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2.
Physiol Behav ; 269: 114284, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37394051

RESUMEN

INTRODUCTION: Prolonged exercise has been linked to a decline in cognitive function due to a variety of factors, such as a drop in oxygen in the prefrontal cortex and an increase in stress hormones and neurotransmitters. Medium chain triglycerides (MCTs) may possibly offset this decline as they provide energy for the brain via both direct and indirect pathways, alongside promoting chronic physiological adaptations within the brain. METHODS: Participants were divided into two groups; MCT (n = 9) and Placebo (n = 10). The MCT gels contained 6 g of MCT with a C8:C10 ratio of 30:70, whereas the placebo gels contained carbohydrates of similar calorific value to the MCT gels. Participants visited the laboratory on three occasions (familiarisation/fitness test, pre-supplementation, post-supplementation), during which they performed a battery of cognitive tasks assessing domains such as processing speed, working memory, selective attention, decision making and coordination, before and after a prolonged bout of exercise (60 mins at 90% gas exchange threshold (GET). A 2-week supplementation period between visits 2 and 3 involved the ingestion of 2 gels per day. RESULTS: Exercise resulted in detriments in most cognitive tasks pre-supplementation for both groups, and post-supplementation for the Placebo group (main effect ps< 0.05). Post-supplementation, the effect of exercise was mediated in the MCT group for all cognitive tasks (main effect ps< 0.05), except for the Digit and Spatial Span Backwards test phases (main effect ps> 0.05). Furthermore, MCT supplementation enhanced before-exercise cognitive performance and in some measures, such as working memory, this was maintained after-exercise (interaction effect ps> 0.05). CONCLUSIONS: Chronic MCT supplementation enhanced before-exercise cognitive performance and offset the cognitive decline caused by a prolonged bout of exercise. In some cases, improvements in before-exercise cognitive performance were maintained after-exercise.


Asunto(s)
Disfunción Cognitiva , Ejercicio Físico , Adulto , Humanos , Cognición , Ejercicio Físico/fisiología , Geles , Triglicéridos/metabolismo
3.
Biol Sport ; 40(2): 457-464, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37077788

RESUMEN

Submission grappling consists of skills and movements used in combat sports to physically control opponents whilst trying to apply choke holds and joint locks. There is currently no accepted method of monitoring external load in grappling-based sports due to the absence of key variables such as distance, velocity or time. The primary aim of this study was to determine whether PlayerLoad is a reliable variable for measuring external load of submission grappling movements, with a secondary aim of determining the between repetition variance of submission grappling movements. 7 experienced submission grapplers were recruited. Each wore a torso mounted Catapult® Optimeye S5 microelectromechanical systems (MEMS) device and completed 5 repetitions of each of the following: 4 submission techniques; 5 transition techniques; 2 guard pass techniques; 2 takedown techniques. Accumulated PlayerLoad (PLdACC) was recorded as a marker of absolute load, with accumulated PlayerLoad per minute (PLdACC∙min-1) representing relative load. Reliability of each was assessed using intraclass correlation coefficient (ICC(3,1)) (≥ 0.70). Between repetition movement variation was assessed via coefficient of variation with 95% confidence intervals (CV, 95%CI) (acceptable ≤ 15%, good ≤ 10%). PLdACC ICC(3,1) range = 0.78-0.98, with CV range = 9-22%. PLdACC∙min-1 ICC(3,1) range = 0.83-0.98, with CV range = 11-19%. Though several variables displayed CV > 15%, all had 95%CI lower boundaries ≤ 15%. Whilst PlayerLoad was found to be a reliable measure for submission grappling, relatively high CVs across most techniques examined suggest PlayerLoad may not be appropriate for measuring changes in external load for individual movements in submission grappling. However, it may prove a useful tool for monitoring the external load of full, grappling-based, training sessions within an individual.

4.
BMC Sports Sci Med Rehabil ; 14(1): 179, 2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36217163

RESUMEN

BACKGROUND: To clarify does physical performance affect success in highest-level soccer, the purpose of the present study was to identify differences in technical-tactical performance (TP) between teams covering high and low running performance (RP) during the UEFA Champions League (UCL) matches. METHODS: The RP and TP data were collected from UCL group stage matches in the 2020/21 season. RP variables included total distance covered (TD), high intensity running (HIR), total distance when in ball possession (TDB), and high intensity running when in ball possession (HIRB). TP variables included goal chances, shots, shots on target, passes, accurate passes, key passes, key passes accurate, crosses, crosses accurate, counter attacks, counter attacks with a shot, high pressing, high pressing successful, low pressing, low pressing successful, tackles, tackles successful, entrances to the opponent's box, total actions, and successful actions. K-means cluster analysis method was used to classify teams covering (i) low and high TD, (ii) low and high HIR, (iii) low and high TDB, (iv) low and high and HIRB. Linear mixed models were used to identify differences in teams' TP according to their RP. Pearson's correlations were used to establish direct association between team TP and RP. RESULTS: Similar TP were observed whether teams covering high or low TD/HIR. Teams covering greater TDB/HIRB had more goal chances, shots, shots on target, passes, accurate passes, key passes, accurate key passes, crosses, successful high pressing, entrances to the opponent's box, total actions, and successful actions were observed (all moderate to very large effect sizes. Significant association between specific TP variables and TDB/HIRB were evidenced (Pearson's r = 0.35-0.96, all p < 0.05). CONCLUSION: Covering greater TDB and HIRB may allow more frequent execution of fundamental TP which are considered essential for match success, indicating that RP when team has ball in possession is important determinant of success in highest-level soccer. This study shows that physical performance affect success in highest-level soccer.

5.
Nutrients ; 14(3)2022 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-35277016

RESUMEN

Soccer is a high intensity intermittent sport, featuring critical events completed at high/maximal intensity which is superimposed onto an aerobic base of lower intensity activities and rest. Due to these varying energic demands and the duration of competition the need for optimal nutritional strategies to offset and delay fatigue are paramount. Over the last 50 years, several investigations have been reported on aspects of soccer be they nutrition-focused or those concerning the demands of the sport. Emanating from these scientific papers, observations have been made on the likely factors which result in the fatigue during match-play. Factors such as muscle glycogen depletion and hypoglycaemia are discussed. Studies on the energy demands of soccer have employed a variety of methodologies which are briefly reviewed and vary between the use of heart rate telemetry to the use of global positioning systems (GPS). Moving on from observations of the energy demands of the sport leads to the major focus of this review which highlights key nutritional strategies to support the preparation and recovery of male soccer players to enhance performance, or at least to enable players to perform adequately. This review examines relevant methodologies in assessing training and competitive energy costs as well as the concomitant energy intakes demanded for successful performance outcomes. In order to bring an applied aspect to the overall findings from areas discussed, some practical ideas of feeding strategies are presented.


Asunto(s)
Fútbol , Ingestión de Energía , Fatiga , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Necesidades Nutricionales , Fútbol/fisiología
6.
Sci Med Footb ; 6(1): 1-6, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35236222

RESUMEN

This study assessed the interchangeability between 10-Hz multi-GNSS GPS devices (Vector®) and two optical tracking systems (TRACAB® and Second Spectrum®). The agreement between data from the optical tracking systems when processed with manufacturer and GPS-filtered software was also assessed. Thirty players competing in the English Premier League were monitored using three different tracking systems across five matches. To determine the interchangeability between systems, player movement variables including, total distance, high-speed running distance (19.8-25.2 km·h-1), sprinting distance (>25.2 km·h-1), efforts >19.8 km·h-1 and maximal speed were compared. Equations were formed using linear regression and linear mixed-effects models to allow interchangeability of player movement variables between systems. Over half of the variance of most interchangeability equations were explained and associated with very strong positive correlations (r > 0.72). Small to huge differences were found between systems for most player movement variables. Data of optical tracking systems had decreased values in speed variables >19.8 km·h-1 when processed through GPS software. This study provides equations for practitioners to interchange player movement variables between TRACAB, Second Spectrum and Vector GPS systems with reduced error. This will enable practitioners to combine and share data captured with different tracking systems to analyse and improve their training.


Asunto(s)
Rendimiento Atlético , Carrera , Fútbol , Atletas , Humanos , Movimiento
7.
Biol Sport ; 39(1): 31-36, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35173360

RESUMEN

The use of whole-body cryotherapy (WBC) as a recovery intervention is prevalent amongst elite soccer players. However, there is a distinct lack of data available around chronic WBC use and post-match recovery markers in elite soccer. The aim of this study was to investigate the impact of different levels of WBC exposure on subjective and objective measures of post-match recovery in elite soccer players during a chronic exposure period. Sixteen male senior professional outfield soccer players participated in this study over two seasons. K means cluster analysis was used to classify low (-114 ± 2°C for 133 ± 2 s), medium (-121 ± 1°C for 173 ± 2 s) and high (-133 ± 1°C for 181 ± 2 s) cryotherapy exposure indexes (CEI). Salivary markers (immunoglobulin A (IgA) and alpha amylase (AA)) and subjective wellness scores (perceived fatigue, sleep quality, general muscle soreness and stress) were collected post-match across both seasons. Training load (session-RPE) was collected and used as a covariate to control for the load amongst groups. No differences were seen in perceived measures of wellness and salivary AA. Significantly lower IgA concentrations were observed in the medium CEI group (255 ± 32 µg∙ml-1) compared to the low (328 ± 38 µg∙ml-1) and high (306 ± 32 µg∙ml-1) groups. Therefore, increasing the level of chronic WBC exposure appears to have no additional benefit on subjective recovery and alpha amylase response post-match. However, there appears to be an optimal chronic WBC dose with regards to IgA response.

8.
Eur J Appl Physiol ; 121(5): 1255-1269, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33544230

RESUMEN

PURPOSE: Carbohydrates (CHO) are one of the fundamental energy sources during prolonged steady state and intermittent exercise. The consumption of exogenous CHO during exercise is common place, with the aim to enhance sporting performance. Despite the popularity around exogenous CHO use, the process by which CHO is regulated from intake to its use in the working muscle is still not fully appreciated. Recent studies utilizing the hyperglycaemic glucose clamp technique have shed light on some of the potential barriers to CHO utilisation during exercise. The present review addresses the role of exogenous CHO utilisation during exercise, with a focus on potential mechanisms involved, from glucose uptake to glucose delivery and oxidation at the different stages of regulation. METHODS: Narrative review. RESULTS: A number of potential barriers were identified, including gastric emptying, intestinal absorption, blood flow (splanchnic and muscle), muscle uptake and oxidation. The relocation of glucose transporters plays a key role in the regulation of CHO, particularly in epithelial cells and subsequent transport into the blood. Limitations are also apparent when CHO is infused, particularly with regards to blood flow and uptake within the muscle. CONCLUSION: We highlight a number of potential barriers involved with the regulation of both ingested and infused CHO during exercise. Future work on the influence of longitudinal training within the regulation processes (such as the gut) is warranted to further understand the optimal type, dose and method of CHO delivery to enhance sporting performance.


Asunto(s)
Metabolismo de los Hidratos de Carbono/fisiología , Carbohidratos de la Dieta/farmacología , Ejercicio Físico/fisiología , Músculo Esquelético/metabolismo , Carbohidratos de la Dieta/administración & dosificación , Vaciamiento Gástrico/fisiología , Glucosa/metabolismo , Glucógeno/metabolismo , Humanos , Absorción Intestinal/fisiología , Oxidación-Reducción , Flujo Sanguíneo Regional/fisiología
9.
Sci Med Footb ; 5(3): 181-187, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-35077295

RESUMEN

Purpose: There isgrowing concern surrounding the harmful effects of soccer heading on cognitive function. The present study aims to examine the immediate effects of heading.Methods: 30 recreational male soccer players were divided into three groups that undertook 20 consecutive headers with a soft (8.8 psi), hard (16.2 psi), or no (control) ball. A battery of neuropsychological tests was completed before and after heading: King-Devick, trail-making (TM) (A, B), digit span (DS) and spatial span (SS) (forward, backward).Results: Significant increase in the time (M = 4.44 s) and errors (M = 1.45) for the King-Devick test within the hard and soft groups, although there was no significant difference for TM-A and TM-B. Significant decline for SS forward within the hard and soft groups (M= -16%), although the declines for SS backward (M = -16%), DS forward (M= -23%) and DS backward (M = -25%) were present only for the hard group (ps <.05).Discussion: While outside of regular match-play, this study showed that heading negatively influenced one indicator of a suspected concussion (King-Devick), as well as working memory (DS, SS) that is essential for daily life. These findings contribute to the growing debate surrounding heading safety.


Asunto(s)
Conmoción Encefálica , Fútbol , Conmoción Encefálica/diagnóstico , Cognición , Humanos , Masculino , Memoria a Corto Plazo , Pruebas Neuropsicológicas
10.
J Sport Health Sci ; 10(4): 403-412, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-32961300

RESUMEN

Biological maturation can be defined as the timing and tempo of progress to achieving a mature state. The estimation of age of peak height velocity (PHV) or percentage of final estimated adult stature attainment (%EASA) is typically used to inform the training process in young athletes. In youth soccer, maturity-related changes in anthropometric and physical fitness characteristics are diverse among individuals, particularly around PHV. During this time, players are also at an increased risk of sustaining an overuse or growth-related injury. As a result, the implementation of training interventions can be challenging. The purpose of this review was to (1) highlight and discuss many of the methods that can be used to estimate maturation in the applied setting and (2) discuss the implications of manipulating training load around PHV on physical development and injury risk. We have provided key stakeholders with a practical online tool for estimating player maturation status (Supplementary Maturity Estimation Tools). Whilst estimating maturity using predictive equations is useful in guiding the training process, practitioners should be aware of its limitations. To increase the accuracy and usefulness of data, it is also vital that sports scientists implement reliable testing protocols at predetermined time-points.


Asunto(s)
Desarrollo del Adolescente/fisiología , Traumatismos en Atletas/fisiopatología , Rendimiento Atlético/fisiología , Pesos y Medidas Corporales , Desarrollo Infantil/fisiología , Rendimiento Físico Funcional , Fútbol/fisiología , Adolescente , Niño , Humanos , Encuestas y Cuestionarios
11.
Physiol Behav ; 229: 113252, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33220329

RESUMEN

PURPOSE: The brain can utilise medium chain triglycerides (MCTs) as an alternative fuel to glucose, and research has shown that MCT ingestion improves cognitive function in diseased and/or elderly individuals. The aim of this study is to determine if these improvements can also be observed in young, healthy adults. Furthermore, we aim to establish the ideal dosage and timeframe necessary for an effect. METHODS: Participants were divided equally into three groups of 10 (Placebo (0 g), 12 g and 18 g MCT/day) and were supplemented for 4 weeks. The supplement had a C8:C10 ratio of 30:70. Participants visited the laboratory once a week for 5 weeks (baseline, test weeks 1-4) to undergo a battery of cognitive tests; Trail Making, Digit Span, Spatial Span, Covert Shift of Attention, and Rapid Visual Information Processing. RESULTS: After 2-3 weeks of supplementation, MCT ingestion enhanced performance in cognitive tasks, including: Trail Making A/B and Digit Span Forwards/Backwards (ps<0.001) when compared to a placebo group taking a carbohydrate gel. In Spatial Span Backwards, there was a significant main effect of group (p = 0.002). Where significance was seen, there were main effects of time after 2-3 weeks (ps<0.05). There was minimal difference between the two MCT intervention groups in most measures (ps>0.05). There were also null results in tasks measuring attention and reaction time (ps>0.05). CONCLUSIONS: MCT ingestion improved cognitive performance after 2-3 weeks, with minimal difference between taking 12 g and 18 g MCT/day groups, suggesting a possible dose-response threshold at 12 g MCT/day when supplementing over a short period.


Asunto(s)
Cognición , Suplementos Dietéticos , Anciano , Encéfalo , Humanos , Pruebas Neuropsicológicas , Triglicéridos , Adulto Joven
12.
Eur J Appl Physiol ; 120(4): 873-882, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32086599

RESUMEN

PURPOSE: The effect of hyperglycaemia on exercise with low and elevated muscle glycogen on glucose utilization (GUR), carbohydrate and fat oxidation, hormonal and metabolite responses, as well as rating of perceived exertion (RPE) were explored. METHODS: Five healthy trained males were exercised for 90 min at 70% V̇O2max in two trials, while glucose was infused intravenously at rates to "clamp" blood glucose at 12 mM. On one occasion, participants were 'loaded' with carbohydrate (CHO-L), whilst on a separate occasion, participants were glycogen depleted (CHO-D). Prior exercise and dietary manipulations produced the 'loaded' and 'depleted' states. RESULTS: The CHO-L and CHO-D conditions resulted in muscle glycogen concentrations of 377 and 159 mmol/g dw, respectively. Hyperglycaemia elevated plasma insulin concentrations with higher levels for CHO-L than for CHO-D (P < 0.01). Conversely, CHO-D elevated plasma adrenaline and noradrenaline higher than CHO-L (P < 0.05). Plasma fat metabolites (NEFA, ß-hydroxybutyrate, and glycerol) were higher under CHO-D than CHO-L (P < 0.01). The resultant was that the rates of total carbohydrate and fat oxidation were elevated and depressed for loaded CHO-L vs CHO-D respectively (P < 0.01), although no difference was found for GUR (P > 0.05). The RPE over the exercise period was higher for CHO-D than CHO-L (P < 0.05). CONCLUSION: Hyperglycaemia during exercise, when muscle glycogen is reduced, attenuates insulin but promotes catecholamines and fat metabolites. The effect is a subsequent elevation of fat oxidation, a reduction in CHO oxidation without a concomitant increase in GUR, and an increase in RPE.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Dieta de Carga de Carbohidratos , Ejercicio Físico/fisiología , Glucógeno/deficiencia , Hiperglucemia/fisiopatología , Metabolismo de los Lípidos , Adolescente , Adulto , Estudios Cruzados , Voluntarios Sanos , Hormonas/sangre , Humanos , Masculino , Músculo Esquelético/metabolismo , Oxidación-Reducción , Esfuerzo Físico , Adulto Joven
13.
Int J Sports Med ; 41(2): 89-97, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31801172

RESUMEN

The purpose of the present study was to examine the influence of workload prior to injury on injury (tissue type and severity) in professional soccer players. Twenty-eight days of retrospective training data prior to non-contact injuries (n=264) were collated from 192 professional soccer players. Each injury tissue type (muscle, tendon and ligament) and severity (days missed) were categorised by medical staff. Training data were recorded using global positioning system (GPS) devices for total distance (TD), high speed distance (HSD,>5.5 m/s-1), and sprint distance (SPR,>7.0 m/s-1). Accumulated 1, 2, 3, 4-weekly loads and acute:chronic workload ratios (ACWR) (coupled, uncoupled and exponentially weighted moving average (EWMA) approaches) were calculated. Workload variables and injury tissue type were compared using a one-way ANOVA. The association between workload variables and injury severity were examined using a bivariate correlation. There were no differences in accumulated weekly loads and ACWR calculations between muscle, ligament, and tendon injuries (P>0.05). Correlations between each workload variable and injury severity highlighted no significant associations (P>0.05). The present findings suggest that the ability of accumulated weekly workload or ACWR methods to differentiate between injury type and injury severity are limited using the present variables.


Asunto(s)
Ligamentos/lesiones , Músculo Esquelético/lesiones , Acondicionamiento Físico Humano/efectos adversos , Fútbol/lesiones , Traumatismos de los Tendones/epidemiología , Europa (Continente)/epidemiología , Sistemas de Información Geográfica , Humanos , Incidencia , Puntaje de Gravedad del Traumatismo , Extremidad Inferior/lesiones , Acondicionamiento Físico Humano/métodos , Estudios Retrospectivos , Carrera/lesiones , Dispositivos Electrónicos Vestibles
14.
Eur J Appl Physiol ; 120(1): 127-135, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31707476

RESUMEN

PURPOSE: The effect of hyperglycaemia with and without additional insulin was explored at a low and high intensity of exercise (40% vs 70% VO2peak) on glucose utilization (GUR), carbohydrate oxidation, non-oxidative glucose disposal (NOGD), and muscle glycogen. METHODS: Eight healthy trained males were exercised for 120 min in four trials, twice at 40% VO2peak and twice at 70% VO2peak, while glucose was infused intravenously (40%G; 70%G) at rates to "clamp" blood glucose at 10 mM. On one occasion at each exercise intensity, insulin was also infused at 40 mU/m2/per min (i.e. 40%GI and 70%GI). The glucose and insulin infusion began 30 min prior to exercise and throughout exercise. A muscle biopsy was taken at the end of exercise for glycogen analysis. RESULTS: Hyperglycaemia significantly elevated plasma insulin concentration (p < 0.001), although no difference was observed between the exercise intensities. Insulin infusion during both mild and severe exercise resulted in increased insulin concentrations (p < 0.01) and GUR (p < 0.01) compared with glucose (40%GI by 25.2%; 70%GI by 26.2%), but failed to significantly affect carbohydrate, fat and protein oxidation. NOGD was significantly higher for GI trials at both intensities (p < 0.05) with storage occurring during both lower intensities (62.7 ± 19.6 g 40%GI; 127 ± 20.7 g 40%GI) and 70%GI (29.0 ± 20.0 g). Muscle glycogen concentrations were significantly depleted from rest (p < 0.01) after all four trials. CONCLUSION: Hyperinsulinaemia in the presence of hyperglycaemia during both low- and high-intensity exercise promotes GUR and NOGD, but does not significantly affect substrate oxidation.


Asunto(s)
Glucemia/metabolismo , Metabolismo Energético , Glucógeno/metabolismo , Entrenamiento de Intervalos de Alta Intensidad , Insulina/sangre , Adolescente , Adulto , Humanos , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología
15.
Eur J Sport Sci ; 19(2): 147-155, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30009684

RESUMEN

The purpose of the study was to examine the perspectives of both academics and practitioners in relation to forming applied collaborative sport science research within team sports. Ninety-three participants who had previously engaged in collaborative research partnerships within team sports completed an online survey which focused on motivations and barriers for forming collaborations using blinded sliding scale (0-100) and rank order list. Research collaborations were mainly formed to improve the team performance (Academic: 73.6 ± 23.3; Practitioner: 84.3 ± 16.0; effect size (ES = 0.54), small). Academics ranked journal articles' importance significantly higher than practitioners did (Academic: Mrank = 53.9; Practitioner: 36.0; z = -3.18, p = .001, p < q). However, practitioners rated one-to-one communication as more preferential (Academic: Mrank = 41.3; Practitioner 56.1; z = -2.62, p = .009, p < q). Some potential barriers were found in terms of staff buy in (Academic: 70.0 ± 25.5; Practitioner: 56.8 ± 27.3; ES = 0.50, small) and funding (Academic: 68.0 ± 24.9; Practitioner: 67.5 ± 28.0; ES = 0.02, trivial). Both groups revealed low motivation for invasive mechanistic research (Academic: 36.3 ± 24.2; Practitioner: 36.4 ± 27.5; ES = 0.01, trivial), with practitioners have a preference towards 'fast' type research. There was a general agreement between academics and practitioners for forming research collaborations. Some potential barriers still exist (e.g. staff buy in and funding), with practitioners preferring 'fast' informal research dissemination compared to the 'slow' quality control approach of academics.


Asunto(s)
Conducta Cooperativa , Investigación/organización & administración , Deportes , Femenino , Humanos , Masculino , Investigadores , Encuestas y Cuestionarios
16.
Eur J Appl Physiol ; 119(1): 235-245, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30353450

RESUMEN

PURPOSE: The purpose of the present study was to investigate the age-related carbohydrate oxidation and glucose utilisation rate response during exercise at the same relative intensity under hyperglycaemia in aged and young males. METHODS: 16 endurance-trained aged (n = 8; 69.1 ± 5.2 year) and young (n = 8; 22.4 ± 2.9 year) males were studied during 40 min of cycling exercise (60% [Formula: see text]) under both hyperglycaemic and euglycaemic (control) conditions. Venous blood samples were collected at baseline, post-infusion, mid- and post-exercise. Carbohydrate and fat oxidation rates were determined at both 15 and 35 min during exercise, and glucose utilisation rates were calculated. RESULTS: The aged group displayed significantly lower rates of carbohydrate oxidation during exercise during maintained hyperglycemia (15 min = 2.3 ± 0.4 vs. 1.6 ± 0.5 g min-1; 35 min = 2.3 ± 0.5 vs. 1.5 ± 0.5 g min-1) and control (15 min = 2.2 ± 0.4 vs. 1.6 ± 0.7 g min-1; 35 min = 1.9 ± 0.7 vs. 1.3 ± 0.7 g min-1) conditions (P = 0.01). The rate of glucose utilisation during exercise was also significantly reduced (85.76 ± 23.95 vs. 56.67 ± 15.09 µM kg-1 min-1). There were no differences between age groups for anthropometric measures, fat oxidation, insulin, glucose, NEFA, glycerol and lactate (P > 0.05) although hyperglycemia resulted in elevated glucose and insulin, and attenuated fat metabolite levels. CONCLUSION: Our findings highlight that ageing results in a reduction in carbohydrate oxidation and utilisation rates during exercise at the same relative exercise intensity.


Asunto(s)
Envejecimiento/metabolismo , Glucemia/metabolismo , Metabolismo de los Hidratos de Carbono , Ejercicio Físico , Hiperglucemia/metabolismo , Adulto , Anciano , Envejecimiento/fisiología , Humanos , Masculino , Oxidación-Reducción , Consumo de Oxígeno
17.
Int J Sports Physiol Perform ; 13(5): 562-567, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28422524

RESUMEN

PURPOSE: To investigate the difference between straight-line (STL) and change-of-direction (COD) intermittent-running exercises in soccer players. METHODS: Seventeen male professional soccer players performed the agility T test and 6 intermittent-running exercises: 10 s at 130% of maximal aerobic speed (MAS) alternated with 10 s of rest (10-10), 15 s at 120% of MAS alternated with 15 s of rest (15-15), and 30 s at 110% of MAS alternated with 30 s of rest (30-30) both in STL and with COD. All exercises were monitored using a global positioning system. Heart rate was measured during exercises, and rating of perceived exertion (RPE) was collected postexercise. The difference (Δ) between covered distance in STL and COD exercises at a similar load was calculated, and relationships between T test and Δ distance were analyzed. RESULTS: COD intermittent exercises showed a significantly decreased distance covered and an increase in the number of accelerations, peak heart rate, and RPE compared with STL intermittent exercises at a similar load. High relationships were observed between T-test performance and Δ distance in 10-10 (r = .72, P < .01) and 15-15 (r = .77, P < .01), whereas no significant relationships were observed between T-test performance and Δ distance in 30-30 (r = -.37, P = .2). CONCLUSION: Intermittent COD exercises were associated with higher acceleration, peak heart rate, and RPE than STL during 10-10 and 15-15 exercises. The ability to rapidly change direction is crucial to perform intense sport-specific running in professional soccer players.


Asunto(s)
Destreza Motora/fisiología , Carrera/fisiología , Fútbol/fisiología , Aceleración , Adulto , Prueba de Esfuerzo , Sistemas de Información Geográfica , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Percepción/fisiología , Resistencia Física/fisiología , Esfuerzo Físico/fisiología
18.
Int J Sports Physiol Perform ; 13(5): 672-675, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29182417

RESUMEN

The purpose of this investigation was to (1) quantify the training load practices of a professional soccer goalkeeper and (2) investigate the relationship between the training load observed and the subsequent self-reported wellness response. One male goalkeeper playing for a team in the top league of the Netherlands participated in this case study. Training load data were collected across a full season using a global positioning system device and session-RPE (rating of perceived exertion). Data were assessed in relation to the number of days to a match (MD- and MD+). In addition, self-reported wellness response was assessed using a questionnaire. Duration, total distance, average speed, PlayerLoad™, and load (derived from session-RPE) were highest on MD. The lowest values for duration, total distance, and PlayerLoad™ were observed on MD-1 and MD+1. Total wellness scores were highest on MD and MD-3 and were lowest on MD+1 and MD-4. Small to moderate correlations between training load measures (duration, total distance covered, high deceleration efforts, and load) and the self-reported wellness response scores were found. This exploratory case study provides novel data about the physical load undertaken by a goalkeeper during 1 competitive season. The data suggest that there are small to moderate relationships between training load indicators and self-reported wellness response. This weak relation indicates that the association is not meaningful. This may be due to the lack of position-specific training load parameters that practitioners can currently measure in the applied context.


Asunto(s)
Estado de Salud , Acondicionamiento Físico Humano , Fútbol/fisiología , Conducta Competitiva/fisiología , Humanos , Masculino , Países Bajos , Percepción/fisiología , Esfuerzo Físico/fisiología , Carrera/fisiología , Estaciones del Año , Autoinforme , Encuestas y Cuestionarios , Adulto Joven
19.
Adv Physiol Educ ; 41(4): 569-571, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29138214

RESUMEN

Sport science has gained vast popularity with students who have an interest in both physiology and the underpinning mechanisms of exercise concerning performance and health. The high numbers of graduates each year, coupled with the low number of graduate positions working in sports, has led to a high level of competition between students. To stand out from the crowd, sport science students may undertake an internship placement as part of their course, designed to enhance theoretical, practical, and soft skills in an applied setting. In the present article, we highlight some of the positives and negatives of sport science internships and ways in which they can be implemented and facilitated. Suggestions have also been provided to make students more aware of the reality of working in professional sports, which includes awareness of the potential for long and unsociable hours of work.


Asunto(s)
Internado no Médico/métodos , Aprendizaje , Medicina Deportiva/métodos , Deportes/educación , Humanos , Internado no Médico/normas , Deportes/normas , Medicina Deportiva/normas , Estudiantes
20.
Int J Sports Physiol Perform ; 12(8): 1059-1068, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28051343

RESUMEN

PURPOSE: Sprints and accelerations are popular performance indicators in applied sport. The methods used to define these efforts using athlete-tracking technology could affect the number of efforts reported. This study aimed to determine the influence of different techniques and settings for detecting high-intensity efforts using global positioning system (GPS) data. METHODS: Velocity and acceleration data from a professional soccer match were recorded via 10-Hz GPS. Velocity data were filtered using either a median or an exponential filter. Acceleration data were derived from velocity data over a 0.2-s time interval (with and without an exponential filter applied) and a 0.3-second time interval. High-speed-running (≥4.17 m/s2), sprint (≥7.00 m/s2), and acceleration (≥2.78 m/s2) efforts were then identified using minimum-effort durations (0.1-0.9 s) to assess differences in the total number of efforts reported. RESULTS: Different velocity-filtering methods resulted in small to moderate differences (effect size [ES] 0.28-1.09) in the number of high-speed-running and sprint efforts detected when minimum duration was <0.5 s and small to very large differences (ES -5.69 to 0.26) in the number of accelerations when minimum duration was <0.7 s. There was an exponential decline in the number of all efforts as minimum duration increased, regardless of filtering method, with the largest declines in acceleration efforts. CONCLUSIONS: Filtering techniques and minimum durations substantially affect the number of high-speed-running, sprint, and acceleration efforts detected with GPS. Changes to how high-intensity efforts are defined affect reported data. Therefore, consistency in data processing is advised.


Asunto(s)
Rendimiento Atlético/fisiología , Sistemas de Información Geográfica , Carrera/fisiología , Fútbol/fisiología , Aceleración , Conducta Competitiva/fisiología , Humanos , Movimiento/fisiología , Programas Informáticos , Adulto Joven
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