physiological demands
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2022 ◽  
Vol 18 (67) ◽  
pp. 15-28
Author(s):  
Randall Gutiérrez-Vargas ◽  
José Pino-Ortega ◽  
Alexis Ugalde-Ramírez ◽  
Braulio Sánchez-Ureña ◽  
Luis Blanco-Romero ◽  
...  

This study aimed to compare physical and physiological demands in youth basketball players according to gender, playing positions, and match outcomes. 64 players (32 female and 32 male) from eight youth sub-elite basketball teams were monitored using an Ultra-Wide Band system and inertial measurement unit in three consecutive matches. The results showed some significant differences, although with magnitudes qualified as small. When the teams won, the guards covered a greater distance at 0-6 km/h than when they lost. When teams lost, the centers covered more distance at 12-18 km/h and 18-21 km/h. The winning female teams presented a lower maximal heart rate (HRmax) compared to the losing teams. The forwards of the winning teams performed greater efforts at 70-80% HRmax, while the forwards of losing teams performed more efforts at 90-95% HRmax. The greatest number of accelerations and decelerations were performed by the female guards and the male forwards. The number of jumps was higher in the male guards and forwards than in the female ones. HRmax was higher in the forwards of the female teams. Efforts at 80%-90% HRmax were higher in male centers. When the female teams won, they had a lower HRmax than when they lost. When efforts exceed 90% of HRmax the teams lost. In conclusion, despite the differences found, the effect of these contextual variables on physical and physiological demands is unclear. Nevertheless, knowing the game's requirements can help the design of training that enhances the performance of youth basketball players


2021 ◽  
Vol 11 (22) ◽  
pp. 10658
Author(s):  
Alan Ruddock ◽  
Lachlan James ◽  
Duncan French ◽  
David Rogerson ◽  
Matthew Driller ◽  
...  

Combat sports have been practiced for millennia and today are predominant sports at the Olympic games, with international organizations that host world, continental and national championships at amateur standard. There are also an increasing number of professional combat sports with global audiences. The growing popularity of professional combat sports and their importance at the Olympic games have led to an increase in scientific studies that characterize the physical, physiological, nutritional, biomechanical and training strategies of combat sports athletes. These studies characterize combat sports as high-intensity sports which require training strategies to develop the high-intensity capabilities of athletes. Therefore, the aim of this article is to (i) summarize the physiological demands of combat sports; (ii) present the primary considerations required to program high-intensity conditioning for athletes; (iii) define and present key high-intensity conditioning methods; and (iv) provide guidance for scientists and coaches to help prepare athletes under common but differing circumstances.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Youngshin Lim ◽  
Il-Taeg Cho ◽  
Helmut G. Rennke ◽  
Ginam Cho

AbstractInteractions between the endoplasmic reticulum (ER) and mitochondria (Mito) are crucial for many cellular functions, and their interaction levels change dynamically depending on the cellular environment. Little is known about how the interactions between these organelles are regulated within the cell. Here we screened a compound library to identify chemical modulators for ER-Mito contacts in HEK293T cells. Multiple agonists of G-protein coupled receptors (GPCRs), beta-adrenergic receptors (β-ARs) in particular, scored in this screen. Analyses in multiple orthogonal assays validated that β2-AR activation promotes physical and functional interactions between the two organelles. Furthermore, we have elucidated potential downstream effectors mediating β2-AR-induced ER-Mito contacts. Together our study identifies β2-AR signaling as an important regulatory pathway for ER-Mito coupling and highlights the role of these contacts in responding to physiological demands or stresses.


2021 ◽  
Author(s):  
Étienne Chassé ◽  
Daniel Théoret ◽  
Martin P Poirier ◽  
François Lalonde

ABSTRACT Introduction Members of the Canadian Armed Forces (CAF) are required to meet the minimum standards of the Fitness for Operational Requirements of CAF Employment (FORCE) job-based simulation test (JBST) and must possess the capacity to perform other common essential tasks. One of those tasks is to perform basic fire management tasks during fire emergencies to mitigate damage and reduce the risk of injuries and/or death until professional firefighters arrive at the scene. To date however, the physiological demands of common firefighting tasks have mostly been performed on professional firefighters, thus rendering the transferability of the demands to the general military population unclear. This pilot study aimed to quantify, for the first time, the physiological demands of basic fire management tasks in the military, to determine if they are reflected in the FORCE JBST minimum standard. We hypothesized that the physiological demands of basic fire management tasks within the CAF are below the physiological demands of the FORCE JBST minimum standard, and as such, be lower than the demands of professional firefighting. Materials and methods To achieve this, 21 CAF members (8 females; 13 males; mean [SD] age: 33 [10] years; height: 174.5 [10.5] cm; weight: 85.4 [22.1] kg, estimated maximal oxygen uptake [$\dot V$O2peak]: 44.4 (7.4) mL kg−1 min−1) participated in a realistic, but physically demanding, JBST developed by CAF professional firefighting subject matter experts. The actions included lifting, carrying, and manipulating a 13-kg powder fire extinguisher and connecting, coupling, and dragging a 38-mm fire hose over 30 m. The rate of oxygen uptake ($\dot V$O2), heart rate, and percentage of heart rate reserve were measured continuously during two task simulation trials, which were interspersed by a recovery period. Rating of perceived exertion (6-no exertion; 20-maximal exertion) was measured upon completion of both task simulations. Peak $\dot V$O2 ($\dot V$O2peak) was estimated based on the results of the FORCE JBST. Results The mean (SD) duration of both task simulation trials was 3:39 (0:19) min:s, whereas the rest period in between both trials was 62 (19) minutes. The mean O2 was 21.1 (4.7) mL kg−1 min−1 across trials, which represented 52.1 (12.2) %$\dot V$O2peak and ∼81% of the FORCE JBST. This was paralleled by a mean heart rate of 136 (18) beats min−1, mean percentage of heart rate reserve of 61.2 (10.8), and mean rating of perceived exertion of 11 ± 2. Other physical components of the JBST consisted of lifting, carrying, and manipulating a 13-kg load for ∼59 seconds, which represents 65% of the load of the FORCE JBST. The external resistance of the fire hose drag portion increased up to 316 N, translating to a total of 6205 N over 30 m, which represents 96% of the drag force measured during the FORCE JBST. Conclusions Our findings demonstrate that the physiological demands of basic fire management tasks in the CAF are of moderate intensity, which are reflected in the CAF physical fitness standard. As such, CAF members who achieve the minimum standard on the FORCE JBST are deemed capable of physically performing basic fire management tasks during fire emergencies.


2021 ◽  
Vol 25 ◽  
pp. e1029
Author(s):  
Raúl Domínguez ◽  
Antonio Jesús Sánchez Oliver ◽  
Sandro Fernandes da Silva ◽  
Alvaro López-Samanes ◽  
José Miguel Martínez-Sanz ◽  
...  

Introduction: Tennis is characterized by a large number of competitions and little recovery time between them. Thus, tennis players and coaching staff have become interested in the role that nutrition can play in maximizing sports performance. The scientific literature does not have recent narrative and/or systematic reviews about to nutrition in tennis. The aim of this study is to map, describe and discuss the state of the science of nutrition and dietetic practices for tennis players from a theoretical and contextual point of view, to enable focused future systematic reviews.Material and methods: A narrative review through the Dialnet, Elsevier, Medline, Pubmed and Web of Science databases, through a search strategy based on keywords separated by Boolean connectors. A series of inclusion / exclusion criteria were applied to select those investigations that responded to the aim of the work.Results: Nutritional recommendations on carbohydrate intake depend on the training load, 5-7 g/kg/day g/kg/day for normal training and 7-10 g/kg/day for competitive periods or high training load. The recommended protein intake is 1.8 g/kg/day and 1 g/kg/day of lipids. The supplements that can optimize tennis performance are caffeine, sodium bicarbonate, creatine and β-alanine. Beetroot juice can be a possible aid to consider in dietetic-nutritional planning in tennis players.Conclusions: Performance and health of tennis player can be optimized, as well as adequate periodization of nutrients and supplements, meeting to the physiological demands of tennis.


Author(s):  
Satendra Kumar Verma ◽  
Sunil Kumar D. ◽  
Rufia Shaistha Khanum ◽  
Narayanmurthy M. R.

Background: Anemia is the commonest micronutrient deficiency across the world. The burden of disease is high in underdeveloped and developing countries. Anemia itself is not a disease but a symptom of underlying deficiency. A large portion of iron deficiency is preventable with appropriate and timely intervention. Adolescence is a crucial phase for growth and development. Increased physiological demands, poor attitude of young children towards nutrition, lack of awareness amongst parents about healthy diet etc., are some of the reasons that makes anemia common among adolescents.Methods: A cross-sectional study was conducted in JSS schools and pre-university during February 2021. Sample size is 292 and a total of 300 girls in late adolescent age group were included in the study. Haemoglobin estimation was done by finger prick method using a digital haemoglobinometer. A structured proforma was used to collect data regarding socio-demographic characteristics and factors associated with anemia.Results: In our study 49% of the girls were anemic. Mean haemoglobin levels of the girls were 14±4 mg/dl. In this study there was significant association between menarche status (p=0.0041) and history of taking iron supplements (p=0.04). Significant association was noted between the mother’s education and the study participants’ anemia status (p=0.00). Significant association was noticed between BMI category of the study participants and their anemia status (p<2.2e-16).Conclusions: Anemia is huge problem among adolescent girls. The awareness is poor regarding the disease and its effects. The community is ignorant about the detrimental effects of anemia. Hence appropriate health interventions targeting women and children are needed to see any positive changes in their status.


2021 ◽  
Author(s):  
Helena Batatinha ◽  
Forrest L. Baker ◽  
Kyle A. Smith ◽  
Tiffany M. Zúñiga ◽  
Charles R. Pedlar ◽  
...  

AbstractAthletes are advised to receive the COVID-19 vaccination to protect them from SARS CoV-2 infection during major competitions. Despite this, many athletes are reluctant to get the COVID-19 vaccine due to concerns that symptoms of vaccinosis may impair athletic performance.OBJECTIVETo determine the effects of COVID-19 vaccination on the physiological responses to graded exercise.METHODSHealthy participants completed a 20-minute bout of graded cycling exercise before and ~21 days after COVID-19 vaccination (2 dose Pfizer mRNA or 1 dose Johnson & Johnson).RESULTSOxygen uptake, CO2 production, respiratory exchange ratio, ventilation, heart rate, serum noradrenaline, and rating of perceived exertion were significantly elevated in the post vaccine trial. However, vaccination did not affect serum lactate, adrenaline, cortisol, predicted , and ventilatory threshold. Post-vaccine effects on heart rate and noradrenaline remained significant in non-infected participants that received the Pfizer vaccine. No significant effects in respiratory gas exchange parameters were found after vaccination in those previously exposed to SARS-CoV-2, but exercise adrenaline levels were significantly lower and serum lactate levels trending (p= 0.10) lower after vaccination. No changes in any physiological responses to exercise were found in control participants who completed two bouts of exercise separated by ~5 weeks without vaccination.CONCLUSIONRecent COVID-19 vaccination is associated with modest increases in the physiological demands to graded exercise in non-infected healthy people but may actually improve metabolic responses to exercise in those previously infected with SARS-CoV-2. Whether or not these small effects could impact athletic performance at the elite level warrants investigation.


Author(s):  
Jens Heyn ◽  
Johannes Fleckenstein

Abstract Background Handball referees play an important role during a handball match. Surprisingly, not much is known about their sports-related injuries and resulting pain, therefore the purpose of our study was to focus on injuries and sports-related pain in referees in German handball leagues. Methods During the 2018/19 national German handball season, referees of the German Federation of Handball (DHB) were contacted and asked to complete an injury and pain questionnaire on the penultimate matchday of the first and the second round of the season. Results Seventy referees participated in the study. One in three referees reported an injury during the last year and perceived some form of pain. Of those suffering from pain, 16.7% referees reported chronic pain disorders. During the season, 31.4% of referees incurred an injury and the majority of the 70 referees officiated despite pain (n = 43). Prospectively-enrolled data suggested an incidence of 11.6 (95% CI: 10.3 to 13.0) injuries per 1000 match hours, and 19.0 (95% CI: 16.8 to 21.3) sports-related pain events per 1000 match hours. The most common injuries were foot and knee injuries and a substantial number of the referees (n = 25) reported taking analgesics for the pain. Conclusion German handball referees are at risk of sports-related injuries with subsequent pain. Considering the injury profile, the incidence of sports-related pain events, and the high physiological demands of refereeing, it appears that prevention programs should be developed and integrated into the routine of the referee.


Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5242
Author(s):  
Jolene Ziyuan Lim ◽  
Alexiaa Sim ◽  
Pui Wah Kong

The aim of this review is to investigate the common wearable devices currently used in field hockey competitions, and to understand the hockey-specific parameters these devices measure. A systematic search was conducted by using three electronic databases and search terms that included field hockey, wearables, accelerometers, inertial sensors, global positioning system (GPS), heart rate monitors, load, performance analysis, player activity profiles, and competitions from the earliest record. The review included 39 studies that used wearable devices during competitions. GPS units were found to be the most common wearable in elite field hockey competitions, followed by heart rate monitors. Wearables in field hockey are mostly used to measure player activity profiles and physiological demands. Inconsistencies in sampling rates and performance bands make comparisons between studies challenging. Nonetheless, this review demonstrated that wearable devices are being used for various applications in field hockey. Researchers, engineers, coaches, and sport scientists can consider using GPS units of higher sampling rates, as well as including additional variables such as skin temperatures and injury associations, to provide a more thorough evaluation of players’ physical and physiological performances. Future work should include goalkeepers and non-elite players who are less studied in the current literature.


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