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PURPOSE: To test the hypothesis that training with reduced carbohydrate (CHO) availability increases bone resorption in adolescent soccer players. METHODS: In a randomised crossover design, ten male players (age: 17.4 ± 0.8 years) from an English Premier League academy completed an acute 90-min field-based training session (occurring between 10:30-12:00) in conditions of high (TRAIN HIGH; 1.5 g.kg-1, 60 g, 1.5 g.kg-1 and 1.5 g.kg-1 consumed at 08:00, during training, 12:30 and 13:30, respectively) or low CHO availability (TRAIN LOW; 0 g.kg-1). Participants also completed a non-exercise trial (REST) under identical dietary conditions to TRAIN LOW. Venous blood samples were obtained at 08:30, 10:30, 12:30 and 14:30 for assessment of bone resorption (ßCTX), bone formation (PINP) and calcium metabolism (PTH and ACa). RESULTS: External training load did not differ (all P > 0.05) between TRAIN HIGH and TRAIN LOW, as evident for total distance (5.6 ± 0.8; 5.5 ± 0.1 km), average speed (81 ± 9; 85 ± 12 m.min-1) and high-speed running (350 ± 239; 270 ± 89 m). Area under the curve for both ßCTX and PINP was significantly greater (P < 0.01 and P = 0.03) in TRAIN LOW versus TRAIN HIGH, whilst no differences in PTH or ACa (P = 0.11 and P = 0.89) were observed between all three trials. CONCLUSION: CHO restriction before, during and after an acute soccer training session increased bone (re)modelling markers in academy players. Despite acute anabolic effects of bone formation, the long-term consequence of bone resorption may impair skeletal development and increase injury risk during growth and maturation.
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Female soccer players have been identified as presenting with low energy availability (LEA), though the prevalence of LEA may be overestimated given inaccuracies associated with self-reporting dietary intakes. Accordingly, we aimed to quantify total daily energy expenditure (TDEE) via the doubly labelled water (DLW) method, energy intake (EI) and energy availability (EA). Adolescent female soccer players (n = 45; 16 ± 1 years) completed a 9-10 day 'training camp' representing their national team. Absolute and relative TDEE was 2683 ± 324 and 60 ± 7 kcal kg-1 fat free mass (FFM), respectively. Mean daily EI was lower (P < 0.01) when players self-reported using the remote food photography method (RFPM) (2047 ± 383 kcal day-1) over a 3-day period versus DLW derived EI estimates accounting for body mass (BM) changes (2545 ± 518 kcal day-1) over 7-8 days, representing a mean daily Δ of 499 ± 526 kcal day-1 and 22% error when using the RFPM. Estimated EA was different (P < 0.01) between methods (DLW: 48 ± 14 kcal kg-1 FFM, range: 22-82; RFPM: 37 ± 8 kcal kg-1 FFM, range: 22-54), such that prevalence of LEA (<30 kcal kg-1 FFM) was lower in DLW compared with RFPM (5% vs. 15%, respectively). Data demonstrate the potential to significantly underestimate EI when using self-report methods. This approach can therefore cause a misrepresentation and an over-prevalence of LEA, which is the underlying aetiology of 'relative energy deficiency in sport' (REDs). HIGHLIGHTS: What is the central question of this study? Do self-reported dietary intakes (via remote food photography method, RFPM) overestimate low energy availability (LEA) prevalence in female soccer players compared with energy intake evaluation from the doubly labelled water (DLW) method? What is the main finding and its importance? Estimated energy availability is greater with the DLW method compared with RFPM, such that the prevalence of LEA is greater when self-reporting dietary intakes. Accordingly, data demonstrate the potential to misrepresent the prevalence of LEA, an underlying factor in the aetiology of 'relative energy deficiency in sport' (REDs).
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Endurance athletes fail to meet carbohydrate (CHO) guidelines for competition, which may be due to limited knowledge. However, the relationship between knowledge and practice in this population is unknown. To investigate this, we assessed the dietary intake in 50 athletes (37 females) who completed endurance events ≥2.5 h in duration and compared CHO intake against the carbohydrates for endurance athletes in competition questionnaire validated nutrition knowledge questionnaire, with specific questions related to CHO loading, pre-competition meal and during-competition intake. CHO-loading guidelines (10-12 g · kg-1 · day-1) were met in practice by n = 5 (10%), but there was no relationship between identified requirements (range 0-12 g · kg-1 · day-1) and actual intake (rs = 0.133, p = 0.358), with the n = 18 (36%) who correctly identified requirements, ingesting 6.1 ± 1.9 g · kg-1 · day-1. CHO intake for pre-competition meal guidelines (1-4 g · kg-1) was met in practice by n = 40 (80%), but there was no relationship between identified requirements (range 0 to >4 g · kg-1) and actual intake (rs = 0.101, p = 0.487), with n = 19 (38%) who correctly identified guidelines requirements, ingesting 1.4 ± 0.6 g · kg-1. CHO intake during-competition guidelines (60-90 g · h-1) was met in practice by n = 18 (36%), but there was no relationship between the amounts of CHO required (range 30 to >90 g/h) and actual intake (rs = 0.028, p = 0.849), with n = 32 (64%) who correctly identified guidelines requirements, ingesting 56 ± 20 g · h-1. Results show no relationship between the knowledge of CHO recommendations and practice, suggesting that theoretical knowledge does not guarantee the achievement of best practice and other important factors may ultimately determine practice.
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PURPOSE: Whey protein ingestion is typically considered an optimal dietary strategy to maximize myofibrillar protein synthesis (MyoPS) after resistance exercise. Although single-source plant protein ingestion is typically less effective, at least partly, due to less favorable amino acid profiles, this could theoretically be overcome by blending plant-based proteins with complementary amino acid profiles. We compared the postexercise MyoPS response after the ingestion of a novel plant-derived protein blend with an isonitrogenous bolus of whey protein. METHODS: Ten healthy, resistance-trained, young adults (male/female: 8/2; age: 26 ± 6 yr; BMI: 24 ± 3 kg·m -2 ) received a primed continuous infusion of L-[ ring - 2 H 5 ]-phenylalanine and completed a bout of bilateral leg resistance exercise before ingesting 32 g protein from whey (WHEY) or a plant protein blend (BLEND; 39.5% pea, 39.5% brown rice, 21.0% canola) in a randomized, double-blind crossover fashion. Blood and muscle samples were collected at rest, and 2 and 4 h after exercise and protein ingestion, to assess plasma amino acid concentrations, and postabsorptive and postexercise MyoPS rates. RESULTS: Plasma essential amino acid availability over the 4 h postprandial postexercise period was ~44% higher in WHEY compared with BLEND ( P = 0.04). From equivalent postabsorptive values (WHEY, 0.042 ± 0.020%·h -1 ; BLEND, 0.043 ± 0.015%·h -1 ) MyoPS rates increased after exercise and protein ingestion (time effect; P < 0.001) over a 0- to 2-h period (WHEY, 0.085 ± 0.037%·h -1 ; BLEND, 0.080 ± 0.037%·h -1 ) and 2- to 4-h period (WHEY, 0.085 ± 0.036%·h -1 ; BLEND, 0.086 ± 0.034%·h -1 ), with no differences between conditions during either period or throughout the entire (0-4 h) postprandial period (time-condition interactions; all P > 0.05). CONCLUSIONS: Ingestion of a novel plant-based protein blend stimulates postexercise MyoPS to an equivalent extent as whey protein, demonstrating the utility of plant protein blends to optimize postexercise skeletal muscle reconditioning.
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Estudios Cruzados , Proteínas Musculares , Miofibrillas , Entrenamiento de Fuerza , Proteína de Suero de Leche , Humanos , Adulto , Masculino , Proteína de Suero de Leche/administración & dosificación , Femenino , Método Doble Ciego , Adulto Joven , Proteínas Musculares/biosíntesis , Miofibrillas/metabolismo , Aminoácidos/sangre , Aminoácidos/administración & dosificación , Músculo Esquelético/metabolismo , Periodo Posprandial , Proteínas de Plantas/administración & dosificación , Fenilalanina/sangre , Fenilalanina/administración & dosificación , OryzaRESUMEN
This study aimed to explore player and stakeholder perceptions of the role of nutrition in influencing the development of male academy soccer players. Semi-structured interviews (28 ± 13 mins in length) were conducted with 31 participants from an English category one academy, including players (Youth Development Phase, YDP: n = 6; Professional Development Phase, PDP: n = 4), parents/guardians (n = 10), coaches (n = 3), sport scientists (n = 3), physiotherapists (n = 3), and catering (n = 2). Via reflexive thematic analysis, data demonstrate an apparent lack of understanding and awareness on the role of nutrition in influencing player development, especially in relation to growth, maturation and reducing injury risk. Players highlighted the influence of their parents on their dietary behaviours, whilst parents also called for education to better support their sons. Notably, players and stakeholders perceived that the daily schedule of an academy soccer player presents as "too busy to eat", especially in relation to before school, and before and after training. The results demonstrate the necessity for the co-creation of player and stakeholder specific nutrition education programmes as an initial step towards positively impacting the nutrition culture associated with the academy soccer environment.
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Fútbol , Deportes , Adolescente , Humanos , Masculino , Fútbol/lesiones , Dieta , Estado Nutricional , Instituciones AcadémicasRESUMEN
Understanding the daily energy expenditure of athletes during training is important to support recovery, adaptation, and the maintenance of performance. The aim of the current research was to assess the total daily energy expenditure (TDEE) and the acute energy expenditure (EE) of tennis training sessions during habitual training of elite tennis players. Using a cohort study design, 27 (n = 10, male; age; 22.3 ± 3.2 years and n = 17, female; age: 23.8 ± 3.5 years) elite singles tennis players were assessed for TDEE and tennis training EE. Using Actiheart activity monitors during a 2- to 5-day training period, male players were analyzed for 26 days and 33 (1.3 ± 0.5 sessions/day) tennis training sessions, and female players for 43 days and 58 (1.2 ± 0.4 sessions/day) tennis training sessions. Male TDEE (4,708 ± 583 kcal/day) was significantly higher than female (3,639 ± 305 kcal/day). Male absolute and relative tennis training EEs (10.2 ± 2.3 kcal/min and 7.9 ± 1.4 kcal·hr-1·kg-1) were significantly higher than those of females (7.6 ± 1.0 kcal/min and 6.8 ± 0.9 kcal·hr-1·kg-1). The resting metabolic rate was assessed via indirect calorimetry. The physical activity level for both groups was 2.3 AU. The TDEE of male and female players during habitual training now highlights the continual cycle of high energy demands experienced by the elite tennis player. The broad ranges of TDEE and EE reported here suggest individual assessment and nutritional planning be prioritized, with a particular focus on carbohydrate requirements.
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Tenis , Humanos , Masculino , Femenino , Adulto Joven , Adulto , Estudios de Cohortes , Metabolismo Energético , Metabolismo Basal , AtletasRESUMEN
PURPOSE: As a multidisciplined combat sport, relationships between external and internal training loads and intensities of mixed martial arts (MMA) have not been described. The aim of this study was to determine the external loads and intensities of MMA training categories and their relationship to internal loads and intensities. METHODS: Twenty MMA athletes (age = 23.3 [5.3] y, mass = 72.1 [7.2] kg, stature = 171.5 [8.4] cm) were observed for 2 consecutive weeks. Internal load and intensity (session rating of perceived exertion [sRPE]) were calculated using the Foster RPE for the session overall (sRPE-training load [TL]) and segmented RPE (segRPE-TL) for each training category: warm-up, striking drills, wrestling drills, Brazilian jiujitsu (BJJ) drills, striking sparring, wrestling sparring, BJJ sparring, and MMA sparring. External load and intensity were measured via Catapult OptimEye S5 for the full duration of each session using accumulated Playerload (PLdACC) and PLdACC per minute (PLdACC·min-1). Differences in loads between categories and days were assessed via Bayesian analysis of variance (BF10 ≥ 3). Predictive relationships between internal and external variables were calculated using Bayesian regression. RESULTS: Session overall sRPE-TL = 448.6 (191.1) arbitrary units (AU); PLdACC = 310.6 (112) AU. Category segRPE-TL range = 33.8 (22.6) AU (warm-up) to 122.8 (54.6) AU (BJJ drills). Category PLdACC range = 44 (36.3) AU (warm-up) to 125 (58.8) AU (MMA sparring). Neither sRPE-TL nor PLdACC changed between days. PLdACC was different between categories. Evidence for regressions was strong-decisive except for BJJ drills (BF10 = 7, moderate). R2 range = .50 to .77, except for warm-up (R2 = .17), BJJ drills (R2 = .27), BJJ sparring (R2 = .49), and session overall (R2 = .13). CONCLUSIONS: While MMA training categories may be differentiated in terms of external load, overall session external load does not change within or between weeks. Resultant regression equations may be used to appropriately plan MMA technical/tactical training loads.
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Artes Marciales , Acondicionamiento Físico Humano , Humanos , Adulto Joven , Adulto , Esfuerzo Físico , Teorema de Bayes , Frecuencia Cardíaca , AtletasRESUMEN
Previous studies demonstrate that "under-fuelling" (i.e., reduced carbohydrate (CHO) and energy intake (EI) in relation to recommended guidelines) is prevalent within adult female soccer players, the consequence of which may have acute performance and chronic health implications. However, the dietary practices of adolescent female soccer players, a population who may be particularly at risk for the negative aspects of low energy availability (LEA), are not well documented. Accordingly, we aimed to quantify EI and CHO intake, physical loading and estimated energy availability (EA) in elite national team adolescent female soccer players (n = twenty-three; age, 17.9 ± 0.5 years) during a 10-day training and game schedule comprising two match days on day six (MDa) and nine (MDb). The players self-reported their EI via the remote food photography method, whilst the physical loading and associated exercise energy expenditure were assessed via GPS technology. The relative CHO intake was significantly greater (all p < 0.05) on the day before the first match (MD-1a) (4.1 ± 0.8 g·kg-1), on the day before the second match (MD-1b) (4.3 ± 1.1 g·kg-1), MDa (4.8 ± 1.2 g·kg-1) and MDb (4.8 ± 1.4 g·kg-1) in comparison to most other days (<4 g·kg-1). The mean daily measured EA over the 10-day period was 34 ± 12 kcal·kg FFM-1·day-1 (with six players, i.e., 34%, presenting LEA), though, when adjusting the energy intake for potential under-reporting, these values changed substantially (44 ± 14 kcal·kg FFM-1·day-1, only one player was classed as presenting LEA). Such data suggest that the prevalence of LEA amongst female team sport athletes may be over-estimated. Nonetheless, players are still likely under-fuelling for the work required in relation to the daily CHO recommendations (i.e., >6 g·kg-1) for intensive training and game schedules. These data provide further evidence for the requirement to create and deliver targeted player and stakeholder education and behaviour change interventions (especially for younger athletes) that aim to promote increased daily CHO intake in female soccer players.
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Fútbol , Adulto , Humanos , Adolescente , Femenino , Carbohidratos de la Dieta , Ingestión de Energía , Examen Físico , Ejercicio Físico , Metabolismo EnergéticoRESUMEN
This study aimed to test the hypothesis that the total daily energy expenditure (TDEE) of male academy soccer players is greater than players not enrolled on a formalised academy programme. English Premier League academy (ACAD: n = 8, 13 years, 50 ± 6 kg, 88 ± 3% predicted adult stature, PAS) and non-academy players (NON-ACAD: n = 6, 13 years, 53 ± 12 kg, 89 ± 3% PAS) were assessed for TDEE (via doubly labelled water) during a 14-day in-season period. External loading was evaluated during training (ACAD: 8 sessions, NON-ACAD: 2 sessions) and games (2 games for both ACAD and NON-ACAD) via GPS, and daily physical activity was evaluated using triaxial accelerometry. Accumulative duration of soccer activity (ACAD: 975 ± 23 min, NON-ACAD: 397 ± 2 min; p < 0.01), distance covered (ACAD: 54.2 ± 8.3 km, NON-ACAD: 21.6 ± 4.7 km; p < 0.05) and time engaged in daily moderate-to-vigorous (ACAD: 124 ± 17 min, NON-ACAD: 79 ± 18 min; p < 0.01) activity was greater in academy players. Academy players displayed greater absolute (ACAD: 3380 ± 517 kcal · d-1, NON-ACAD: 2641 ± 308 kcal · d-1; p < 0.05) and relative TDEE (ACAD: 66 ± 6 kcal · kg · d-1, NON-ACAD: 52 ± 10 kcal · kg · d-1; p < 0.05) versus non-academy players. Given the injury risk associated with high training volumes during growth and maturation, data demonstrate the requirement for academy players to consume sufficient energy (and carbohydrate) intake to support the enhanced energy cost of academy programmes.
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Ingestión de Energía , Fútbol , Humanos , Adulto , Masculino , Agua , Carbohidratos de la Dieta , Ejercicio FísicoRESUMEN
Despite the well-documented role of carbohydrate (CHO) in promoting endurance exercise performance, endurance athletes typically fail to meet current recommendations in competition. Adequate nutrition knowledge is key to drive athletes' behaviour, but the current level of knowledge in this population is not known. The present study assessed knowledge of CHO for competition in an international cohort of endurance athletes using the Carbohydrates for Endurance Athletes in Competition Questionnaire (CEAC-Q). The CEAC-Q was completed by 1016 individuals (45 % female), from the United Kingdom (40 %), Australia/New Zealand (22 %), the United States of America/Canada (18 %) and other countries (21 %). Total CEAC-Q scores were 50 ± 20 % (mean ± sd), with no differences in scores between the five subsections (10 ± 5 points, P < 0â 001). Based on typical knowledge and frequency of correct answers, we defined questions with low (0-39 %), moderate (40-69 %) and high (70-100 %) knowledge at a population level. Knowledge deficiencies were identified in questions related to CHO metabolism (Low: 2 out of 5 questions (2/5), Moderate: 3/5), CHO-loading (Low: 2/5, Moderate: 1/5), pre-event CHO (Low: 2/5, Moderate: 2/5), CHO during exercise (Moderate: 4/5) and CHO for recovery (Low: 3/5, Moderate: 1/5). Current CHO amounts recommendations were identified correctly for CHO-loading, pre-competition meal, during competition >2â 5 h) and post-competition recovery by 28% (Low), 45 % (Moderate), 48 % (Moderate), and 29 % (Low), respectively. Our findings indicate that endurance athletes typically have limited knowledge of carbohydrate guidelines for competition, and we identify specific knowledge gaps that can guide targeted nutrition education to improve knowledge as an initial step towards optimal dietary practice.
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Atletas , Carbohidratos de la Dieta , Humanos , Femenino , Masculino , Ejercicio Físico , Dieta , Educación en SaludRESUMEN
PURPOSE: Carbohydrate (CHO) intake periodization via the sleep low train low (SL-TL) diet-exercise model increases fat oxidation during exercise and may enhance endurance-training adaptation and performance. Conversely, training under environmental heat stress increases CHO oxidation, but the potential of combined SL-TL and heat stress to enhance metabolic and performance outcomes is unknown. METHODS: Twenty-three endurance-trained males were randomly assigned to either control (n = 7, CON), SL-TL (n = 8, SLTemp ) or SL-TL + heat stress (n = 8, SLHeat ) groups and prescribed identical 2-week cycling training interventions. CON and SLTemp completed all sessions at 20°C, but SLHeat at 35°C. All groups consumed matched CHO intake (6 g·kg-1 ·day-1 ) but timed differently to promote low CHO availability overnight and during morning exercise in both SL groups. Submaximal substrate utilization was assessed (at 20°C), and 30-min performance tests (at 20 and 35°C) were performed Pre-, Post-, and 1-week post-intervention (Post+1). RESULTS: SLTemp improved fat oxidation rates at 60% MAP (~66% VO2peak ) at Post+1 compared with CON (p < 0.01). Compared with SLTemp , fat oxidation rates were significantly lower in SLHeat at Post (p = 0.02) and Post+1 (p < 0.05). Compared with CON, performance was improved at Post in SLTemp in temperate conditions. Performance was not different between any groups or time points in hot conditions. CONCLUSION: SL-TL enhanced metabolic adaptation and performance compared with CON and combined SL-TL and heat stress. Additional environmental heat stress may impair positive adaptations associated with SL-TL.
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Carbohidratos de la Dieta , Resistencia Física , Humanos , Masculino , Ejercicio Físico , Dieta , Adaptación Fisiológica , Respuesta al Choque TérmicoRESUMEN
We aimed to investigate the human skeletal muscle (SkM) DNA methylome after exercise in low-carbohydrate (CHO) energy-balance (with high-fat) conditions compared with exercise in low-CHO energy-deficit (with low-fat) conditions. The objective was to identify novel epigenetically regulated genes and pathways associated with "train-low sleep-low" paradigms. The sleep-low conditions included nine males that cycled to deplete muscle glycogen while reaching a set energy expenditure. Postexercise, low-CHO meals (protein matched) completely replaced (using high fat) or only partially replaced (low fat) the energy expended. The following morning, resting baseline biopsies were taken and the participants then undertook 75 minutes of cycling exercise, with skeletal muscle biopsies collected 30 minutes and 3.5 hours postexercise. Discovery of genome-wide DNA methylation was undertaken using Illumina EPIC arrays, and targeted gene expression analysis was conducted by quantitative RT-PCR. At baseline, participants under energy balance (high fat) demonstrated a predominantly hypermethylated (60%) profile across the genome compared to energy-deficit low-fat conditions. However, postexercise performed in energy balance (with high fat) elicited a more prominent hypomethylation signature 30 minutes postexercise in gene regulatory regions important for transcription (CpG islands within promoter regions) compared with exercise in energy-deficit (with low-fat) conditions. Such hypomethylation was enriched within pathways related to IL6-JAK-STAT signaling, metabolic processes, p53/cell cycle, and oxidative/fatty acid metabolism. Hypomethylation within the promoter regions of the genes; histone deacetylase 2 (HDAC2), MECR, IGF2, and c13orf16 were associated with significant increases in gene expression in the postexercise period in energy balance compared with an energy deficit. Furthermore, HDAC11 was oppositely regulated at the gene expression level compared with family member HDAC2, where HDAC11 was hypomethylated yet increased in energy-deficit compared with energy-balance conditions. Overall, we identify some novel epigenetically regulated genes associated with train-low sleep-low paradigms.NEW & NOTEWORTHY We identify novel epigenetically regulated genes associated with train-low sleep-low paradigms. Exercise under low-carbohydrate (CHO) energy-balance (high-fat) conditions elicited a more prominent DNA hypomethylation signature 30 minutes postexercise compared with low-CHO energy-deficit (low-fat) conditions. This was enriched within IL6-JAK-STAT signaling, metabolic processes, p53, cell cycle, oxidative phosphorylation, and fatty acid metabolism. Histone deacetylase (HDAC) family members 2, 4, 10, and 11 demonstrated hypomethylation, with HDAC2 and HDAC11 possessing alternative regulation of gene expression in energy balance versus deficit conditions.
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Epigenoma , Interleucina-6 , Masculino , Humanos , Interleucina-6/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Músculo Esquelético/metabolismo , Glucógeno/metabolismo , Ácidos Grasos/metabolismoRESUMEN
Jockeys are unique given that they make weight daily and, therefore, often resort to fasting and dehydration. Through increasing daily food frequency (during energy deficit), we have reported short-term improvements in jockey's body composition. While these changes were observed over 6-12 weeks with food provided, it is unclear whether such improvements can be maintained over an extended period during free-living conditions. We, therefore, assessed jockeys over 5 years using dual X-ray absorptiometry, resting metabolic rate, and hydration measurements. Following dietary and exercise advice, jockeys reduced fat mass from baseline of 7.1 ± 1.4 kg to 6.1 ± 0.7 kg and 6.1 ± 0.6 kg (p < .001) at Years 1 and 5, respectively. In addition, fat-free mass was maintained with resting metabolic rate increasing significantly from 1,500 ± 51 kcal/day at baseline to 1,612 ± 95 kcal/day and 1,620 ± 92 kcal/day (p < .001) at Years 1 and 5, respectively. Urine osmolality reduced from 816 ± 236 mOsmol/L at baseline to 564 ± 175 mOsmol/L and 524 ± 156 mOsmol/L (p < .001) at Years 1 and 5, respectively. The percent of jockeys consuming a regular breakfast significantly increased from 48% at baseline to 83% (p = .009) and 87% (p = .003) at Years 1 and 5, alongside regular lunch from 35% to 92% (p < .001) and 96% (p < .001) from baseline to Years 1 and 5, respectively. In conclusion, we report that improved body composition can be maintained in free-living jockeys over a 5-year period when appropriate guidance has been provided.
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Metabolismo Basal , Ingestión de Energía , Humanos , Masculino , Composición Corporal , Absorciometría de Fotón , DietaRESUMEN
PURPOSE: An understanding of an athlete's total daily energy expenditure (TEE) is necessary to inform nutritional strategies, particularly where daily training and competitive demands are highly variable. This observational case series assessed the TEE of elite tennis players during high-level competition. METHODS: Senior female singles participants (FS: n = 3; 21 [1] y; ranked Women's Tennis Association [WTA] top 125-375), an FS junior (n = 1; 16 y; ranked WTA top 350), and a men's doubles player (n = 1; 26 y; ranked Association of Tennis Professionals [ATP] top 5) were assessed for TEE (using the doubly labeled water method) during a 9- to 14-day period, which included training, Wimbledon Championships, WTA/ATP International Tournaments, Junior/Senior International Tennis Federation, and Wimbledon Junior Championships. One female (FS3) did not exercise from day 4 following injury. RESULTS: TEE for men's doubles was 4586 kcal·d-1 (67 kcal·kg-1 fat-free mass [FFM]; daily activity 98 [74] min). Noninjured adult female participants' TEEs were 3396 and 3948 kcal·d-1 (66 and 81 kcal·kg-1 FFM; daily activity durations were 139 [84] min and 150 [66] min, respectively), while TEE for the injured athlete was 2583 kcal·d-1 (45.7 kcal·kg-1; daily nonexercise activity duration was <45 min). The junior player TEE was 3988 kcal·d-1 (78.2 kcal·kg-1 FFM; daily activity of 131 [66] min). CONCLUSION: This observational case series positions tennis as a highly energetically demanding sport with variability evident between individuals (ie, TEE between 60 and 90 kcal·kg-1 FFM). Accordingly, nutritional strategies that promote sufficient energy availability should be emphasized with individual variability suitably assessed prior to prescription.
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Deportes , Tenis , Masculino , Adulto , Humanos , Femenino , Agua , Metabolismo Energético , Adenosina TrifosfatoRESUMEN
NEW FINDINGS: What is the central question of this study? Whole-body substrate utilisation is altered during exercise in hot environments, characterised by increased glycolytic metabolism: does heat stress alter the serum metabolome in response to high intensity exercise? What are the main finding and its importance? Alongside increases in glycolytic metabolite abundance, circulating amino acid concentrations are reduced following exercise under heat stress. Prior research has overlooked the impact of heat stress on protein metabolism during exercise, raising important practical implications for protein intake recommendations in the heat. ABSTRACT: Using untargeted metabolomics, we aimed to characterise the systemic impact of environmental heat stress during exercise. Twenty-three trained male triathletes ( V Ì O 2 peak ${\dot V_{{{\rm{O}}_2}{\rm{peak}}}}$ = 64.8 ± 9.2 ml kg min-1 ) completed a 30-min exercise test in hot (35°C) and temperate (21°C) conditions. Venous blood samples were collected immediately pre- and post-exercise, and the serum fraction was assessed via untargeted 1 H-NMR metabolomics. Data were analysed via uni- and multivariate analyses to identify differences between conditions. Mean power output was higher in temperate (231 ± 36 W) versus hot (223 ± 31 W) conditions (P < 0.001). Mean heart rate (temperate, 162 ± 10 beats min-1 , hot, 167 ± 9 beats min-1 , P < 0.001), peak core temperature (Trec ), core temperature change (ΔTrec ) (P < 0.001) and peak rating of perceived exertion (P = 0.005) were higher in hot versus temperate conditions. Change in metabolite abundance following exercise revealed distinct clustering following multivariate analysis. Six metabolites increased (2-hydroxyvaleric acid, acetate, alanine, glucarate, glucose, lactate) in hot relative to temperate (P < 0.05) conditions. Leucine and lysine decreased in both conditions but to a greater extent in temperate conditions (P < 0.05). Citrate (P = 0.04) was greater in temperate conditions whilst creatinine decreased in hot conditions only (P > 0.05). Environmental heat stress increased glycolytic metabolite abundance and led to distinct alterations in the circulating amino acid availability, including increased alanine, glutamine, leucine and isoleucine. The data highlight the need for additional exercise nutrition and metabolism research, specifically focusing on protein requirements for exercise under heat stress.
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Aminoácidos , Respuesta al Choque Térmico , Masculino , Humanos , Leucina , Ejercicio Físico/fisiología , Alanina , CalorRESUMEN
PURPOSE: This study aimed to test the hypothesis that a novel nutritional blend composed of tryptophan, glycine, magnesium, tart cherry powder, and l -theanine enhances subjective and objective measures of sleep during free living conditions. METHODS: In a randomized, repeated-measures crossover and double-blind deception design, participants ( n = 9 males and 7 females, age = 24 ± 3 yr, body mass = 69.8 ± 11.6 kg, stature = 170.8 ± 9.1 cm) completed a 3-d familiarization period, followed by 3-d intervention and placebo trials. Subjective Pittsburgh Quality Sleep Index, Core Consensus Sleep Diary, and Karolinska Sleepiness Scale survey tools, alongside objective actigraphy measures of sleep, were assessed, with daily nutritional intake, activity, and light exposure standardized between trials. Participants provided daily urine samples for assessment of targeted and untargeted metabolomes. RESULTS: The intervention trial reduced sleep onset latency (-24 ± 25 min; P = 0.002), increased total sleep time (22 ± 32 min; P = 0.01), and increased sleep efficiency (2.4% ± 3.9%; P = 0.03), while also reducing morning sleepiness ( P = 0.02). Throughout the study, 75% of participants remained blinded to sleep assessment as a primary outcome measure, with 56% subjectively indicating improved sleep during the intervention trial. Metabolomic analysis highlighted several significantly altered metabolomes related to sleep regulation between trials, inclusive of 6-sulfatoxymelatonin, d -serine, and l -glutamic acid. CONCLUSIONS: Data demonstrate that using the proposed blend of novel nutritional ingredients during free living conditions reduced sleep onset latency, increased total sleep duration, and increased sleep efficiency, leading to reduced perceptions of morning sleepiness. These effects may be mediated by the upregulation of key metabolites involved in the neurophysiological modulation of the sleep/wake cycle.
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Latencia del Sueño , Somnolencia , Masculino , Femenino , Humanos , Adulto Joven , Adulto , Sueño/fisiología , Actigrafía , Método Doble Ciego , DecepciónRESUMEN
To audit the current provision of performance nutrition services provided to male adolescent players within academies from the English soccer leagues. Practitioners from all 89 academies (status categorised as one-four according to the Elite Player Performance Plan, EPPP) completed an online survey to audit: a) job role/professional accreditation status of persons delivering nutrition support, b) activities inherent to service provision, c) topics of education, d) on-site food, fluid and supplement provision and e) nutritional related data collected for objective monitoring. More full-time accredited nutritionists are employed within category one (14/26) versus category two (0/18), three (1/41) and four (0/4). Respondents from category one clubs report more hours of monthly service delivery (62 ± 57 h) than category two (12 ± 9 h), three (14 ± 26 h) and four (12 ± 14 h), inclusive of one-to-one player support and stakeholder education programmes. Category one practitioners reported a greater prevalence of on-site food, fluid and supplement provision on training and match days. Across all categories, players from the professional development phase receive more frequent support than players from the youth development phase, despite the latter corresponding to the most rapid phase of growth and maturation. We report distinct differences in the extent of service provision provided between categories. Additionally, players from all categories receive nutrition support from non-specialist staff. Data demonstrate that performance nutrition appears an under-resourced component of academy sport science and medicine programmes in England, despite being an integral component of player development.
Asunto(s)
Fútbol , Adolescente , Humanos , Masculino , Inglaterra/epidemiología , Estado Nutricional , EscolaridadRESUMEN
PURPOSE: This qualitative study explores player and stakeholder perceptions of menstrual health support in elite female soccer. METHODS: Semi-structured interviews were conducted with 47 participants including players (n = 12), parents (n = 9), coaches (n = 9), sport scientists (n = 7), nutritionists (n = 5) and medical staff (n = 5). RESULTS: Via thematic analysis, data demonstrate that elite female soccer players experience a range of physical and psychological symptoms primarily at the onset of and during menses (as also perceived by stakeholders), with most participants perceiving these symptoms to impact performance. Nonetheless, menstrual health support is perceived as minimal and although players have their menstrual status tracked, they report little understanding as to why or how this information is used. This confusion was also present among stakeholders, often as a result of uncertainty about the evidence supporting the need for menstrual health support. The perceived lack of support may also be reflective of a culture where conversations about the menstrual cycle are not normalised. Overall, this may result in failure to identify and treat menstrual irregularities despite non-coaching staff members perceiving them to be common amongst players. CONCLUSION: These data support the need for individualised support based on the lived experiences of individual players and support staff. Furthermore, our research identifies the need for organisational, stakeholder, and player centred education programmes (led by experts in female athlete health) that create an environment where players receive personalised menstrual health support.
Asunto(s)
Fútbol , Humanos , Femenino , Fútbol/psicología , Menstruación , Ciclo Menstrual , Investigación Cualitativa , Atletas/psicologíaRESUMEN
Academy soccer players frequently train in the evening (i.e. 1700-2000 h), hence limited time to nutritionally prepare and recover due to schooling, travel and sleep schedules. Accordingly, we assessed timing and quantity of energy intake in the pre-training and post-training period. Over a 3-day in-season training period, male players (n=48; n=8 from under (U) 12, 13, 14, 15/16, 18 and 23 players) from an English Premier League academy self-reported dietary intake and physical activity levels (via the remote food photography method and activity diary, respectively) in the four hours pre- and post-training. Timing of pre-training energy intake ranged from 40 ± 28 mins (U15/U16 players) to 114 ± 71 mins (U18) before training and mean carbohydrate (CHO) intake ranged from 0.8±0.4 g.kg-1 (U23) to 1.5±0.9 g.kg-1 (U12). Timing of post-training energy intake ranged from 39 ± 27 mins (U14) to 70 ± 84 mins (U23) and mean CHO intake ranged from 1.6±0.8 g.kg-1 (U12) to 0.9±0.5 g.kg-1 (U14). In contrast to CHO, all age groups consumed sufficient protein intake in the post-training period (i.e. > 0.3 g.kg-1). We conclude academy soccer players habitually practice sub-optimal fuelling and recovery strategies, the consequence of which could impair growth, maturation and physical performance.
RESUMEN
Aim: This study aimed to explore athletes' experiences and opinions of communication strategies in applied sports nutrition, as well as capture suggestions for future mobile app supportive solutions. Methods: A qualitative approach was used for this research. Data was generated from semi-structured focus groups (n = 9) with a purposive sample of 41 (male = 24, female = 17) full time professional athletes (mean age 24 ± 4.59) from five sports (football, rugby union, athletics, cycling, and boxing). Data was analyzed using reflexive thematic analysis. Results: The analysis identified four higher order themes and five sub themes. Athletes appear dissatisfied with the levels of personalization in the nutrition support they receive. Limited practitioner contact time was suggested as a contributing factor to this problem. Athletes acknowledged the usefulness of online remote nutrition support and reported a desire for more personalized technology that can tailor support to their individual needs. Conclusion: Athletes experienced a hybrid human-computer approach that combines in-person and remote digital methods to communicate with and receive information from practitioners. Mobile technology may now afford sports nutritionists with new opportunities to develop scalable solutions to support practice.