repair while the use of salmon skin-derived collagen may be more suitable in the repair of soft tissues such as skin.This work was funded by Science Foundation Ireland (SFI) through the Research Frontiers Programme (Grant No. 11/RFP/ENM/3063) and by the European Regional Development Fund (ERDF) through INTERREG 2007-2013 Program (POCTEP project 0687_NOVOMAR_1_P). Bovine collagen materials were provided by Integra Life Sciences, Inc. through a Material Transfer Agreement. Salmon skins were kindly offered by Pingo Doce, Braga (Portugal)

Effect of acute and chronic exercise on immunoendocrine responses in professional rugby union

Prolonged and intense exercise is known to modulate and suppress certain aspects of the immunoendocrine system. Such effects are thought to be largely mediated by the release of stress hormones and regulatory cytokines which originate from a variety of stress related paradigms in sport. These include acute physical exertion, chronic and repetitive exercise as well as other psychological and psychosocial aspects of training and competing in an elite environment. It may be of particular interest to study the effects of regular competition and training on immunoendocrine markers in rugby union players. At the professional level, rugby is an intense and physically demanding game where a significant amount of tissue trauma occurs as a result of the many game collisions. The aims of the studies outlined in this thesis were to determine the effects of acute, repeated and chronic exercise exposure on immunoendocrine markers and illness incidence in professional rugby union. Additional case studies were also undertaken to supplement main study findings. The first part of the thesis documented the effects of acute and repeated exercise on immunoendocrine markers in a cohort of international rugby union players. Data in study 1 showed that large disturbances in immunoendocine and hormone levels occur in players (n = 10) following game play. The magnitude of this response appeared dependent on game physicality (number of rucks/mauls, tackles) and the number of collisions players received during match play. Findings also showed suppression in host immunity, and in particular, innate immune function (neutrophil degranulation) which was not resolved 38 h (-29%) into the recovery period. In study 2, bloods were taken from players (n = 8) across a 21-day international rugby series. Data revealed that players entered the international camp with residual muscle damage (creatine kinase; CK) and inflammation (hs-CRP) following previous club involvement in European cup rugby. Further increases in stress related markers (cortisol, IL-6, CK, CRP) were not evident throughout the players time at the international training base. Conversely, a progressive increase in anabolic-catabolic balance (T/C ratio) was observed across time. In comparison to values on camp-entry (day 1), increases in T/C ratio were evident on day-5 (9.8%), day-7 (13%), day-19 (35%) and day-21 (45%) (P < 0.05). This data is suggestive of improved physiological recovery and was commensurate with team fitness goals (reduced volume + maintenance of training intensity) for that time. Findings suggest that monitoring of player club activities and training load preceding international duty is pertinent if they are required to represent their country inside 7 days. The second part of the thesis evaluated the stress induced effects of chronic rugby exposure in professional club players. Questionnaire data analysed from study 3 showed that players (n = 65) perceived current season length as being ‘too long’ (55%), ‘poorly structured’ (56%) and that game demands are increasing with time (52%). Furthermore, the majority of players (80%) felt that time ‘away’ from rugby was not sufficiently long enough and were in favour of a mid-season break (2 wks in duration). Investigation into the effects of chronic exercise on illness incidence, immunological and psychological state was carried out in a squad of club players (n = 30) over a competitive season (n = 48 wks) in studies 4-6. Findings revealed that specific periods in a rugby season resulted in disturbances to hormonal and immune status. These periods occurred following breaks in club game fixtures [November international and Six-nations period: February/early March], times of increased training intensity and increased ratio of conditioning/rugby activity. Peaks in number of upper respiratory illnesses (URIs) and disturbances in psychometric variables also occurred during these time periods. In 23% of all URIs, players reported that the presence of the illness either reduced activity (14.4%) or felt the need to go to bed (8.6%). Positional differences in variables were also observed. A higher incidence of URIs (3.4 vs 4.3) and lower concentrations of resting immune markers [salivary lysozyme: s-Lys (-31%); immunoglobulin A: s-IgA (-27%)] was observed in ‘backs’ (vs forwards) over the season. Higher mid-season cortisol levels was also observed in backs (P < 0.05) while conversely, greater concentrations of plasma CK and CRP were found in forwards throughout the season. These findings indicate positional specific differences in response to exercise load and point to the role of group specific recovery at certain times during the season. Data from study 6 showed that the number of training related complaints decreased across the season, findings which closely resembled corresponding decreases in plasma CRP values. This data is suggestive of a ‘repeated-bout’ effect or ‘contact adaptation’ in rugby union. Finally, comparison of methods used in the recording of illness data revealed that players were more honest when disclosing the existence of banal infections to a web-based training diary and under-reported infections to medical staff.EThOS - Electronic Theses Online ServiceGBUnited Kingdo