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1.
Int J Sports Physiol Perform ; : 1-7, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39265975

RESUMO

BACKGROUND: In high-performance sport, the support provided by sport scientists and other staff can be a valuable resource for coaches and athletes. PURPOSE: We propose and detail here the approach of "minimal, adequate, and accurate" sport-science support to ensure that programs of work and solutions are both economical and effective. METHODS: Our support provision advocates for utilization of "minimal" resources (employing the least amount of time, tools, and funding) necessary to achieve the desired outcomes. We strive for "adequate" information that fulfills specific objectives without excess and with the requirement that methods and data used are "accurate" (valid and reliable). To illustrate the principles of this approach, we outline a real-world example of supporting 100-m track (athletics) sprinters preparing and competing in an international competition. The provision of performance support emphasizes an integrated approach, combining knowledge and insights from multiple sport-science disciplines. The key facets managed under this approach are (1) neuromuscular readiness, (2) wellness monitoring, (3) movement observation, (4) motivation, (5) biomechanics and performance analysis, and (6) qualitative feedback. These facets are based on the specific performance determinants and influencing factors of an event (100-m dash). CONCLUSIONS: Application of this quantitative and qualitative approach can enhance the ability to make informed decisions. Nevertheless, the approach must be planned, evaluated, and refined on a regular basis to enable effective decision making in sport-science support. The 3-element approach of "minimal, adequate, and accurate" should be codesigned and supported by the athletes, coaches, and staff to ensure successful implementation.

2.
J Funct Morphol Kinesiol ; 9(3)2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39311261

RESUMO

We investigated the acute biophysical responses of changing the mandibular position during a rowing incremental protocol. A World-class 37-year-old male rower performed two 7 × 3 min ergometer rowing trials, once with no intraoral splint (control) and the other with a mandibular forward repositioning splint (splint condition). Ventilatory, kinematics and body electromyography were evaluated and compared between trials (paired samples t-test, p ≤ 0.05). Under the splint condition, oxygen uptake was lower, particularly at higher exercise intensities (67.3 ± 2.3 vs. 70.9 ± 1.5 mL·kg-1·min-1), and ventilation increased during specific rowing protocol steps (1st-4th and 6th). Wearing the splint condition led to changes in rowing technique, including a slower rowing frequency ([18-30] vs. [19-32] cycles·min-1) and a longer propulsive movement ([1.58-1.52] vs. [1.56-1.50] m) than the control condition. The splint condition also had a faster propulsive phase and a prolonged recovery period than the control condition. The splint reduced peak and mean upper body muscle activation, contrasting with an increase in lower body muscle activity, and generated an energetic benefit by reducing exercise cost and increasing rowing economy compared to the control condition. Changing the mandibular position benefited a World-class rower, supporting the potential of wearing an intraoral splint in high-level sports, particularly in rowing.

3.
J Strength Cond Res ; 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39303201

RESUMO

ABSTRACT: Cardoso, F, Costa, MJ, Colaço, P, Vilas-Boas, JP, Pinho, JC, Pyne, DB, and Fernandes, RJ. Ventilatory and perceived ergogenic effects of mandibular forward repositioning during running at maximal oxygen uptake intensity. J Strength Cond Res XX(X): 000-000, 2024-Wearing an intraoral dental splint may enhance ventilatory function and exercise performance. Nineteen runners performed on a 400-m outdoor track: (a) an incremental protocol to assess the velocity at maximal oxygen uptake (vV̇o2max) and (b) 2 square wave bouts wearing 2 intraoral splints (with and without mandibular forward repositioning). The time until exhaustion at vV̇o2max (TLimv V̇o2max), ventilatory variables, oxygen uptake (V̇o2) kinetics, energetic profiling, perceived exertion and kinematics, were all measured. Ventilatory data were assessed breath-by-breath and perceived exertion evaluated using the Borg 6-20-point scale at the end of TLimv V̇o2max bouts. Images were recorded by video cameras (120 Hz) and kinematic measures retrieved using Kinovea. A paired t test was computed for comparison of splints (p ≤ 0.05). With (vs. without) mandibular forward repositioning, runners increased their TLimv V̇o2max by ∼6% (p = 0.03), coupled with higher ventilation (151 ± 22 vs. 147 ± 23 L·min-1, p = 0.04), end-tidal oxygen tension (114.3 ± 3.7 vs. 112.9 ± 3.9 mm Hg, p = 0.003), and lower inspiratory time (0.526 ± 0.083 vs. 0.540 ± 0.090 seconds, p = 0.02), despite similar V̇o2 kinetics (e.g., 49.0 ± 8.7 vs. 47.7 ± 8.6 ml∙kg∙min-1 of fast component amplitude) being observed. The energy expenditure was ∼8% higher (p = 0.03) with the mandible forward, coupled with lower perceived exertion scores (p = 0.04). Mandibular forward repositioning was effective in acutely improving running performance at vV̇o2max with ergogenic effects on ventilatory and perceived variables.

5.
Sensors (Basel) ; 24(18)2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39338777

RESUMO

The effects of occlusal splints on sport performance have already been studied, although their biomechanical impacts are often overlooked. We investigated the kinematical changes during running until exhaustion at severe intensity while wearing a mandibular advancement occlusal splint. Twelve trained runners completed (i) an incremental protocol on a track to determine their velocity corresponding to maximal oxygen uptake and (ii) two trials of square wave transition exercises at their velocity corresponding to maximal oxygen until exhaustion, wearing two occlusal splints (without and with mandibular advancement). Running kinematics were compared within laps performed during the square wave transition exercises and between splint conditions. The mandibular advancement occlusal splint increased the running distance covered (~1663 ± 402 vs. 1540 ± 397 m, p = 0.03), along with a noticeable lap effect in decreasing stride frequency (p = 0.04) and increasing stride length (p = 0.03) and duty factor (p < 0.001). No spatiotemporal differences were observed between splints, except for improved balance foot contact times in the mandibular advancement condition. An increased knee flexion angle at initial contact (p = 0.017) was noted along laps in the non-advancement condition, despite the fact that no differences between splints were found. Running patterns mainly shifted within laps rather than between conditions, indicating that a mandibular advancement occlusal splint had a trivial kinematical effect.


Assuntos
Placas Oclusais , Corrida , Humanos , Masculino , Adulto , Corrida/fisiologia , Fenômenos Biomecânicos/fisiologia , Avanço Mandibular/instrumentação , Avanço Mandibular/métodos , Feminino , Adulto Jovem , Consumo de Oxigênio/fisiologia
6.
Exerc Immunol Rev ; 30: 14-25, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39094179

RESUMO

Skin cancer has the highest incidence of all cancers, and their incidence are increasing in both melanoma and non-melanoma skin cancers. Alternative adjuvant treatment strategies appropriate for their management are needed. Modifiable lifestyle factors influence disease outcomes, either improving or worsening outcomes. Exercise is an example of a modifiable lifestyle factor, and can be prescribed as an adjuvant therapy in other cancer types to improve immune function and overall clinical outcomes. The initial aim of the review was to investigate the T-cell specific mechanisms of exercise which affect clinical/disease outcomes in skin cancer. Study quality was assessed by a modified Covidence quality assessment template with animal-model study specific criteria. A total of 10 articles were included; all articles were murine model studies investigating melanoma. Eight studies (n=8) employed a randomised controlled trial design, with two bio-informatics studies, and one study using human data which could solidify a link to human health. While the review focussed initially on T-cells, many studies reported significant changes in NK cells, and as they share the same haematopoietic lineage/ common lymphoid progenitor as T cells, the data was included in the analyses. Most studies indicated that exercise reduced melanoma tumour burden. Exercising prior to melanoma inoculation was most effective for delaying carcinogenesis and reducing tumour burden. Synergism was a topic identified in studies; PD-1/PD-L1 treatment, and exercise were not synergistic. Conversely, exercise and mental stimulation were synergistic, and the temperature at which exercise was conducted significantly reduced tumour burden. Several murine studies reported that exercise improved clinical outcomes in melanoma, and that long-term exercise was more effective in reducing tumour burden. Further studies are required to investigate this relationship in humans, and in other types of skin cancer.


Assuntos
Exercício Físico , Células Matadoras Naturais , Neoplasias Cutâneas , Linfócitos T , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Humanos , Animais , Células Matadoras Naturais/imunologia , Exercício Físico/fisiologia , Linfócitos T/imunologia , Melanoma/imunologia , Melanoma/terapia , Camundongos , Modelos Animais de Doenças
7.
PLoS One ; 19(6): e0304444, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38941281

RESUMO

To investigate associations between a swimmer's career progression and winning a medal at the Olympic Games (OG) or World Championships (WC). A total of 4631 swimming performances of 1535 top swimmers (653 women, 882 men) from 105 nationalities since1973 were extracted from FINA rankings. A panel of 12 predictor variables including nationality, gender, competition, age, number and timing of competitions, pattern of progressions and regressions in performance, and medal outcomes was established. Linear logistic regression was used to study the association between winning a medal and predictor variables. Logistic regression coefficients were obtained by training on 80% of the database, and prediction accuracy evaluated on the remaining 20%. Using the training set, a selection of 9 most relevant features for prediction of winning a medal (target variable) was obtained through exhaustive feature selection and cross-validation: nationality, competition, number of competitions, number of annual career progressions (nb_prog), maximum annual career progression (max-progr), number of annual career regressions (nb_reg), age at maximum annual progression, P6 (the level of performance six months before the World Championships or Olympic Games), and P2 (the level of performance two months before the World Championships or Olympic Games). A logistic regression model was built and retrained on the entire training set achieved an area under the ROC curve of ~90% on the test set. The odds of winning a medal increased by 1.64 (95% CI, 1.39-1.91) and 1.44 (1.22-1.72) for each unit of increase in max-progr and n-prog, respectively. Odds of winning a medal decreased by 0.60 (0.49-0.72) for a unit increase in n-reg. In contrast, the odds increased by 1.70 (1.39-2.07) and 4.35 (3.48-5.42) for improvements in the 6 and 2 months before competition (P<0.001, for all variables). The likelihood of a swimmer winning an international medal is improved by ~40-90% with progressions from season-to-season, and reducing the number of regressions in performance. The chances of success are also improved 2- to 4-fold by substantial improvements in performance in the months before competition.


Assuntos
Desempenho Atlético , Natação , Humanos , Natação/fisiologia , Masculino , Feminino , Desempenho Atlético/fisiologia , Distinções e Prêmios , Adulto , Modelos Logísticos , Comportamento Competitivo/fisiologia , Atletas
9.
BMC Sports Sci Med Rehabil ; 16(1): 83, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622683

RESUMO

BACKGROUND: For athletes, overcoming obstacles in challenging situations like pandemic home training is crucial. Strategies and approaches in this context are not well-documented. Our study aims to investigate such a scenario from a performance standpoint, based on a major global crisis: the COVID-19 pandemic and lockdown. METHODS: This cross-sectional study surveyed athletes without disabilities using online questionnaires (35 languages) from May to July 2020. Questions included aspects of alternative routines, training monitoring, recovery, sleep patterns, injury occurrence/prevention based on structured answers, and an open-ended question on lockdown training experiences. RESULTS: Of the 11,762 athletes from 142 countries, 63% were male, including at World-Class, International, National, State and Recreational levels. During lockdown, 25% athletes used innovative or modern ways to maintain or improve fitness e.g., virtual reality and tracking devices (favoring World-Class level, 30%). Many athletes, regardless of gender (43%) watched video competitions to improve/maintain their mental skills and performance [World-Class (47%) and International (51%)]. Contact frequency between athletes and their coaches was mainly at least once a week (36%), more among higher-level (World-Class/International) than lower-level athletes (27 vs. 16%). Higher-level athletes (≥ 54%) monitored training load and were assisted by their coaches (21%). During lockdown, stretching (67%) was considered one of the primary means of recovery, especially for higher-level athletes (> 70%). Compared to pre-lockdown, about two-thirds of athletes reported "normal" or "improved" sleep quality and quantity, suggesting a low sleep quality pre-lockdown. On average, 40% utilized injury prevention exercises (at least) once a week [World-Class (51%) and International (39%)]. Most injury occurrences during lockdown involved the knee (18%), ankle (16%), and back (9%). Four key themes emerged regarding lockdown experiences: remote training adaptation (e.g., shifting training focus), training creativity (e.g., using household items), performance enhancement opportunities (e.g., refocusing neglected aspects), and mental and motivation challenges. CONCLUSIONS: Both male and female athletes, particularly those of higher levels, displayed some adaptalibity during the COVID-19 lockdown, employing innovative approaches and technology for training. Many athletes implemented load monitoring, recovery, and attentive of injury prevention, while optimizing their sleep quality and quantity. Athletes demonstrated their abilities to navigate challenges, and utilized different coping strategies in response to the lockdown's constraints.

10.
Sci Rep ; 14(1): 8866, 2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632327

RESUMO

The aim of this study was to investigate relationships between changes in training practices and human development index (HDI) levels, and identify strategies employed by athletes who consistently maintained their training quantity during the first 100 days of the COVID-19 pandemic. A total of 10,074 athletes (5290 amateur and 4787 professional athletes from 121 countries) completed an online survey between 17 May to 5 July 2020. We explored their training practices, including specific questions on training frequency, duration and quantity before and during lockdown (March-June 2020), stratified according to the human development index (HDI): low-medium, high, or very high HDI. During the COVID-19 lockdown, athletes in low-medium HDI countries focused on innovative training. Nevertheless, women and amateur athletes experienced a substantial reduction in training activity. Performance-driven athletes and athletes from higher HDI indexed countries, were likely to have more opportunities to diversify training activities during lockdowns, facilitated by the flexibility to perform training away from home. Factors such as lockdown rules, socioeconomic environment, and training education limited training diversification and approaches, particularly in low-medium and high HDI countries. Athletes (amateurs and professionals) who maintained the quantity of training during lockdown appeared to prioritize basic cardiovascular and strength training, irrespective of HDI level. Modifying training and fitness programs may help mitigate the decrease in training activities during lockdowns. Customized training prescriptions based on gender, performance, and HDI level will assist individuals to effectively perform and maintain training activities during lockdowns, or other challenging (lockdown-like) situations.


Assuntos
COVID-19 , Pandemias , Humanos , Feminino , Controle de Doenças Transmissíveis , Atletas , Exercício Físico
11.
Biol Sport ; 41(2): 221-241, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38524814

RESUMO

The rise of artificial intelligence (AI) applications in healthcare provides new possibilities for personalized health management. AI-based fitness applications are becoming more common, facilitating the opportunity for individualised exercise prescription. However, the use of AI carries the risk of inadequate expert supervision, and the efficacy and validity of such applications have not been thoroughly investigated, particularly in the context of diverse health conditions. The aim of the study was to critically assess the efficacy of exercise prescriptions generated by OpenAI's Generative Pre-Trained Transformer 4 (GPT-4) model for five example patient profiles with diverse health conditions and fitness goals. Our focus was to assess the model's ability to generate exercise prescriptions based on a singular, initial interaction, akin to a typical user experience. The evaluation was conducted by leading experts in the field of exercise prescription. Five distinct scenarios were formulated, each representing a hypothetical individual with a specific health condition and fitness objective. Upon receiving details of each individual, the GPT-4 model was tasked with generating a 30-day exercise program. These AI-derived exercise programs were subsequently subjected to a thorough evaluation by experts in exercise prescription. The evaluation encompassed adherence to established principles of frequency, intensity, time, and exercise type; integration of perceived exertion levels; consideration for medication intake and the respective medical condition; and the extent of program individualization tailored to each hypothetical profile. The AI model could create general safety-conscious exercise programs for various scenarios. However, the AI-generated exercise prescriptions lacked precision in addressing individual health conditions and goals, often prioritizing excessive safety over the effectiveness of training. The AI-based approach aimed to ensure patient improvement through gradual increases in training load and intensity, but the model's potential to fine-tune its recommendations through ongoing interaction was not fully satisfying. AI technologies, in their current state, can serve as supplemental tools in exercise prescription, particularly in enhancing accessibility for individuals unable to access, often costly, professional advice. However, AI technologies are not yet recommended as a substitute for personalized, progressive, and health condition-specific prescriptions provided by healthcare and fitness professionals. Further research is needed to explore more interactive use of AI models and integration of real-time physiological feedback.

12.
Int J Sports Physiol Perform ; 19(3): 299-306, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38194958

RESUMO

PURPOSE: Fran is one of the most popular CrossFit benchmark workouts used to control CrossFitters' improvements. Detailed physiological characterization of Fran is needed for a more specific evaluation of CrossFitters' training performance improvements. The aim of the study was to analyze the oxygen uptake (V˙O2) kinetics and characterize the energy system contributions and the degree of postexercise fatigue of the unbroken Fran. METHODS: Twenty trained CrossFitters performed Fran at maximal exertion. V˙O2 and heart-rate kinetics were assessed at baseline and during and post-Fran. Blood lactate and glucose concentrations and muscular fatigue were measured at baseline and in the recovery period. RESULTS: A marked increase in V˙O2 kinetics was observed at the beginning of Fran, remaining elevated until the end (V˙O2peak: 49.2 [3.7] mL·kg-1·min-1, V˙O2 amplitude: 35.8 [5.2] mL·kg-1·min-1, time delay: 4.7 [2.5] s and time constant: 23.7 [11.1] s; mean [SD]). Aerobic, anaerobic lactic, and alactic pathways accounted for 62% (4%), 26% (4%), and 12% (2%) of energy contribution. Reduction in muscle function in jumping ability (jump height: 8% [6%], peak force: 6% [4%], and maximum velocity: 4% [2%]) and plank prone test (46% [20%]) was observed in the recovery period. CONCLUSIONS: The Fran unbroken workout is a high-intensity effort associated with an elevated metabolic response. This pattern of energy response highlights the primary contribution of aerobic energy metabolism, even during short and very intense CrossFit workouts, and that recovery can take >24 hours due to cumulative fatigue.


Assuntos
Fadiga , Consumo de Oxigênio , Humanos , Consumo de Oxigênio/fisiologia , Fadiga Muscular/fisiologia , Oxigênio , Músculos
13.
Sensors (Basel) ; 24(2)2024 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-38257605

RESUMO

Our purpose was to characterize the oxygen uptake kinetics (VO2), energy systems contributions and total energy expenditure during a CrossFit® benchmark workout performed in the extreme intensity domain. Fourteen highly trained male CrossFitters, aged 28.3 ± 5.4 years, with height 177.8 ± 9.4 cm, body mass 87.9 ± 10.5 kg and 5.6 ± 1.8 years of training experience, performed the Isabel workout at maximal exertion. Cardiorespiratory variables were measured at baseline, during exercise and the recovery period, with blood lactate and glucose concentrations, including the ratings of perceived exertion, measured pre- and post-workout. The Isabel workout was 117 ± 10 s in duration and the VO2 peak was 47.2 ± 4.7 mL·kg-1·min-1, the primary component amplitude was 42.0 ± 6.0 mL·kg-1·min-1, the time delay was 4.3 ± 2.2 s and the time constant was 14.2 ± 6.0 s. The accumulated VO2 (0.6 ± 0.1 vs. 4.8 ± 1.0 L·min-1) value post-workout increased substantially when compared to baseline. Oxidative phosphorylation (40%), glycolytic (45%) and phosphagen (15%) pathways contributed to the 245 ± 25 kJ total energy expenditure. Despite the short ~2 min duration of the Isabel workout, the oxygen-dependent and oxygen-independent metabolism energy contributions to the total metabolic energy release were similar. The CrossFit® Isabel requires maximal effort and the pattern of physiological demands identifies this as a highly intensive and effective workout for developing fitness and conditioning for sports.


Assuntos
Benchmarking , Metabolismo Energético , Masculino , Humanos , Cinética , Exercício Físico , Oxigênio
15.
J Hum Kinet ; 89: 161-169, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38053969

RESUMO

Swimming performance achieved in 50-m, 100-m and 200-m events in each swimming stroke can have an influence on the final performance in individual medley (IM) events. We attempted to quantify the relative contributions of performance in individual stroke events to top-10 world ranked IM competition performance. We examined competition results of top-10 world ranked IM swimmers (90 males and 90 females) between 2012 and 2018. A general linear model was developed to examine association between the 200-m and 400-mIM and predictor variables of competition performance in other 50-m, 100-m, and 200-m events. The main predictor variable for 200-mIM medalist status was having scored more than 900 FINA points in at least one 100-m event. Scoring more than 800 FINA points in at least two 200-mIM events, and more than 900 FINA points in at least one 100-m event, was important for success in the 400-mIM. Top-10 world ranked 200-mIM and 400-mIM swimmers require a world class standard in one or more individual stroke event(s).

16.
PeerJ ; 11: e16612, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38111656

RESUMO

Objectives: The relative contribution of each of the four strokes to performance, and whether these contributions differ substantially between short course and long course competitions is unclear. To clarify these issues the aim of this study was to assess the strokes that have more influence on the performance in the 200 and 400 m IM swimming performances of elite male and female swimmers, participating in major events: Olympic Games (OG) and World Championship (WC) in short-course and long-course from 2012 to 2021. Methods: Data from 1,095 swimmers (501 women and 594 men) who competed in 200 and 400-m IM were obtained with a minimum level of 800 FINA points. Linear regression modelling and classification trees were employed to quantify differences between strokes and short/long course swimming. Results: Regression analysis indicated that breaststroke (ß =  - 0.191; p < 0.000) and backstroke (ß =  - 0.185; p < 0.000) had a bigger effect on IM performance, with butterfly (ß =  - 0.101; p < 0.000) having a lesser impact. The classification trees showed threshold performance standards in terms of 50-m times in form-stroke events must be fulfilled to attain medal-winning performances. Conclusions: These form-stroke standards represent important milestones for designing medal-oriented training strategies for both 200 IM and 400 m IM. Achieving a medallist position in 200 and 400 m IM requires obtaining specified lap times in butterfly, breaststroke and backstroke for males and females in long-course competitions, and breaststroke and backstroke for short-course competitions. The OG presents more exigent demands of lap times in butterfly, crawl and backstroke for IM swimmers.


Assuntos
Desempenho Atlético , Natação , Masculino , Humanos , Feminino , Comportamento Competitivo , Análise de Regressão , Modelos Lineares
17.
J Sports Sci Med ; 22(3): 571-581, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37711705

RESUMO

The objective of this research was to compare technical skills composed of kinematic and kinetic variables in the complex motor task of a tumble turn between 9 elites and 9 sub-elite female swimmers. The best tumble turn among three attempts was analyzed using a three-dimensional underwater protocol. A total of 37 kinematic variables were derived from a Direct Linear Transformation algorithm for 3D reconstruction, and 16 kinetic variables measured by a piezoelectric 3D force platform. Data were analyzed by Student's t-test and effect size statistics. Pearson correlations were applied to the data of the eighteen swimmers to relate the association of 53 kinematic, kinetic variables to the performance of the tumble-turn (3 meters Round Trip Time, 3m RTT). The approach and the whole turn times were faster for elite swimmers compared to sub elites (1.09±0.06 vs. 1.23±0.08 sec, and 2.89±0.07 vs. 3.15±0.11 sec.), as well as the horizontal speeds of the swimmers' head 1 m before the rotation (1.73±0.13 vs. 1.57±0.13 m/sec.), at the end of the push-off on force platform (2.55±0.15 vs. 2.31±0.22 m/sec.) and 3 m after the wall (2.01±0.19 vs. 1.68±0.12 m/sec.). Large differences (|d| > 0.8) in favor of the elite swimmers were identified for the index of upper body extension at the beginning of the push-off, the lower limb extension index at the end of push-off, and among the kinetic variables, the horizontal impulse and lateralization of the push-off. Correlations for the whole group revealed a moderate to strong relationship between 6 body extension indices and 3mRTT performance. For the kinetic variables, the correlations indicated the fastest swimmers in 3mRTT showed large lateral impulse during placement (r=0.46), maximum horizontal force during the push-off (r=0.45) and lateralization of the push-off (r=0.44) (all p<0.05). Elite female swimmers had higher approach and push-off speeds, were more streamlined through the contact, and showed a higher horizontal impulse and lateralization of the push-off, than their sub-elite counterparts.


Assuntos
Algoritmos , Extremidade Inferior , Humanos , Feminino , Cinética , Rotação
18.
Int J Sports Physiol Perform ; 18(9): 1085-1088, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37573027

RESUMO

PURPOSE: As the start of the 10th Rugby Union World Cup approaches, performance staff will be working on the final elements of their teams' preparation. Much of this planning and preparation will be underpinned by the latest performance science research. In this invited commentary, we discuss contemporary performance science research in rugby union centered around 4 key performance domains. First, we outline a systematic approach to developing an overall understanding of the game demands and how performance staff can enhance the players' preparedness for competition. We then move on to outline our understanding of the training science domain, followed by a brief overview of effective recovery strategies at major tournaments. Finally, we outline research in the area of competition-day strategies and how they can positively impact players' readiness to compete. CONCLUSIONS: Evaluating a team's preparation for the Rugby Union World Cup can be achieved by mapping their performance plan based on the 4 domains outlined above.


Assuntos
Rugby , Humanos
19.
Int J Sports Physiol Perform ; 18(9): 1072-1078, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37597840

RESUMO

PURPOSE: The efficacy of isolated and relative performance indicators (PIs) has been compared in rugby union; the latter more effective at discerning match outcomes. However, this methodology has not been applied in women's rugby. The aim of this study was to identify PIs that maximize prediction accuracy of match outcome, from isolated and relative data sets, in women's rugby union. METHODS: Twenty-six PIs were selected from 110 women's international rugby matches between 2017 and 2022 to form an isolated data set, with relative data sets determined by subtracting corresponding opposition PIs. Random forest classification was completed on both data sets, and feature selection and importance were used to simplify models and interpret key PIs. Models were used in prediction on the 2021 World Cup to evaluate performance on unseen data. RESULTS: The isolated full model correctly classified 75% of outcomes (CI, 65%-82%), whereas the relative full model correctly classified 78% (CI, 69%-86%). Reduced respective models correctly classified 74% (CI, 65%-82%) and 76% (CI, 67%-84%). Reduced models correctly predicted 100% and 96% of outcomes for isolated and relative test data sets, respectively. No significant difference in accuracy was found between data sets. In the relative reduced model, meters made, clean breaks, missed tackles, lineouts lost, carries, and kicks from hand were significant. CONCLUSIONS: Increased relative meters made, clean breaks, carries, and kicks from hand and decreased relative missed tackles and lineouts lost were associated with success. This information can be utilized to inform physical and tactical preparation and direct physiological studies in women's rugby.


Assuntos
Rugby , Extremidade Superior , Humanos , Feminino , Algoritmo Florestas Aleatórias
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