Optimization of training for professional rugby union players: investigating the impact of different small-sided games models on GPS-derived performance metrics

Introduction: Professional rugby union players can improve their performance by engaging in small-sided games (SSGs), which simulate the movement patterns of the game. This study collected metrics related to running performance and mechanical workload and their relative values from both forward and back positions, aiming to explore the impact of different SSGs factors on athlete workload, as well as the workload difference between official games (OGs) and SSGs.Methods: The monitored GPS data were collected from SSGs with different player numbers and pitch sizes (five sessions), SSG rules (5 weeks, four sessions per week), and OGs conducted throughout the year. Additionally, the study compared changes in players’ sprinting performance before and after two SSG sessions.Results: Backs had greater workload than forwards. Less space and number of players SSG (4 vs. 4, 660 m2) was conducive to facilitating training for players in acceleration and deceleration. Conversely, larger spaces were associated with improved running performance. However, the introduction of a floater had no significant impact on performance improvement. Additionally, the 7 vs. 4 model (seven players engaged with four opponents) resulted in the greatest workload during medium-hard accelerations (F = 52.76–88.23, p < 0.001, ηp2 = 0.19–0.28). Japan touch model allowed for more high-speed running training (F = 47.93–243.55, p < 0.001, ηp2 = 1.52). The workload performed by SSGs can almost cover that of OGs (F = 23.36–454.21, p < 0.05, ηp2 = 0.03–0.57). In the context of ηp2, values around 0.01, 0.06 and 0.14 indicate small, medium and large effects respectively.Discussion: However, given the significantly higher workload of SSGs and the slight decrease in sprinting performance, further research is required to examine the training patterns of SSGs. This study provided insight into the impact of player numbers, pitch size, and rules on rugby-specific SSGs. Coaches should optimize SSG setups for enhanced training outcomes, ensuring the long-term development of physical capacity, technical and tactical skills

Changes in training load, running performance, lower body power and biochemical characteristics of back players throughout a professional Rugby Union season

The aim of this study was to observe and quantify changes in training load (TL), running performance, lower body power and biochemical characteristics of professional rugby union back players over an entire season. Eight professional players (age: 25.8 ± 4.6 y) participated in this study. Session-RPE (S-RPE) and microtechnologies (GPS) were used for assessing training load (TL). During the season, running performance was monitored using the YoYo Recovery Test Level-2 (YYRT2) and lower body power performance using the drop jump (DJ) test. Changes in hematological, endocrine and muscle damage parameters were examined through 3 blood samples taken at separate times throughout the season. TL progressively and significantly (p < 0.001) decreased throughout the season particularly due to the decrease in the training volume. The last blood sample of the season revealed a significant (p < 0.001) increase in hematological parameters and a significant increase (p < 0.01) in cortisol blood concentration without change in the testosterone/cortisol ratio. No significant change in YYRT2 performance was observed over the season, while DJ test performance was significantly lower during the first 2 blocks of the season compared to other blocks. The training volume showed a significant negative correlation with DJ-test performances (TD: r = -0.49 and S-RPE: r = -0.40, p < 0.001). Although there was a decrease in training volume throughout the season, there was no significant changes in running performance. Furthermore, lower body power production showed a significant increase in particular during the last part of the season

The Relationships Between Skeletal Muscle Index and Bone Variables in a Group of Young Adults

International audienceThe purpose of this study was to investigate the relationships between skeletal muscle index (SMI) and bone variables in a group of young adults. Three hundred and thirty-five young adults (129 men and 206 women) whose ages ranged from 18 to 35 yr voluntarily participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. Body composition, bone mineral content (BMC), bone mineral density (BMD), geometric indices of hip bone strength and trabecular bone score (TBS) were determined for each individual by Dual-energy X-ray absorptiometry (DXA). Appendicular skeletal mass (ASM, in kg) was calculated by summing the muscle masses of the 4 limbs, assuming that all nonfat and nonebone mass is skeletal muscle. Skeletal muscle index (SMI) was defined as ASM/height². In young men, SMI was positively correlated to WB BMC (r = 0.63; p < 0.001), WB BMD (r = 0.53; p < 0.001), L1-L4 BMC (r = 0.33; p < 0.001), L1-L4 BMD (r = 0.30; p < 0.001), L1-L4 TBS (r = 0.26; p < 0.01), TH BMC (r = 0.61; p < 0.001), TH BMD (r = 0.46; p < 0.001), FN BMC (r = 0.51; p < 0.001), FN BMD (r = 0.46; p < 0.001), FN cross-sectional area (CSA) (r = 0.56; p < 0.001), FN cross-sectional moment of inertia (CSMI) (r = 0.52; p < 0.001) and FN section modulus (Z) (r = 0.54; p < 0.001) but negatively correlated to FN strength index (SI) (r = -0.24; p < 0.01). In young women, SMI was positively correlated to WB BMC (r = 0.61; p < 0.001), WB BMD (r = 0.60; p < 0.001), L1-L4 BMC (r = 0.35; p < 0.001), L1-L4 BMD (r = 0.33; p < 0.001), L1-L4 TBS (r = 0.29; p < 0.001), TH BMC (r = 0.61; p < 0.001), TH BMD (r = 0.53; p < 0.001), FN BMC (r = 0.45; p < 0.001), FN BMD (r = 0.49; p < 0.001), FN CSA (r = 0.60; p < 0.001), FN CSMI (r = 0.52; p < 0.001), and FN Z (r = 0.40; p < 0.001) but negatively correlated to FN SI (r = -0.20; p < 0.01). The current study suggests that SMI is a positive determinant of bone mineral density and geometric indices of hip bone strength in young adults

Effects of different training intensities in high-intensity interval training (HIIT) on maximal aerobic velocity, hematological and muscle-damage markers in healthy young adults

International audienceThis study aimed to examine the effects of two high-intensity interval training programs (HIIT) on maximal aerobic velocity (MAV), hematological variations and muscle damage markers in young healthy adults. Twenty-nine male physical education students, aged 20.3 +/- 3.3 years, volunteered to participate in this study, and were randomly assigned to a control group (CG, n = 9) or two intervention groups (group 1 or 2). Intervention group 1 (n = 10) exercised at 100% of their MAV (EG(100)) while group 2 (n = 10) exercised at 110% MAV (EG(110)). Before and after the eight week training program, blood samples were drawn at rest, before, and after an intermittent exercise. Aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), C reactive protein (CRP), creatine kinase (CK) concentrations and hematological parameters (white blood cells [WBC], monocytes [MO], lymphocytes [LY], neutrophil [NE]) and lactate dehydrogenase (LDH) were measured. Post-hoc tests showed that MAV was significantly higher in EG(110) compared to EG(100) after HIIT (p &lt; 0.01, eta(2)(p) = 0.05), whilst ALAT, ASAT, and CPR were significantly lower (p &lt; 0.01; 0.02 &lt; eta(2)(p) &lt; 0.11) in EG(110) compared to EG(100). Moreover, post-hoc tests indicated that LY decreased significantly (p &lt; 0.001, eta(2)(p) = 0.21) only for EG(110). Furthermore, there were significant positive correlations for both EG(100) and EG(110) between MAV and ALAT (r = 0.66, p = 0.044 and r = 0.64, p = 0.041 respectively), CK (r = 0.67, p = 0.031 and r = 0.86, p = 0.030, respectively), LDH (r = 0.74, p = 0.014, and r = 0.071, p = 0.021, respectively). In addition, there was a significant positive correlation for both, EG(100) and EG(110) between MAV and LY (r = 0.79, p &lt; 0.01; r = 0.72, p &lt; 0.05, respectively). Concerning the relationship between MAV and NE, there was a significant positive correlation (r = 0.66; p &lt; 0.05) only for EG(110). Findings from this study revealed that HIIT at 110% MAV was more efficient to improve MAV and reduce muscle damage. In addition, we observed significant associations between performance improvements (MAV) and markers of muscle damage

La recherche scientifique et les sports collectifs. Exemple du handball.

National audienceno abstrac

Mesure ambulatoire des mouvements thoraciques et abdominaux (développement d un prototype pour l estimation de la dépense énergétique)

La sédentarité est actuellement considérée par l'Organisation Mondiale de la Santé (OMS) comme un facteur de risque de morbidité et de mortalité majeur. Elle est assimilée à une maladie qui serait la dixième cause de mortalité dans le monde. Dans les pays européens, et en France particulièrement, l'activité physique a diminuée d'environ 15% ces vingt dernières années. Il en résulte de nombreux décès, de nombreuses maladies et des milliards de frais de traitement chaque année. De plus, de nombreux travaux indiquent que l'activité physique régulière prévient les troubles métaboliques, amenant une diminution de la morbidité et de la mortalité associées. Néanmoins, des interrogations restent posées sur la relation liant l activité physique (la dose) et ses bénéfices pour la santé (la réponse). Ces réflexions s'inscrivent dans le cadre d'enjeux majeurs de société, et justifient l'intérêt porté sur la mise en place de nouvelles méthodes d'estimation de la dépense énergétique. L objectif de ce travail de thèse est donc de proposer une nouvelle méthode d'estimation de la dépense énergétique. Les activités explorées s'apparentent aux postures du corps (assis et debout) et aux activités ambulatoires (activité de marche), qui représentent la majeure partie de la dépense énergétique en condition de vie quotidienne. Notre première étude a ainsi montrée l'intérêt d'utiliser la ventilation pour estimer une dépense énergétique au cours d'activité de différentes intensités. Notre seconde étude a permis de valider un nouvel appareil, léger, portable et non invasif d'estimation de la ventilation, à partir de la mesure des distances antéropostérieures thoraciques et abdominales, ainsi que les distances longitudinales antérieures et postérieures. Enfin, notre troisième étude valide ce système, comme outil d'estimation de la dépense énergétique en condition de repos et d'exerciceCurrently physical inactivity is considered by the World Health Organization (WHO) as a major risk factor of morbidity and mortality. It is comparable with a disease which would be the 10th cause of mortality in the world. In the European countries and in France particularly, physical activity has decreased by approximately 15% these twenty last years. It results from many deaths, many diseases and billions expenses of medical treatment each year. Moreover, numerous studies indicate that regular physical activity prevents metabolic disorders, bringing a decrease in morbidity and mortality associated. Nevertheless, many questions remain unanswered about the relationship between physical activity (dose) and its health benefits (the response). These reflections are major society issues and justify the interest on the development of new methods to estimate energy expenditure. The aim of this thesis is to propose a new method to estimate energy expenditure. The activities explored are body postures (sitting and standing) and ambulatory activity (walking activity), which represent the major part of energy expenditure in free-living conditions. Thus, our first study showed the interest to use ventilation to estimate energy expenditure during activities of different intensities. Our second study aimed to validate a new device, lightweight, portable and non-invasive able to estimate ventilation from the anteroposterior displacement of the rib cage and abdomen and the axial displacements of the chest wall and the spine. Finally, our third study validates this system as a device able to estimate energy expenditure in resting and exercise conditionsRENNES2-BU Centrale (352382101) / SudocSudocFranceF

Évolution des disparités de la mortalité infantile entre les départements français

Contribution au Ve Colloque national de démographie du CNRS, Nice, 14-16 avril 197

Physiological aspects of competitive tennis : a review of the current literature.

International audienceno abstrac

Influence of court surface on physiological demands during tennis matches in 19-23 years old players (transition to professional phase).

International audienceno abstrac

Facteurs de variation de la cinétique de VO2 lors de deux modalités d'exercice (Intermittente / Continue) chez des spécialistes de demi-fond et de fond

NANTES-BU Sciences (441092104) / SudocSudocFranceF