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A Framework for Periodized Nutrition for Athletics
Abstract
Over the last decade, in support of training periodization, there has been an emergence around the concept of nutritional periodization. Within athletics (track and field), the science and art of periodization is a cornerstone concept with recent commentaries emphasizing the underappreciated complexity associated with predictable performance on demand. Nevertheless, with varying levels of evidence, sport and event specific sequencing of various training units and sessions (long [macrocycle; months], medium [mesocycle; weeks], and short [microcycle; days and within-day duration]) is a routine approach to training periodization. Indeed, implementation of strategic temporal nutrition interventions (macro, meso, and micro) can support and enhance training prescription and adaptation, as well as acute event specific performance. However, a general framework on how, why, and when nutritional periodization could be implemented has not yet been established. It is beyond the scope of this review to highlight every potential nutritional periodization application. Instead, this review will focus on a generalized framework, with specific examples of macro-, meso-, and microperiodization for the macronutrients of carbohydrates, and, by extension, fat. More specifically, the authors establish the evidence and rationale for situations of acute high carbohydrate availability, as well as the evidence for more chronic manipulation of carbohydrates coupled with training. The topic of periodized nutrition has made considerable gains over the last decade but is ripe for further scientific progress and field application.
... This has led to the creation of an amalgamation of targeted carbohydrate availability approaches (e.g. low, moderate, and high) throughout a microcycle [10,15, 26], whereby glycogen is 'cycled' to optimise physical performance and adaptations [30]. ...
... Nutrition practitioners often work in isolation. However, to achieve an optimal periodised nutrition approach, nutrition practitioners should deliver nutrition support as part of an integrated multidisciplinary team, with all key stakeholders (coach, athlete, nutritionist, conditioning coach, medical) all aligned on the physiological, neuromuscular, structural and psychological demands of the athletes' event, while understanding how the athlete can bridge any gaps to ensure success during competition [10]. Consequently, nutrition practitioners should periodise nutrition strategies on a microcycle level, ensuring that each one of the 4000 meals consumed by an athlete throughout an Olympic or Paralympic cycle is strategically placed and aligned to the coach's training periodisation and athletes' performance goal(s). ...
... Consequently, nutrition practitioners should periodise nutrition strategies on a microcycle level, ensuring that each one of the 4000 meals consumed by an athlete throughout an Olympic or Paralympic cycle is strategically placed and aligned to the coach's training periodisation and athletes' performance goal(s). [10] proposed that there needs to be better quanti cation of knowledge and application of nutritional periodisation approaches among athletes. ...
The concept of periodised nutrition is a well-established within performance nutrition support to appropriately fuel elite athletes while maximising the adaptative response from training. Despite this, there still appears to be little planning and integration of training prescription and nutrition between the nutritionist and multi-disciplinary team. Consequently, the aim of this current opinion was to (1) propose a ‘Periodised Nutrition System’ which can be utilised by nutrition practitioners when working with athletes; (2) discuss how this can be administered in practice, collaborating with the coach, multidisciplinary team and athlete; (3) present a case study of the proposed ‘nutrition periodisation system’ and its utilisation with a world class swimmer leading into the 2024 Olympic Games. The ‘Periodised Nutrition System’ presents different ‘performance plates’, quantities of different foods to fit into the ‘performance plates’ to aid recipe development, and how they may practically fit into an athlete’s periodisation alongside theoretical rationale. The case study demonstrates a ‘real world’ scenario of its utilisation with an elite swimmer, transitioning through three separate performance goals while reducing body mass by 1.9 kg, sum of eight skinfolds by 20.1mm, predicted fat mass by 2.6 kg and an increase in predicted lean mass by 0.6 kg over a six-week mesocycle. The study highlights that the ‘Periodised Nutrition System’ enables the practitioner to develop structure to their support aligning nutritional strategies with the training periodisation of the athlete, allowing for an individual approach, specific to the athlete’s performance goal(s) and the desired adaptation of a training session.
... Recently, our group described the consequences of low energy availability in athletes from a life history perspective (Shirley et al., 2022), and in relation to the energetic trade-offs that may occur when insufficient energy is available to simultaneously sustain all biological processes, along with the demands of training (Oliveira-Junior et al., 2021;Pontzer and McGrosky, 2022;Stearns, 1989). Briefly, energy is a finite resource, which must be distributed throughout the body to fuel all biological processes. ...
... Energy that is used for one function cannot be used for others, and so "trade-offs" between biological processes or tissues may occur. Competition between internal biological processes will be heightened when energy availability is low, and those considered most immediately essential to survival will be protected, even if this requires the diversion of energy away from, and potential downregulation of, others (Hill, 1993;Pontzer, 2018;Stearns, 1989). Compensation in the face of high activity expenditure unmet by adequate energy intake represents a form of energetic trade-off, the aim of which is to restore energy balance. ...
... The order in which different biological processes may be protected or downregulated during times of acute or chronic LEA has been described as the "hierarchy of functional preservation" and processes deemed more immediately essential to survival, are predicted to be protected, even if this comes at the expense of others (Ellison, 2003;Longman et al., 2023;Longman et al., 2020;Stearns, 1989). This hierarchy is likely to be impacted by a wide range of parameters, including the extent and duration of low energy availability along with individual (e.g., sex, age, body composition, training, nutrition and health status) and environmental (e.g., temperature and altitude) factors. ...
The Constrained Model of Total Energy Expenditure predicts that increased physical activity may not influence total energy expenditure, but instead, induces compensatory energetic savings in other processes. Much remains unknown, however, about concepts of energy expenditure, constraint and compensation in different populations, and it is unclear whether this model applies to endurance athletes, who expend very large amounts of energy during training and competition. Furthermore, it is well-established that some endurance athletes consciously or unconsciously fail to meet their energy requirements via adequate food intake, thus exacerbating the extent of energetic stress that they experience. Within this review we A) Describe unique characteristics of endurance athletes that render them a useful model to investigate energy constraints and compensations, B) Consider the factors that may combine to constrain activity and total energy expenditure, and C) Describe compensations that occur when activity energy expenditure is high and unmet by adequate energy intake. Our main conclusions are as follows: A) Higher activity levels, as observed in endurance athletes, may indeed increase total energy expenditure, albeit to a lesser degree than may be predicted by an additive model, given that some compensation is likely to occur; B) That while a range of factors may combine to constrain sustained high activity levels, the ability to ingest, digest, absorb and deliver sufficient calories from food to the working muscle is likely the primary determinant in most situations and C) That energetic compensation that occurs in the face of high activity expenditure may be primarily driven by low energy availability i.e., the amount of energy available for all biological processes after the demands of exercise have been met, and not by activity expenditure per se.
... Due to the variable training load and goals across training periods, nutritional needs may change. Therefore, to promote and support training goals, nutrition should also be periodized (6,7). Periodized nutrition means that macronutrient intake is modified between training periods to support the specific training goals while maintaining adequate micronutrient intake and energy availability (EA) and avoiding negative health and performance consequences (6,8,9). ...
... Therefore, to promote and support training goals, nutrition should also be periodized (6,7). Periodized nutrition means that macronutrient intake is modified between training periods to support the specific training goals while maintaining adequate micronutrient intake and energy availability (EA) and avoiding negative health and performance consequences (6,8,9). In particular, carbohydrate (CHO) requirements may vary significantly depending on the intensity, volume and goals of the training (6). ...
... Periodized nutrition means that macronutrient intake is modified between training periods to support the specific training goals while maintaining adequate micronutrient intake and energy availability (EA) and avoiding negative health and performance consequences (6,8,9). In particular, carbohydrate (CHO) requirements may vary significantly depending on the intensity, volume and goals of the training (6). In XC skiing, most competitions and key training sessions are performed at intensities that are highly dependent on CHO based fuels (3,10). ...
Purpose
(1) To evaluate if energy availability (EA), macronutrient intake and body composition change over four training periods in young, highly trained, female cross-country skiers, and (2) to clarify if EA, macronutrient intake, body composition, and competition performance are associated with each other in this cohort.
Methods
During a one-year observational study, 25 female skiers completed 3-day food and training logs during four training periods: preparation, specific preparation, competition, and transition periods. A body composition measurement (bioimpedance analyzer) was performed at the end of the preparation, specific preparation, and competition periods. Competition performance was determined by International Ski Federation (FIS) points gathered from youth national championships.
Results
EA (36–40 kcal·kg FFM ⁻¹ ·d ⁻¹ ) and carbohydrate (CHO) intake (4.4–5.1 g·kg ⁻¹ ·d ⁻¹ ) remained similar, and at a suboptimal level, between training periods despite a decrease in exercise energy expenditure ( p = 0.002) in the transition period. Higher EA ( r = −0.47, p = 0.035) and CHO intake ( r = −0.65, p = 0.002) as well as lower FM ( r = 0.60, p = 0.006) and F% ( r = 0.57, p = 0.011) were associated with lower (better) FIS-points. CHO intake was the best predictor of distance competition performance ( R ² = 0.46, p = 0.004).
Conclusions
Young female cross-country skiers had similar EA and CHO intake over four training periods. Both EA and CHO intake were at suboptimal levels for performance and recovery. CHO intake and body composition are important factors influencing competition performance in young female cross-country skiers.
... El Área de Nutrición Deportiva UCAD propone abordar la alimentación en atletas acorde a los volúmenes e intensidades que realizan, estableciendo los objetivos a través de un manejo que integra la alimentación al entrenamiento. Este enfoque, denominado periodización nutricional 19,20 , es el uso planificado, intencionado y estratégico de intervenciones nutricionales específicas para mejorar las adaptaciones a las que se dirigen las sesiones de ejercicio individuales o los planes de entrenamiento, o para obtener otros efectos que mejoren el rendimiento a largo plazo. Por lo tanto, la intervención nutricional deportiva contempla proporcionar pautas especificas de alimentación con el tipo, cantidad y el momento de la ingesta de alimentos y líquidos, promoviendo la salud y un rendimiento óptimo en diferentes escenarios de entrenamiento y competición 20,21 . ...
... Esto facilita organizar los recursos y esfuerzos, permitiendo al cuerpo técnico, equipo de ciencias y al propio atleta decidir qué es lo que se implementará, qué elementos se descartan, por cuánto tiempo se debe insistir con la modificación, entre otros. Por ejemplo, incrementar la masa muscular requiere semanas o meses, espacio de tiempo en el cual se debe cautelar que la cantidad de energía y proteínas estén en un balance positivo (adaptación crónica) 19 . ...
... Los elementos de la intervención nutricional se entrenan: todos los elementos nutricionales que se incorporan deben ser monitoreados y modelados en entrenamiento de forma previa a ser utilizados en competencia o a ser implementados permanentemente en el entrenamiento. Esto permite preparar al sistema digestivo para enfrentar los diferentes momentos de la ingesta (timing), volúmenes y formatos (e.g., la tolerancia a diferentes osmolaridades 19,20 . ...
Hoy en día es incuestionable la influencia de la alimentación en el deporte, de tal forma que la nutrición deportiva se reconoce como parte fundamental del bienestar, rendimiento y de las adaptaciones propias de la carga de entrenamiento planificada.
... Recent research suggests that nutrition goes beyond physical maintenance and is now recognized as a direct factor influencing performance [4]. Various physical functions, such as strength development, muscle recovery, fatigue recovery, and metabolic efficiency, are determined by nutritional status, and in high-stakes competitions, such as the Olympics, nutritional strategies can be key variables in determining success or failure [5,6]. The short bursts of power required for weightlifting predominantly rely on the adenosine triphosphate-phosphocreatine (ATP-PC) energy system, which provides rapid energy replenishment for maximum effort. ...
... They consider intricate details, such as nutrient interactions, timing of intake, and changes in nutritional requirements before and after exercise. This comprehensive approach allows for the development of sophisticated nutritional strategies that maximize performance and promote the rapid recovery of weightlifters, offering a data-driven nutritional management strategy [5]. This is evidence that modern sports nutrition is becoming increasingly precise, and such an approach is essential in high-intensity sports, such as weightlifting [31]. ...
Weightlifting demands explosive power and neuromuscular coordination in brief, repeated intervals. These physiological demands underscore the critical role of nutrition, not only in optimizing performance during competitions but also in supporting athletes’ rigorous training adaptations and ensuring effective recovery between sessions. As weightlifters strive to enhance their performance, well-structured nutritional strategies are indispensable. In this comprehensive review, we explored how weightlifters can optimize their performance through targeted nutritional strategies, including carbohydrate intake for glycogen replenishment and proteins for muscle growth and recovery. Additionally, the roles of key supplements, such as creatine, beta-alanine, and branch-chained amino acids in enhancing strength, delaying fatigue, and supporting muscle repair were discussed. A comprehensive literature review was conducted using PubMed, Google Scholar, and Web of Science to gather studies on nutritional strategies for weightlifting performance and training adaptation. The review focused on English-language articles relevant to weightlifters, including studies on powerlifting, while excluding those involving non-human subjects. Weightlifting requires explosive power, and proper nutrition is vital for performance and recovery, emphasizing the role of carbohydrate, protein, and fat intake. Nutrient timing and personalized strategies, informed by genetic and metabolomic analyses, enhance recovery and performance, while supplements like creatine, caffeine, and beta-alanine can significantly improve results when used correctly. Sustainable nutritional strategies are essential for enhancing weightlifter performance, emphasizing a balanced approach over extreme diets or excessive supplements. Further research is needed to refine these strategies based on individual athlete characteristics, ensuring consistent top-level performance throughout competitive seasons.
... The vast diversity of athletic events, each with its unique bioenergetic, biomechanical, and structural demands, requires a wide range of periodized nutrition combinations. Thus, nutritional training strategies for proteins, supplements, or carbohydrates should be implemented and their complications observed [95]. For example, in protein intake, considering the total amount, type, timing, and pattern of intake is crucial. ...
... Furthermore, interventions focused on nutrient timing have gained prominence, recognizing the critical importance of when nutrients are consumed [208]. Nutrient periodization, aligned with the diverse demands of different training phases and competition schedules, empowers athletes to strategically adjust their nutrient intake for optimized performance outcomes [95]. The triad of pre-, intra-, and post-exercise nutrition assumes pivotal significance in nutrient timing strategies, tailoring nutrition to fuel physical exertion, maintain energy levels, and initiate the recovery process [209]. ...
Citation: Martín-Rodríguez, A.; Belinchón-deMiguel, P.; Rubio-Zarapuz, A.; Tornero-Aguilera, J.F.; Martínez-Guardado, I.; Villanueva-Tobaldo, C.V.; Clemente-Suárez, V.J. Advances in Understanding the Interplay between Dietary Practices, Body Composition, and Sports Performance in Athletes. Nutrients 2024, 16, 571. Abstract: The dietary practices of athletes play a crucial role in shaping their body composition, influencing sports performance, training adaptations, and overall health. However, despite the widely acknowledged significance of dietary intake in athletic success, there exists a gap in our understanding of the intricate relationships between nutrition, body composition, and performance. Furthermore, emerging evidence suggests that many athletes fail to adopt optimal nutritional practices, which can impede their potential achievements. In response, this Special Issue seeks to gather research papers that delve into athletes' dietary practices and their potential impacts on body composition and sports performance. Additionally, studies focusing on interventions aimed at optimizing dietary habits are encouraged. This paper outlines the key aspects and points that will be developed in the ensuing articles of this Special Issue.
... Another factor that determines the sprint is the Biometric factor because, in a sprint, running speed is primarily determined by the frequency of the stride and the length of the stride. Running short distances is very good for building cardiovascular capacity, physical strength, and endurance (43). Running short distances can also help reduce visceral fat. ...
... In the jump and throw number groups, these numbers relate to the biomechanical aspect, which has the same thing, namely the existence of parabolic motion, which determines high achievement (36). In the number of throws, objects thrown by the thrower, such as bullets, discs, javelins, and hammerheads, will experience parabolic movements (43). The test form used is to throw the ball back over the top of the head. ...
... Nutritional intake is an essential component influencing exercise adherence and aerobic/ anaerobic sports performance [1][2][3][4][5][6][7]. As part of this, metabolic responses to dietary intake can provide strategic advantages when planning and undertaking exercise programs [8]. ...
... However, no post-hoc differences were observed between NORM and LOW (P > 0.05). There was also a main diet effect found for L%CO 2 Data presented as mean ± SE. sTIME = mean exercise session duration; sHR = mean session heart rate; sRPE = mean session perceived exertion rating using a 0-10 visual analogue scale; TL = mean weekly intervention training load (AU; arbitrary units); TM = mean weekly training monotony based on TL; TS = mean weekly estimated training strain. For the final measure for each day (pre-bed), a significant main effect was found for both L%CO 2 (F = 6.18, ...
Background
Based on stoichiometric assumptions, and real-time assessment of expired carbon dioxide (%CO2) and flow rate, the Lumen device provides potential for consumers/athletes to monitor metabolic responses to dietary programs outside of laboratory conditions. However, there is a paucity of research exploring device efficacy. This study aimed to evaluate Lumen device response to: i) a high-carbohydrate meal under laboratory conditions, and ii) a short-term low- or high-carbohydrate diet in healthy volunteers.
Methods
Following institutional ethical approval, 12 healthy volunteers (age: 36 ± 4 yrs; body mass: 72.1 ± 3.6 kg; height: 1.71 ± 0.02 m) performed Lumen breath and Douglas bag expired air measures under fasted laboratory conditions and at 30 and 60 min after a high-carbohydrate (2 g·kg⁻¹) meal, along with capilliarized blood glucose assessment. Data were analyzed using a one-way ANOVA, with ordinary least squares regression used to assess the model between Lumen expired carbon dioxide percentage (L%CO2) and respiratory exchange ratio (RER). In a separate phase, 27 recreationally active adults (age: 42 ± 2 yrs; body mass: 71.9 ± 1.9 kg; height: 1.72 ± 0.02 m) completed a 7-day low- (~20% of energy intake [EI]; LOW) or high-carbohydrate diet (~60% of EI; HIGH) in a randomized, cross-over design under free-living conditions. L%CO2 and derived Lumen Index (LI) were recorded daily across morning (fasted and post-breakfast) and evening (pre/post meal, pre-bed) periods. Repeated measures ANOVA were employed for main analyses, with Bonferroni post-hoc assessment applied (P ≤ 0.05).
Results
Following the carbohydrate test-meal, L%CO2 increased from 4.49 ± 0.05% to 4.80 ± 0.06% by 30 min, remaining elevated at 4.76 ± 0.06% by 60 min post-feeding (P < 0.001, ηp² = 0.74). Similarly, RER increased by 18.1% from 0.77 ± 0.03 to 0.91 ± 0.02 by 30 min post-meal (P = 0.002). When considering peak data, regression analysis demonstrated a significant model effect between RER and L%CO2 (F = 5.62, P = 0.03, R² = 0.20). Following main dietary interventions, no significant interactions (diet × day) were found. However, main diet effects were evident across all time-points assessed, highlighting significant differences for both L%CO2 and LI between LOW and HIGH conditions (P < 0.003). For L%CO2, this was particularly noted under fasted (4.35 ± 0.07 vs. 4.46 ± 0.06%, P = 0.001), pre-evening meal (4.35 ± 0.07 vs. 4.50 ± 0.06%, P < 0.001), and pre-bed time-points (4.51 ± 0.08 vs. 4.61 ± 0.06%, P = 0.005).
Conclusion
Our findings demonstrated that a portable, home-use metabolic device (Lumen) detected significantly increased expired %CO2 in response to a high-carbohydrate meal, and may be useful in tracking mean weekly changes to acute dietary carbohydrate modifications. Additional research is warranted to further determine the practical and clinical efficacy of the Lumen device in applied compared to laboratory settings.
... Next, in this study, the SNs emphasised training or sports periodisation plan. The athletes had specific and individual training periodisation programmes which integrate different types of training activities, specifically following their training calendars (Stellingwerff et al., 2019). Nutritional periodisation was then used to support training periodisation. ...
... Nutrition periodisation is defined as 'the planned, purposeful and strategic use of specific nutritional interventions to enhance the adaptations targeted by individual exercise sessions or periodic training' (Jeukendrup, 2017). Thus, understanding the athletes' training periodisation plans provides SNs with an overview or framework to match the nutrition strategies with training outcomes (Stellingwerff et al., 2019). ...
Background: It is considered that the implementation of nutrition care process (NCP) leads to more efficient and effective care, as well as enhancing the roles of dietetics and nutrition professionals in the clinical setting. However, little is known about the NCP being implemented in the sports nutrition setting to deliver nutrition care, especially in meal planning. Therefore, this study aims to identify the process that sports nutritionists (SNs) practice in meal planning to plan meals for athletes and identify the application of NCP. Methods: In-depth interviews, using semi-structured interview questions, were conducted with SNs employed at the National Sports Institute of Malaysia. Five SNs who managed different types of sports were recruited. The interviews were audio-recorded and transcribed verbatim. Data were entered into ATLAS.ti 8 and analysed using thematic analysis. Results: The following processes were identified: (i) collecting pertinent data, (ii) analysing the collected data, (iii) determining nutrition prescriptions, (iv) formulating goals and determining actions, (v) implementing actions and recommendations and (vi) monitoring. Conclusions: This study identified six general processes practiced by SNs in meal planning that comprised the NCP's interrelated steps, except nutrition diagnosis statement from the nutrition diagnosis step of the NCP. A comprehensive process and workflow can help sports dietitians or nutritionists to develop individualised meal plans that can improve athletes' nutritional status, adherence, health and sports performance. Abstract Original Article
... Next, in this study, the SNs emphasised training or sports periodisation plan. The athletes had specific and individual training periodisation programmes which integrate different types of training activities, specifically following their training calendars (Stellingwerff et al., 2019). Nutritional periodisation was then used to support training periodisation. ...
... Nutrition periodisation is defined as 'the planned, purposeful and strategic use of specific nutritional interventions to enhance the adaptations targeted by individual exercise sessions or periodic training' (Jeukendrup, 2017). Thus, understanding the athletes' training periodisation plans provides SNs with an overview or framework to match the nutrition strategies with training outcomes (Stellingwerff et al., 2019). ...
Background
It is considered that the implementation of nutrition care process (NCP) leads to more efficient and effective care, as well as enhancing the roles of dietetics and nutrition professionals in the clinical setting. However, little is known about the NCP being implemented in the sports nutrition setting to deliver nutrition care, especially in meal planning. Therefore, this study aims to identify the process that sports nutritionists (SNs) practice in meal planning to plan meals for athletes and identify the application of NCP.
Methods
In-depth interviews, using semi-structured interview questions, were conducted with SNs employed at the National Sports Institute of Malaysia. Five SNs who managed different types of sports were recruited. The interviews were audio-recorded and transcribed verbatim. Data were entered into ATLAS.ti 8 and analysed using thematic analysis.
Results
The following processes were identified: (i) collecting pertinent data, (ii) analysing the collected data, (iii) determining nutrition prescriptions, (iv) formulating goals and determining actions, (v) implementing actions and recommendations and (vi) monitoring.
Conclusions
This study identified six general processes practiced by SNs in meal planning that comprised the NCP's interrelated steps, except nutrition diagnosis statement from the nutrition diagnosis step of the NCP. A comprehensive process and workflow can help sports dietitians or nutritionists to develop individualised meal plans that can improve athletes' nutritional status, adherence, health and sports performance.
... Football players use both anaerobic and aerobic systems during training and matches and possess unique energy and nutrient needs depending on the nature and periods of training and competition [1,6]. As such, nutrition plays an important role in optimizing performance and maintaining overall health and training longevity throughout the season. ...
... A balanced diet plays a key role in proper recovery and optimal sports performance. Changes in food intake in response to certain periods of training are also of great importance within the so-called periodization of nutrition paradigm [6,9]. Properly periodized nutrition supports performance and energy levels throughout the competition season and/or training period [7,9,10]. ...
This is the first study to examine the nutritional status of professional Slovenian football players. This study aimed to analyze the dietary intake of elite football players during their preparation phase of the season and to investigate whether there is a relationship between energy and macronutrient intake with body composition and physical performance. Twenty-three footballers completed a three-day dietary and physical activity diary and underwent body composition measurements via bioelectrical impedance vector analysis (BIVA). Fifteen participants also took part in the Cooper treadmill test to assess their physical performance in correlation with their nutritional intake. Football players had an energy intake that was significantly too low for their needs, reflecting low energy availability. The average carbohydrate (CHO) intake was below the Union of European Football Associations (UEFA) recommendations, i.e., <4 g CHO/kg body weight (BW). Additionally, players had adequate intakes of protein and fat, and inadequate intakes of saturated fat, fiber, calcium and vitamin D. There was a positive correlation between protein intake and lean body mass. Additionally, a negative correlation was observed between body fat mass and carbohydrate intake as well as between performance with the percentage of energy intake from fat. Results of this study highlight what aspects of nutrition might be improved upon in professional football players to maximize performance, longevity and body composition of athletes, as well as the necessity of a nutritionist role in this process.
... It has to be underlined that educating athletes and coaches about nutrition and how to periodize diet to optimize training, exercise performance and recovery are key areas of involvement for sport dietitians and nutritionists. Taking into account the unique energy and biomechanical requirements, the triathlon is a discipline in which the implementation of strategic nutritional interventions at different times of the training and competition macrocycles seems to determine training, support adaptation, recovery and physical capacity [30]. ...
... However, for enhancement of athletic exercise performance and optimization of training adaptations, it is important to not only meet energy and macronutrients requirements but take care of overall nutrition (such as the intake of vitamins and minerals) [30]. ...
The triathlon is a demanding endurance multisport, which may strongly affect the nutritional status of athletes. The aim of this study was to find whether there are any differences in energy value and nutrient intake, body mass and body composition, aerobic performance and hair mineral status between training and competition periods and to assess whether there is a link between hair mineral content and physical capacity and nutrition. This observational study covered 20 triathletes aged 32 ± 7 years. The results of our study indicated performance improvement during the competition period (longer time to exhaustion (p = 0.025) and lower maximal oxygen uptake at the ventilatory threshold (%VO2max_VT; p = 0.047)). However, no differences were recorded in nutrition and body composition between two training vs. competition periods. There was a significant depletion in hair iron content during the competition period (p = 0.010). Furthermore, there were significant relationships between hair calcium content and absolute maximal oxygen uptake and %VO2max_VT during the training period. It is necessary to introduce nutritional education in the group of triathletes focused on exercise-oriented nutritional periodization following the requirements of the training and competition periods, thus preventing the risk of nutrient deficiencies.
... These findings are consistent with previous studies that have demonstrated the importance of NK in sports performance [39][40][41]. Moreover, these results underscore the need for greater nutritional education and support for athletes, especially in endurance sports where nutrition can have a significant impact on performance [42,43]. ...
This study investigates the physical characteristics, including anthropometry, somatotype, and body composition, of elite and non-elite orienteering athletes. Additionally, it explores the relationship between these physical characteristics and the athletes' nutrition knowledge and physical activity levels. Our findings indicate significant differences in body fat percentage, mesomorphy, ectomorphy, and nutrition knowledge scores between elite and non-elite athletes. These insights can be valuable for coaches and sports scientists aiming to enhance the performance of orienteering athletes.
The key contributions of our study include:
- Identification of physique characteristics specific to orienteering athletes.
- Comparison of these characteristics between elite and non-elite athletes.
- Analysis of the relationship between body composition, somatotype, physical activity levels, and nutrition knowledge.
... In contrast to carbohydrate loading, periodisation strategies, such as training with low carbohydrate availability, are employed to increase the efficiency of utilising available fuel sources during exercise [62,63]. Training with low carbohydrate availability potentially enhances fat oxidation rates and skeletal muscle signalling, which have been attributed to improvements in endurance running in both sexes [64]. ...
Global warming is attributed to an increased frequency of high ambient temperatures and humidity, elevating the prevalence of high-temperature-related illness and death. Evidence over recent decades highlights that tailored nutritional strategies are essential to improve performance and optimise health during acute and chronic exertional-heat exposure. Therefore, the purpose of this review is to discuss the efficacy of various nutritional strategies and ergogenic aids on responses during and following acute and chronic exertional-heat exposure. An outline is provided surrounding the application of various nutritional practices (e.g., carbohydrate loading, fluid replacement strategies) and ergogenic aids (e.g., caffeine, creatine, nitrate, tyrosine) to improve physiological, cognitive, and recovery responses to acute exertional-heat exposure. Additionally, this review will evaluate if the magnitude and time course of chronic heat adaptations can be modified with tailored supplementation practices. This review highlights that there is robust evidence for the use of certain ergogenic aids and nutritional strategies to improve performance and health outcomes during exertional-heat exposure. However, equivocal findings across studies appear dependent on factors such as exercise testing modality, duration, and intensity; outcome measures in relation to the ergogenic aid’s proposed mechanism of action; and sex-specific responses. Collectively, this review provides evidence-based recommendations and highlights areas for future research that have the potential to assist with prescribing specific nutritional strategies and ergogenic aids in populations frequently exercising in the heat. Future research is required to establish dose-, sex-, and exercise-modality-specific responses to various nutritional practices and ergogenic aid use for acute and chronic exertional-heat exposure.
... Sport of athletics has also been the central point of scientific consideration on a regular basis. [26]; Zaras N., Stasinaki A. N., Terzis G. [27] concerned the fields of defining athletes and exercisers, virtual athletes and e-sports, elite athletes, terminology, nutrition for athletics, biological determinants, and many others. Still, the English terms of athletics have not been explored enough. ...
... Indeed, Furber et al. (2022) recently demonstrated that participants' run time to exhaustion was consistently extended when microbial communities remained relatively unchanged throughout dietary challenges (high protein or high carbohydrate diets). Thus, athletes undergoing dietary periodization (Stellingwerff et al., 2019) or dietary supplementation protocols (Maughan et al., 2018), with the aim of improving athletic performance, would likely benefit from greater gut microbial stability and resilience. Although the DC group maintained an overall greater stability compared with the WC control group, we observed some slight compositional changes in the microbial community. ...
Objectives:
Dietary strategies to improve arachidonic acid:eicosapentaenoic acid (AA:EPA) ratios are of interest due to potential reductions in inflammation and oxidative stress following exercise. The aim of this study was to investigate the impact of a novel dietary intervention, that is, the ingestion of 30 g of dark chocolate, on blood lipid profiles and gut microbiota composition in elite male soccer players.
Methods:
Professional male soccer players were randomly assigned to the experimental group (DC) provided with 30 g of dark chocolate or to the control group (WC), provided with 30 g of white chocolate, for 30 days. Before and after intervention, blood, fecal sample, and anthropometry data were collected. For each outcome, two-way repeated-measure analysis of variance was used to identify differences between baseline and endpoint (Week 4), considering treatment (dark chocolate, white chocolate) as intersubjects' factors. Metagenomic analysis was performed following the general guidelines, which relies on the bioBakery computational environment.
Results:
DC group showed increased plasma polyphenols (from 154.7 ± 18.6 μg gallic acid equivalents/ml to 185.11 ± 57.6 μg gallic acid equivalents/ml, Δ pre vs. post = +30.41 ± 21.50) and significant improvements in lipid profiles: total cholesterol (Δ -32.47 ± 17.18 mg/dl DC vs. Δ -2.84 ± 6.25 mg/dl WC, Time × Treatment interaction p < .001), triglycerides (Δ -6.32 ± 4.96 mg/dl DC vs. Δ -0.42 ± 6.47 mg/dl WC, Time × Treatment interaction p < .001), low-density lipoprotein (Δ -18.42 ± 17.13 mg/dl vs. Δ -2.05 ± 5.19 mg/dl WC, Time × Treatment interaction p < .001), AA/EPA ratio (Δ -5.26 ± 2.35; -54.1% DC vs. Δ -0.47 ± 0.73, -6.41% WC, Time × Treatment interaction p < .001) compared with WC group. In addition, 4 weeks of intervention showed a significant increase in high-density lipoprotein concentration in DC group (Δ + 3.26 ± 4.49 mg/dl DC vs. Δ -0.79 ± 5.12 mg/dl WC). Microbial communities in the DC group maintained a slightly higher microbial stability over time (exhibiting lower within-subject community dissimilarity).
Conclusion:
Ingesting 30 g of dark chocolate over 4 weeks positively improved AA:EPA ratio and maintained gut microbial stability. Dark chocolate ingestion represents an effective nutritional strategy to improve blood lipid profiles in professional soccer players. What Are the Findings? Ingesting 30 g of dark chocolate for 4 weeks positively influences blood lipid AA: EPA ratio while maintaining gut microbial stability. What This Study Adds? Dietary intake of specific foods such as dark chocolate represents an alternative strategy to support the health and recovery of elite soccer players. What Impact Might This Have on Clinical Practice in the Future? From a clinical and translational perspective, dark chocolate ingestion positively modulates favorable blood lipid profiles and polyunsaturated fatty acid metabolism while maintaining gut microbial stability. Dark chocolate ingestion may be considered as an effective nutritional strategy in elite sport environments during periods of high-intensity training and congested competitions. Further research is required to determine functional outcomes associated with the observed improvements in blood lipid profiles.
... The manipulation of carbohydrate (CHO) intake to support adaptations to endurance capacity is a common consideration for athletes although there remains considerable debate regarding its practicality and efficacy. Key opinion leaders are divided, with some stating consensus for adaptation to a low CHO diet (Noakes et al., 2014;Phinney et al., 1983;Prins et al., 2023;Volek et al., 2015), while others being more in favour of a periodised approach (Impey et al., 2018;Jeukendrup, 2017;Stellingwerff et al., 2019). A periodised approach ensures various components of the athlete's diet, including CHO intake, are closely aligned with the goal or desired training outcome based upon factors including training volume, training intensity, training session objectives and race specific strategies. ...
There are conflicting reports both within the lay media and scientific literature regarding the use and benefit of dietary practices that aim to reduce CHO intake in endurance athletes. This study aimed to determine the prevalence of intentional reduction of CHO intake and fasted training in elite endurance‐based athletes using a semi‐quantitative questionnaire. Bone is a nutritionally modulated tissue; therefore, this study also aimed to explore if these dietary practices are potentially associated with bone injury incidence. The reported reduction of CHO intake was prevalent (28%) with the primary motivation being maintenance or manipulation of body composition. However, discrepancies in athletes' awareness of CHO intake were identified providing a potential avenue of intervention especially within applied practice. The use of fasted training was more prevalent (38%) with athletes using this practice for both body composition manipulation and promoting a desired adaptive response. Forty‐four per cent of participants had suffered a radiographically confirmed bone injury at some point in their career. There was no association between reduction in CHO intake and bone injury incidence; however, the incidence of bone injury was 1.61 times higher in those who currently use fasted training compared to those who have never used it or who have used it in the past. Although a direct causal link between these dietary practices and the incidence of bone injury cannot be drawn, it provides robust justification for future investigations of the potential mechanisms that could explain this finding.
... Nutritional practices can also influence bone health, and the effects of various interventions on BMD and BTMs have been investigated (Palacios, 2006;Sale & Elliott-Sale, 2019). Energy and macronutrient (particularly carbohydrate) demands of athletes vary between and within days and this is a key driver of dietary intake, such that a degree of periodization in energy and carbohydrate intake is typically recommended (Stellingwerff et al., 2019). Planned and unplanned bouts of low energy availability (LEA) and low-carbohydrate diets (with or without high fat) have been observed in various groups of athletes; thus, the bone response has been of specific interest. ...
It is important for athlete and public health that we continue to develop our understanding of the effects of exercise and nutrition on bone health. Bone turnover markers (BTMs) offer an opportunity to accelerate the progression of bone research by revealing a bone response to exercise and nutrition stimuli far more rapidly than current bone imaging techniques. However, the association between short-term change in the concentration of BTMs and long-term bone health remains ambiguous. Several other limitations also complicate the translation of acute BTM data to applied practice. Importantly, several incongruencies exist between the effects of exercise and nutrition stimuli on short-term change in BTM concentration compared with long-term bone structural outcomes to similar stimuli. There are many potential explanations for these inconsistencies, including that short-term study designs fail to encompass a full remodeling cycle. The current article presents the opinion that data from relatively acute studies measuring BTMs may not be able to reliably inform applied practice aiming to optimize bone health. There are important factors to consider when interpreting or translating BTM data and these are discussed.
... In the context of research on nutrition's influence on badminton athletes' performance, various theories and models have been developed to understand the relationship between nutrient intake and physical performance enhancement. One frequently cited model is the Nutrient Periodisation Model, which suggests that athletes' nutritional intake should be adjusted based on their training cycle to maximize performance and recovery (Stellingwerff, Morton, & Burke, 2019). This model recognizes that athletes' nutritional needs change depending on their training phase, whether the preparation, competition, or recovery phase. ...
Background and Goal of Study: Athletic performance results from a complex interaction between training, genetics and nutritional intake. In sports such as badminton, which demand endurance, speed and strength, nutrition plays a crucial role in supporting performance and recovery. Although nutrition is recognised as an important factor, there is limited research on the specific effects of nutrition on badminton athlete performance. This study aims to systematically analyse the existing literature on the influence of nutrition on badminton athlete performance, focusing on macronutrients, micronutrients and supplementation. Materials and Methods: This study used a systematic review approach, following PRISMA guidelines. Databases such as PubMed, Scopus, and Web of Science were reviewed for articles published from 2010 to 2023, using keywords related to nutrition and badminton. Studies that met the inclusion criteria were evaluated based on the research design, population, type of nutrition intervention, and performance measures used. Data were extracted and analysed qualitatively. Results: Of the 130 articles identified, 61 met the inclusion criteria. Findings showed that optimal carbohydrate intake, adequate hydration and nutritional timing significantly improved stamina and recovery. Supplementation with creatine and beta-alanine was also shown to improve strength and endurance performance. However, the effects of micronutrients such as vitamins and minerals were more variable and dependent on the individual's nutritional status before the intervention. Conclusion: Nutrition plays a vital role in supporting the performance of badminton athletes. Carbohydrates, adequate hydration, and certain supplements such as creatine and beta-alanine can improve performance. However, nutritional recommendations should be individualised based on the athlete's needs and goals. Further research is needed to examine micronutrient-specific effects and personalised nutrition strategies in badminton. Keywords: Nutrition, Badminton Athlete, Systematic Review.
... Performance (running distance) is positively correlated with energy intake and negatively with fluid intake, this means that as marathon runners energy needs before the race become important (Lavoué et al., 2020). Athlete performance and training adaptation are closely related to adequate and periodic intake of energy and macronutrients (Phillips, 2012;Stellingwerff, Morton, et al., 2019). Carbohydrates (CHO) are the superior macronutrients that fuel high-intensity exercise and allow athletes to train and compete (Moore et al., 2021). ...
This research is a literature study that aims to explore the relationship between carbohydrate consumption and athlete performance and health, especially female athletes who run long distances. This study uses the method of literature study or literature review using secondary data from scientific journal articles. Article searches are conducted through various platforms such as Google Scholar, EBSCO, ScienceDirect, and Proquest using keywords related to carbohydrate consumption in female long-distance runners. The inclusion criterion for articles is that they must be scientific journal research articles conducted in the UK with the main subject female athletes long-distance runners and the topic relates to carbohydrates. Articles that meet these criteria are then further analyzed Through an analysis of 8 scientific journal articles, it was concluded that carbohydrate intake has a crucial role in improving athletes' performance and endurance, as well as preventing the risk of low energy availability that can have a negative impact on health. In addition, research also highlights the need for adjustments in carbohydrate intake based on environment and stress to maximize athletes' training and recovery abilities. These findings affirm the importance of designing a balanced diet of carbohydrates and protein to achieve the desired results in improving athlete performance and supporting healthy weight loss. This study provides a deep understanding of the importance of carbohydrate intake in supporting the performance and health of female long-distance runners, and emphasizes the need for more inclusive research to develop better nutritional interventions.
... As highlighted above, elite fencers' training is structured around periods, where the composition of exercise is strategically modified within a series of cycles. Similarly, dietary intake and nutrition strategies should be consistently adapted to the continuously evolving training program, aligning with the micro-, meso-, and macro-cycle training, all aimed at ultimately achieving long-term objectives [15]. Strategies for nutrition during competitions could span pre-event, in-event, and inter-event eating, all carefully devised to meet the requirements for fuel and fluid replenishment [16]. ...
The aim of this narrative review is to create a comprehensive, innovative, and pragmatic resource to guide elite fencers and coaches in making strategic nutritional choices to enhance performance and facilitate recovery. The literature review identified only 12 articles specifically addressing the topic of nutrition for fencers. Thus, the recommendations provided in this review derive also from articles dealing with similar sports, such as martial arts, and from investigations with European elite fencers and their coaches. For elite fencers, it is suggested to consume daily 7–11 g/kg of body weight (BW) of carbohydrates and 1.5–2 g/kg of BW of proteins and allocate 25% to 30% of the total energy intake to essential fats, with a specific focus on omega-3 fatty acids. The timing of meals, ideally within one hour after exertion, plays a pivotal role in restoring glycogen reserves and preventing injuries. The intake of leucine, creatine, omega-3, collagen, and vitamins C and D is proposed as a strategy for injury recovery. It is worth acknowledging that even when personalized plans are provided, implementation can be challenging, especially during competitions and training camps.
... For a more detailed and validated tool, we would advocate incorporating the updated IOC REDs CAT2 tool. 41 ...
Relative energy deficiency in sport (REDs) is a potentially severe, challenging, broad-spectrum syndrome with potential negative health and performance outcomes. The numerous research publications and International Olympic Committee consensus statements relating to REDs testify to the challenges faced in early identification or screening, diagnosis and management. Like sport, dance, in its simplest form, can be identified as an activity resulting in physiological energy demands and, as such, requires appropriate energy availability concerning energy expenditures. However, the specificity of physiological and psychological demands in dance must be considered when considering REDs. An environment where physical activity can exceed 30 hours per week and where culture may instil a value that thinness is required puts dancers at increased risk for REDs. The purpose of this study was to provide dance-specific guidance dance on this complex condition. An RAND/UCLA Delphi Panel method with nominal group technique was used to review the literature from REDs to evaluate how it may relate to dance. In addition to the EP, which was assembled from a multidisciplinary background with expertise in REDs and multiple genres of dance, six focus groups were commissioned. Four of the focus groups were drawn from the EP members and two additional focus groups formed by dancers and artistic leaders. These panels were used to guide the development of a RED-D diagnosis pathway, management plan and risk stratification and return to dance pathway. The dance-specific pathways are designed to be a practical tool for guiding and supporting clinicians managing RED-D. Furthermore, this paper represents an important focus of this area in dance and serves to stimulate discussion and further research within the sector.
... Sporcuların kişisel periyodik antrenman planlarına uygun adaptasyonları geliştirmek veya uzun süreli performansı artırmak için belirli beslenme müdahalelerinin planlı, amaçlı ve stratejik planlanmasını belirtmek üzere "Beslenme Periyodizasyonu" veya "Periyodize Beslenme" terimleri kullanılmıştır (Jeukendrup, 2017a). Beslenme periyodizasyonunun temel amacı; uzun, orta ve kısa süreli antrenman periyotlarına adaptasyonu artırmak için uygun enerji ve makrobesin ögesi alımını planlayarak, kısa ve uzun vadeli performans kazandırmaktır (Stellingwerff, Morton, Burke, 2019), (Hartmann ve ark. 2015). ...
Müsabaka sporcularının enerji ve besin ögesi alımları; sağlık durumlarını korumak, spor performanslarını geliştirmek, toparlanmalarını hızlandırmak, yaralanma ve sakatlıkları önlemek için önemlidir. Bu derlemede; sporcuların enerji, makro ve mikrobesin ögesi alımlarının sporcunun sağlığı ve performansına etkilerinin sistematik olarak incelenmesi amaçlanmıştır. Bu doğrultuda, 2012-2023 yılları arasında yayınlanan 31 makale seçilmiş, sporcuların enerji, makro ve mikrobesin ögesi gereksinimleri olarak üç başlık oluşturulmuştur. Araştırma sonuçları hem kadın hem erkek sporcular için kullanılabilir enerjinin önemini vurgulamış, artan enerji harcaması için gerekli enerji alımını sağlamanın önemini göstermiştir. Enerji ve makrobesin ögesi alımının beslenme periyodizasyonu ile sağlanmasının spor performansını destekleyebileceği gösterilmiştir. Antrenman veya müsabaka dönemlerine göre önerilen makro ve mikrobesin ögelerinin sporcunun performans belirteçlerini desteklediği, ancak önerilenin üzerinde alımın performans üzerinde önemli bir etkisi olmadığının üzerinde durulmuştur. Doğru planlanan bir diyet ile D vitamini, antioksidan vitaminler, demir, kalsiyum, sodyum, magnezyum gibi mikrobesin ögelerinin gereksiniminin karşılanabileceği, besin desteği olarak alımının ise spor performansına etkilerini görebilmek için daha fazla çalışma yapılması gerekliliği ortaya konmuştur. Bu derlemede; sporcular için güncel temel konular ele alınmış, sporcular, spor diyetisyenleri ve klinisyenler için bir rehber oluşturulmuştur. Anahtar Kelimeler: spor beslenmesi, enerji alımı, makrobesin ögesi alımı, mikrobesin ögesi alımı, spor performansı
... Due to this, malate produces antihypoxic, anti-ischemic, cardioprotective and actoprotective effects. Malate is administered for asthenic syndrome, emotional exhaustion, diabetic asthenia, asthenic syndrome in athletes due to prolonged physical exertion; severe fatigue, overwork; muscle cramps; sexual asthenia; alcohol withdrawal syndrome; pain after exercise; after heavy physical exertion, which causes overload of the body [56]; to alleviate myalgia in athletes after intense training and to correct acidosis [22]. Malate is available as Magnesium malate, Calcium malate, and Citrulline malate. ...
Aim. The purpose of this study was to conduct an up-to-date semantic analysis of the results of our own research and literature data on the medical and pharmacological characteristics of metabolites, metabolitotropic agents and nutritional supplements, the peculiarities of their use in sports practice and sports medicine. Materials and methods. This study used bibliosemantic, analytical, logical, and generalization methods. The life sciences and biomedical information bibliographic databases MEDLINE, EMBASE, Medline (PubMed), Web of Science, and Cochrane Central were searched to find publications in English that matched the research keywords. The authors carried out an independent search and selection of articles, assessment of the quality of the data, compliance of the presentation and interpretation with the main idea of the study, with the formation of the final list of references. Results. Based on the analysis of modern literature data and the results of our own studies, a generalized medical and pharmacological characteristic of metabolite agents, metabolitotropic drugs and nutritional supplements that can influence the main and compensatory mechanisms of macroergic phosphates production under the influence of physical activity is presented. The mechanisms of action, indications for use and main side effects of drugs and food additives based on ATP, malate, succinate, citrate, pyruvate, carnitine, carnosine, etc. are presented. Conclusions. Semantic analysis data indicate that an urgent problem for sports medicine physicians and pharmacologists is the development and use of metabolites, metabolitotropic agents and nutritional supplements, as well as approaches to their rational combination to improve energy metabolism, replenish ATP reserves in the body that will help ensure the intensity muscular activity and simultaneously protect target organs.
... In athletes, nutritional assessment should be achieved according to the periodization of training [47,48]. Athletes follow specific training patterns during the "in" and "off" season, as well as during the pre-and post-competition periods. ...
The aim of this study was to conduct a systematic review and meta-analysis of differences in energy and macronutrient intakes between young athletes and non-athletes, considering age, gender and sport characteristics. The study included original research articles that compared energy and macronutrient intakes of 8 to 18-year-old athletes to non-athletes. Mean difference (MD) meta-analyses were performed to quantify energy and macronutrient intake differences between athletes and non-athletes. Eighteen observational studies were included. Results revealed that the energy and carbohydrate consumption of athletes was higher than that of non-athletes (MD=4.65kcal/kg/d, p<0.01 and MD=1.65% of total energy intake, p<0.01, respectively). Subgroup analyses revealed a significant effect of total training time on the observed mean differences between athletes and non-athletes. As practice time increased, the differences between athletes and non-athletes increased for carbohydrate and decreased for protein. Sport type analysis revealed a higher protein intake by mixed sport athletes compared to endurance and power sports. Analyses also indicated an age effect: the older the athletes, the smaller the differences between athletes and non-athletes for energy intake. However, the methods used to match groups and estimate dietary intakes forced us to moderate the results. More rigorous research methods are needed to define the dietary intakes of athletes and non-athletes.
... One of the most well-known strategies affecting different body systems is nutrition and nutritional supplements. Although the existing knowledge about how nutrition affects the performance of the body and athletes is still expanding, it is well known that nutrition can help improve sports performance through its acute and chronic effects [6,7]. Interestingly, some supplements with a quick effect on neuromuscular, metabolism, and cardiovascular function lead to the improvement of technical or physical performance of athletes [8,9]. ...
Background:
The improvement of performance and skill indices of volleyball players can affect their success rate. Therefore, the present study aimed to evaluate the effects of acute caffeine supplementation of varied doses on collegiate volleyball players' specific performance and skills.
Method:
This research was a randomized, double-blind, crossover design study in which 15 male volleyball players aged 18 to 25 years participated voluntarily. Participants were randomly placed in three different conditions, including 3 mg of caffeine per kilogram of body weight (C3), 6 mg of caffeine per kilogram of body weight (C6), and a placebo (PLA) with a one-week wash-out period between exercise trials. The supplement was taken 60 min before each exercise session. Ball throwing, hand movement speed, agility, Sargent's jump and handgrip, and attacking and serving skill tests were measured and analyzed to check the performance and skill of the volleyball players.
Results:
This study showed a significant increase in agility test in C6 compared with the PLA condition (p = 0.02). Additionally, there was a significant improvement in Sargent's jump in C6 compared with PLA (p = 0.00) and C6 compared with the C3 condition (p = 0.00). Also, attacking skill significantly increased in C3 compared with PLA (p = 0.00) and C6 compared with the PLA condition (p = 0.00). In addition, there was a significant increase in serving skill for C6 compared with PLA (p = 0.00) and C3 (p = 0.00). However, there were no significant differences in hand movement speed (p = 0.06), left handgrip (p = 0.85), right handgrip (p = 0.47), or medicine ball throwing (p = 0.22) between the three conditions.
Conclusions:
In conclusion, the findings of the current study suggested that a higher dose of caffeine compared with a lower dose may be more effective in movements requiring lower-body explosive power and the ability to change direction. Also, according to the findings, it seems that caffeine can lead to the improvement of complex skills, such as serving and attacking in volleyball.
... Football players engage mutually anaerobic and aerobic systems simultaneously during training sessions and matches, with their specific energy and nutritional needs varying based on the category and phases of training and competition [5]. As a result, nutrition plays a fundamental role in performance optimization and sustaining overall health and training resilience during the season [6]. ...
This study represents the first to examine the nutritional status of Moroccan football players. The aim of this research is to assess the energy and macronutrient intake of professional players from a club competing in the Moroccan professional league "Botola-Pro." Moreover, the study tries to find the potential correlation between nutritional intake and physical performance. A total of 27 professional players participated in a seven consecutive-day study, during a microcycle of the preseason period. The dietary intake was evaluated using the self-reported, complemented by a 24-hour recall. The InBody 120 bioelectrical impedance was employed for assessing body composition measurements, while the Yo-Yo test was utilized to evaluate physical performance; which estimates the maximal oxygen consumption level (VO2max). Among these players, their protein intake levels aligned with recommendations (1.6 to 2.2 g/kg of Body Mass). On the other hand, fat intake slightly surpassed the recommended values. However, carbohydrate intake was relatively subdued compared to recommendations of the Union of European Football Associations (UEFA) in the pre-season training phase. A positive correlation was observed (P-value of < 0.001 and R=0.831) between carbohydrate intake and the measure of VO2max. This suggests that an increase in carbohydrate consumption is associated with enhanced performance, especially within the range of 6 to 8 g/kg BM per day. Conversely, a negative correlation was identified (P-value of < 0.01 and R= − 0.847) between the percentage of dietary fat and the VO2max. The findings of this study highlight areas of nutrition that could be enhanced among professional football players to optimize their performance. In effect, nutritional education is necessary for this category of athletes. Thus, an individual care approach is strongly recommended.
... Sportistima i aktivnim pojedincima potrebna je veća pomoć kada planiraju GF ishranu kod kuće ili na putu kako bi sprečili moguće nedostatke hranljivih materija u organizmu. Tada se često preporučuju i suplementi kao način nadoknade potrebnih ugljenih hidrata [4,11]. ...
"Gluten-free" is now becoming a catchphrase that has spread rapidly over the past few years and is often used in food advertising to entice individual consumers to join the diet of prominent sports figures. Certainly, a gluten-free diet for some people is a necessity in case of illness, but very often it is a product of striving for a healthier and different way of life carried out through nutrition. This way of eating is often represented by professional athletes, who have to compensate for their increased need for carbohydrates in a different way, when the regime of training and activities is completely adapted to a gluten-free diet. In this way, eliminating gluten quickly becomes a way of life after a short period of time. It is essential to note that a gluten-free diet is not necessary for a "healthy" diet -there is a much more efficient way to achieve such a style of eating, but still, you should know that some people must avoid gluten if they have celiac disease or an intolerance ie. gluten sensitivity. How and in what way a gluten-free diet affects sports activities, as well as what training method is recommended with such a diet, through a research review of the literature and previous research, the work follows the general indicators of what gluten is and how its exclusion from the diet manifests itself in sports activities.
... Yet, there is little evidence on which type of exercise (interval or continuous training), is most efficient with respect to EE. This is crucial in several respects: 1) EE is important for body weight management [22,23] 2) high daily EE is associated with a reduced risk of chronic diseases and mortality [24,25], 3) EE management is critical for high-performance athletes (e.g., training periodization [26,27], energy availability [28], avoiding relative energy deficiency [29]). ...
Background:
A sedentary lifestyle with low energy expenditure (EE) is associated with chronic diseases and mortality. Barriers such as "lack of time" or "lack of motivation" are common reasons why physical exercise is neglected in the general population. To optimize EE in the time available, time-efficient but also enjoyable types of exercise are required. We therefore used an isocaloric approach to systematically investigate the effects of six different endurance exercise modalities on metabolic, mechanical, cardiorespiratory, and subjective variables in relation to biological sex and physical fitness.
Methods:
Out of 104, 92 healthy participants (21 recreationally trained and 18 trained females, 25 recreationally trained and 28 trained males) were subjected to physiological exercise testing to determine the exercise intensities for six exercise modalities, i.e., three different high-intensity interval training (HIIT) protocols (5 × 4 min, 15 × 1 min, 30 × 30 sec intervals), threshold (THR), speed endurance production (SEP), and low-intensity training (LIT). One of three HIIT sessions served as the reference for the subsequent isocaloric exercise modalities which were completed in randomized order. Metabolic and mechanical variables, i.e., EE during exercise, time to isocaloric EE (Tiso), relative and absolute fat contribution, post-exercise oxygen consumption (EPOC), mechanical energy, as well as cardiorespiratory and subjective variables, i.e., heart rate, oxygen uptake response, rating of perceived exertion, and enjoyment were assessed. Data were analyzed using a 6 × 2 × 2 repeated-measures ANOVA.
Results:
All three versions of HIIT and THR achieved the same EE during exercise for the same training duration. We found that LIT had a 1.6-fold (p < 0.001) and SEP a 1.3-fold (p < 0.001) longer Tiso compared to HIIT with no effects of biological sex (p = 0.42, pη2 = 0.01) or physical fitness (p = 0.09, pη2 = 0.04). There was a main effect of exercise modality on EPOC (p < 0.001, pη2 = 0.76) with highest values for HIIT 30 × 30 (p = 0.032) and lowest for LIT (p < 0.001). The highest relative and absolute amounts of fatty acids were measured during LIT (p < 0.001), and the lowest values were obtained during HIIT modalities. HIIT 30 × 30 was the most enjoyable version of HIIT (p = 0.007), while THR was the least enjoyable exercise modality (p = 0.008).
Conclusion:
HIIT modalities are time-saving and enjoyable, regardless of sex and physical fitness. The results illustrate the relationship between exercise modality and metabolic, physiological, and subjective responses, and are thus of great interest to healthy individuals seeking time-saving and enjoyable exercise options.
... In nutrition and exercise prescription for athletes, an amalgamation of multiple "train low" strategies appears optimal as it can be tailored to individual requirements throughout a training cycle (Stellingwerf, 2012;Stellingwerff, Morton and Burke, 2019). A popular example of this approach is the so-called "sleep low-train low" strategy, which includes three different training-nutrition interventions: high-intensity training (HIT) in the evening to deplete glycogen stores, followed by low carbohydrate availability overnight (i.e., sleeping low), and low-intensity training (LIT) the following morning under conditions of low muscle glycogen/carbohydrate availability. ...
Endurance athletes have traditionally been advised to consume high carbohydrate intake before, during and after exercise to support high training loads and facilitate recovery. Accumulating evidence suggests periodically training with low carbohydrate availability, termed “train-low”, augments skeletal oxidative adaptations. Comparably, to account for increased carbohydrate utilisation during exercise in hot environmental conditions, nutritional guidelines advocate high carbohydrate intake. Recent evidence suggests heat stress induces oxidative adaptation in skeletal muscle, augmenting mitochondrial adaptation during endurance training. This thesis aimed to assess the efficacy of training with reduced carbohydrate and the impact of elevated ambient temperatures on performance and metabolism. Chapter 4 demonstrated 3 weeks of Sleep Low-Train Low (SL-TL) improves performance when prescribed and completed remotely. Chapter 5 implemented SL-TL in hot and temperate conditions, confirming SL-TL improves performance and substrate metabolism, whilst additional heat stress failed to enhance performance in hot and temperate conditions following the intervention. Chapters 6 and 7 optimised and implemented a novel in vitro skeletal muscle exercise model combining electrical pulse stimulation and heat stress. Metabolomics analysis revealed an ‘exercise-induced metabolic response, with no direct metabolomic impact of heat stress. Chapter 8 characterised the systemic metabolomic response to acute exercise in the heat following SL-TL and heat stress intervention revealing distinct metabolic signatures associated with exercise under heat stress.
In summary, this thesis provides data supporting the application of the SL-TL strategy during endurance training to augment adaptation. Data also highlights the impact of exercise, environmental temperature and substrate availability on skeletal muscle metabolism and the systemic metabolome. Together, these data provide practical support for the efficacy of the SL-TL strategy to improve performance and adaptation whilst casting doubt on the utility of this approach in hot environments in endurance-trained athletes.
... Energy availability is defined as the amount of energy that is accessible to fuel bodily processes after the demands of exercise training have been met (Loucks et al., 2011). Brief exposure to planned low energy availability within a periodized training program may bring about beneficial outcomes, such as reducing unnecessary body fat or increasing metabolic efficiency, which in turn may support attainment of performance goals Stellingwerff et al., 2019), however more severe and prolonged low energy availability can lead to negative health consequences (Areta et al., 2021), including disrupted reproductive function, compromised bone health and increased injury risk (Mountjoy et al., 2018;Nattiv et al., 2007). Recently our group discussed the concept of LEA from a life history perspective and in light of the trade-offs that may occur when energy availability is low (Oliveira-Junior et al., 2022;Shirley et al., 2022). ...
Exercise physiologists and evolutionary biologists share a research interest in determining patterns of energy allocation during times of acute or chronic energetic scarcity.. Within sport and exercise science, this information has important implications for athlete health and performance. For evolutionary biologists, this would shed new light on our adaptive capabilities as a phenotypically plastic species. In recent years, evolutionary biologists have begun recruiting athletes as study participants and using contemporary sports as a model for studying evolution. This approach, known as human athletic palaeobiology, has identified ultra-endurance events as a valuable experimental model to investigate patterns of energy allocation during conditions of elevated energy demand, which are generally accompanied by an energy deficit. This energetic stress provokes detectable functional trade-offs in energy allocation between physiological processes. Early results from this modelsuggest thatlimited resources are preferentially allocated to processes which could be considered to confer the greatest immediate survival advantage (including immune and cognitive function). This aligns with evolutionary perspectives regarding energetic trade-offs during periods of acute and chronic energetic scarcity. Here, we discuss energy allocation patterns during periods of energetic stress as an area of shared interest between exercise physiology and evolutionary biology. We propose that, by addressing the ultimate "why" questions, namely why certain traits were selected for during the human evolutionary journey, an evolutionary perspective can complement the exercise physiology literature and provide a deeper insight of the reasons underpinning the body's physiological response to conditions of energetic stress.
... Functional foods included in nutrition plans of professional athletes have a positive effect on health, enhance performance, reduce the risk of injuries, and enhance recovery. A contemporary sports nutrition supplement is an outcome of extensive research in genomics, metabolomics, bionanotechnology, and medicine, along with the thoughtful application of science-intensive technologies [2,[5][6][7][8][9][10][11][12][13][14]. ...
The present study discusses foods for professional athletes since sports nutrition is the foundation of effective performance. A dietary supplement complex designed for ski orienteers, swimmers, road cyclists, and biathletes is described. The composition of the dietary supplement complex with directed influence on metabolic processes, intensity, and training load is given. All the ingredients for this complex are selected, taking into account their synergistic effect and safety. The manufacturing process, with its gentle process conditions like granulation at 40 °C, drying at 60 °C, and a relatively short manufacturing time, ensures the safety of biologically active ingredients and their functional properties. The manufacturing company is the International Organization for Standardization (ISO) certified and meets the General Manufacturing Practice (GMP) requirements. The clinical trials were undertaken to evaluate the efficacy of the dietary supplement complex. The findings indicate increased adaptation to training, enhanced recovery, and balanced emotional state. The benefits of adding the dietary supplement complex to eating plans of sportsmen are listed.
... Despite this desire, the majority of research efforts in sports nutrition to date have focused on increasing our understanding of how nutrient availability modulates metabolism and physiology (Jonvik et al., 2022). These efforts have led to the growth and evolvement of strategies such as nutritional periodization which has rapidly become a hot topic in sports nutrition literature (Jeukendrup, 2017;Burke and Hawley, 2018;Stellingwerff et al., 2019b). However, the optimal delivery of such a nuanced intervention that requires a practitioner to be adequately trained in the physiology of training has yet to be explored. ...
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.
... Hemoglobin can assess the physical function status of athletes and reflect the iron deficiency status in the body. 9 It is the basic index to evaluate an athlete's nutrition and health status. Its main function is to act as a carrier for red blood cells to transport oxygen and CO 2 and maintain blood acid-base balance and a constant pH value. ...
Introduction
This paper studies physiological and biochemical indicators in the systematic training of sprinters. This paper analyzes the data measured during the athletes’ training process and studies the detailed data of their physical functions.
Objective
This study aimed to find a link between exercise data and biochemical indicator data in sprinter athletes. By analyzing the data from this article, the researchers were able to find the optimal training program for the athletes.
Methods
High-intensity aerobic training tests were performed with statistical analysis of various physiological and biochemical indicators.
Results
Hemoglobin data were shown to be highly sensitive to intensity. The researchers found that long-term high-load training in athletes can lead to physical fatigue. This fatigue production is positively correlated with the intensity of the training load.
Conclusion
There is a strong positive correlation between biochemical and physiological indicators on performance levels in sprinter athletes. Evidence Level II; Therapeutic Studies – Investigating the results.
Track and field; Athlete; Physiological monitoring; Sports
Introducción:
La composición corporal es un indicador fundamental para definir el estado nutricional del corredor.
Objetivo:
El estudio tuvo como objetivo evaluar los efectos de la intervención de periodización nutricional en la composición corporal de corredores juveniles djiboutianos de élite en distancia media.
Materiales y métodos:
La muestra fue de 22 corredores masculinos, en edades comprendidas entre 16 y 18 años. Para la valoración, se diseñó un experimento constituido por 11 sujetos en el grupo control y 11 en el experimental. Como mediciones antropométricas se tomaron el peso, estatura y seis panículos adiposos para evaluar el porcentaje de grasa, índices de adiposidad, índice de masa corporal y el de sustancia corporal activa pues, para llevar el seguimiento de la intervención propuesta, se realizó una entrevista de recordatorio 24 horas de siete días.
Resultados:
Se diseñó una dieta periodizada, con la manipulación de los carbohidratos. La periodización nutricional con alta y baja ingesta de carbohidratos durante 12 semanas disminuyó significativamente (p< 0,05) el porcentaje de grasa, sin alterar el peso corporal ni el índice de sustancia corporal activa en los corredores djiboutianos de media distancia juveniles del grupo experimental.
Conclusiones:
Los resultados expuestos contribuyen a mejorar el control biomédico del entrenamiento en los corredores de élite juveniles de distancia media en Djibouti, ya que existían limitaciones de datos sobre su composición corporal y el efecto que pudiera tener la nutrición periodizada sobre esos indicadores
Palabras clave : Periodización nutricional; Composición corporal; Corredores; Media distancia
Both training and dietary practices used by athletes greatly vary. Current sports nutrition guidelines promote dietary manipulation of energy-yielding nutrients specific to the period of training. The study explores the ad libitum nutrition practices of four healthy adult recreational athletes during a 2-week cycling training camp (~100 km·d-1, ~240 min·d-1) with particular attention to the current sports nutrition recommendations. Based on evidence-based guidelines, peri-exercise carbohydrate (CHO) and protein (PRO) intake periodization cut-off levels were set for athletes. Training days were categorized as hard (HARD, two training units/day), middle (MID, one training unit/day), and easy (LOW, no training). Fourteen-day diet records were used and analyzed by nutritional software for energy intake (EI), carbohydrate (CHO), and protein (PRO) intake. Relative daily EI of 78.6±4.5, 73.3±6.4, 75.4±8.2 kcal·kg·d-1, and CHO 8.9±0.8, 7.8±1.0, 8.2±1.5 g·kg1 intakes were not different in HARD, MID and LOW days, respectively. The mean daily EI was 1.3× higher than the predicted total daily energy expenditure, irrespective of the training day category, resulting in ~500 kcal·d-1 energy surplus. In the 2h post-exercise period, PRO intake exceeded the current recommendations 4.6-fold, and CHO intake was significantly lower after a second training session on HARD days (0.7 g·kg·h-1) than a recommendation (1.2 g·kg·h-1). Mean in-exercise CHO intake (~11.5 g·h-1) was significantly under the moderate 30 g·h-1 recommendation. In conclusion, the dietary behaviours of recreational athletes are not consistent with current sports nutrition periodization guidelines. Energy intake throughout the training camp led to positive energy balance being highest on non-training days. Daily or during and post-exercise CHO and PRO intakes were not adjusted to the training sessions' volume, intensity, or duration.
Introduction
Sport climbing has gained increased scientific attention, including studies investigating the dietary habits and nutritional requirements of climbers; however, significant gaps in the literature remain. An assessment of nutritional knowledge, weight loss for competition, and supplement use has not been previously reported in senior competition climbing athletes.
Methods
Fifty climbers (26 male, 24 female; BMI 21.6 ± 1.9; 23.7 ± 5.2 years) participated in the study. Participants answered a 72-item questionnaire, comprised of demographic data and three main sections to assess general and sports nutrition knowledge, weight loss strategies, and supplement use.
Results
The mean nutrition knowledge score was ‘average’, with considerable individual variation (53.5 ± 11.1 %). There were no significant sex differences in the general (GNK) or sport (SNK) nutrition knowledge scores, or effect of age. Significantly higher knowledge was demonstrated by national vs. international athletes for the GNK scores (11.09 ± 1.58 vs. 9.58 ± 1.75; p = 0.028). Participants scored well in questions concerning protein, carbohydrates, alcohol, and supplements, and conversely, performed poorly in hydration and micronutrient related questions. Less than one-fifth of respondents had access to a dietitian. Forty-six percent of males and 38% of female climbers reported intentional weight loss for competition on at least one occasion. Of those, ~76% reported utilizing concerning practices, including methods that conform with disordered eating and/or eating disorders, dehydration, vomiting, and misuse of laxatives. Approximately 65% of athletes reported using at least one nutritional supplement in the previous 6 months, with 44% reporting multiple supplement use. There was no significant difference in supplement use between sexes or competition level.
Discussion
Due to the established importance of nutritional intake on athlete health and performance, educational support should be employed to improve knowledge in climbers and address shortcomings. Moreover, intentional weight loss for climbing competition is common, with most athletes achieving ~3–8% body weight loss over ≥2 weeks. It is crucial that professionals working with competitive climbers are vigilant in identifying athletes at risk of concerning weight management and establish referral pathways to the appropriate specialist services. High quality intervention trials to assess the efficacy of ergogenic aids in climbing remains inadequate.
This research delves into the implications of prolonged low-carbohydrate diets on the performance of Chinese cyclists. Low-carb diets have been a topic of increasing interest among athletes, and this study aims to shed light on their long-term effects. The investigation includes a comprehensive review of performance data, dietary adherence, and physiological responses. Findings reveal nuanced outcomes that underline the importance of personalized dietary strategies. The paper concludes with practical implications for cyclists, coaches, and prospects for further research in this domain.
Background: Diet monitoring is part of an athlete’s health and performance assessment, and adequate nutrition is known to be a method that can positively influence the reduction in exercise-induced injury. However, the concept of nutritional preparedness as a screening tool to identify low energy availability for the competitive season is not mainstream practise. Objectives: Our pilot study investigated three aims: 1) changes to nutritional status from the pre-competition phase to the competition phase, 2) living status impact on athlete’s food accessibility, and 3) whether nutritional preparedness in the pre-competition phase influenced the potential for low energy availability during the competition phase. Methods: Female volleyball athletes (N=21, 19-22 yrs., 80% lived off campus) were recruited from 3 universities (Ambrose, Calgary, New Brunswick- Saint John) through social media sites, and word of mouth. Two cross-sectional questionnaires (questions derived from the Short Food Frequency-Q, LEAF-Q, and RED-S screening tool-Q) were administered prior to and during the competitive season. Results: The nutritional assessment score significantly decreased from the pre-competition to competition phase, respectively (n=20, 26.11 ± 4.25; n=12, 20.64 ± 4.74; p=0.022). Many athletes (6/12) reported an injury during the competitive season with an average time loss from sport of 8-14 days. Conclusions: These findings suggest that collegiate female volleyball athletes have a potential for low energy availability, regardless of living status. Future research should build on the nutritional preparedness concept as a method of screening for low energy availability and the influence on injuries sustained during the competition phase.
Background:
Elite sport is continuously evolving. World records keep falling and athletes from a longer list of countries are involved.
Purpose:
This commentary was designed to provide insights into present and future trends associated with world-class endurance training based on the perspectives, experience, and knowledge of an expert panel of 25 applied sport scientists.
Results:
The key drivers of development observed in the past 10-15 years were related to (1) more accessible scientific knowledge for coaches and athletes combined with (2) better integration of practical and scientific exchange across multidisciplinary perspectives within professionalized elite athlete support structures, as well as (3) utilization of new technological advances. Based on these perspectives, we discerned and exemplified the main trends in the practice of endurance sports into the following categories: better understanding of sport-specific demands; improved competition execution; larger, more specific, and more precise training loads; improved training quality; and a more professional and healthier lifestyle. The main areas expected to drive future improvements were associated with more extensive use of advanced technology for monitoring and prescribing training and recovery, more precise use of environmental and nutritional interventions, better understanding of athlete-equipment interactions, and greater emphasis on preventing injuries and illnesses.
Conclusions:
These expert insights can serve as a platform and inspiration to develop new hypotheses and ideas, encourage future collaboration between researchers and sport practitioners, and, perhaps most important, stimulate curiosity and further collaborative studies about the training, physiology, and performance of endurance athletes.
IntroductionSports nutrition is a rapidly growing sector with increasing demand for evidence-based nutritional products to support competitive and healthy lifestyles. The product development process for novel foods should rely heavily on end-user engagement to facilitate future success, however there is a dearth of published information available. An understanding of the practices and self-reported nutritional priorities of athletes and active individuals is required for the development of new food products, facilitating evidence-based product formulation.Methods
Participants were at least 18 years of age, actively participating in competitive sport or structured physical activity on at least two occasions per week. Participants were asked to undertake a comprehensive online survey assessing their nutritional practice, perceived nutritional priorities and preferences for product characteristics. Questions were developed on the basis of critical evaluation of the current scientific literature and the hosting of two scoping focus group sessions with prospective end-users.Results405 individuals (29 ± 9 years) completed this questionnaire. 295 participants reported active participation in competitive sport while the remaining 110 participants undertook structured physical activity exclusively. When asked to rank their top three most sought-after product claims in sports nutrition, “enhanced muscular recovery” was the most prioritised receiving 101 first choice preferences (25%) and 295 top 3 preferences. Fifty-eight percent of participants reported taking nutritional supplements. Caffeine containing functional foods (excluding caffeine supplements) were the most commonly used functional food group. A very low incidence of functional food usage was reported otherwise. When asked to rank the importance of various food product attributes, “nutritional profile” was ranked as the most important with rating of 3.37 ± 0.7 out of 4 followed by “taste” and “accessibility”. Whole food nutritional products received the most first preference selections and most top 3 selections when presented with a number of popular performance and recovery products on the market.Conclusions
The transition towards a food first approach in sports nutrition is vital for athletes and active individuals to achieve their goals; with the development of evidence-based functional foods, particularly with a focus on muscle recovery, endurance, and strength enhancement at the forefront for new food product design and innovation.
Introduction:
Body composition is a fundamental indicator to define the nutritional status of the runner.
Objective:
The study aimed to evaluate the effects of the nutritional periodization intervention on the body composition of elite junior Djiboutian runners in middle distance.
Materials and methods:
The sample consisted of 22 male runners, aged between 16 and 18 years. For the assessment, an experiment consisting of 11 subjects in the control group and 11 in the experimental roup was designed. As anthropometric measurements, weight, height and six adipose tissue were taken to evaluate the percentage of fat, adiposity index, body mass index and active body substance index, since, in order to monitor the proposed intervention, an interview of reminder 24 hours seven days.
Results:
A periodized diet was designed, with the manipulation of carbohydrates. Nutritional periodization with high and low carbohydrate intake for 12 weeks significantly (p<0.05) decreased percentage fat without altering body weight or active body substance index in juvenile middle-distance Djiboutian runners from the experimental group.
Conclusions:
The exposed results contribute to improve the biomedical control of training in elite junior middle-distance runners in Djibouti, since there were data limitations on their body composition and the effect that periodized nutrition could have on these indicators.
Collegiate athletic programs are increasingly adding nutrition services to interdisciplinary sports medicine and sports performance departments in response to scientific evidence highlighting nutrition's integral role in supporting athletic performance and overall health. Registered Dietitian Nutritionists (RDNs) specializing in sports dietetics (ie, sports RDNs) and credentialed Board-certified Specialists in Sports Dietetics (CSSDs) are the preferred nutrition service providers for these programs. Their extensive training and proficiency in medical nutrition therapy, education and behavioral counseling, food-service management, exercise physiology, physical performance, and administration, as defined by the ''Standards of Practice and ''Standards of Professional Performance'' for Registered Dietitian Nutritionists in Sports Nutrition and Human Performance,'' make these practitioners uniquely qualified to deliver the breadth of care required in the collegiate setting. Therefore, this document, guided by a multidisciplinary panel, introduces four sports nutrition models through which any collegiate athletic program can deliver sports RDN-directed nutrition services. In each model, the most effective staffing and scope of service are indicated and reviewed. In addition, recommended organizational structures for sports RDN are provided that best support the delivery of the model's nutrition services in a variety of collegiate athletic programs and organizational settings. Lastly, future research initiatives and nutrition interventions to help improve the standard of care through these sport nutrition models are explored.
Os atletas possuem demandas físicas e energéticas elevadas em razão da intensa rotina de treinamento. A fim de garantir o melhor desempenho, é fundamental a ingestão adequada de nutrientes e energia, para atender as necessidades nutricionais e auxiliar na adequação da composição corporal. Neste estudo transversal, o objetivo foi caracterizar o perfil nutricional e de composição corporal de atletas de atletismo de alto rendimento. A amostra consistiu em 32 atletas de atletismo, 14 do sexo feminino e 18 do sexo masculino, sendo 13 atletas especialistas de provas de velocidade, 5 de provas de fundo (resistência), 11 de arremesso e lançamentos e 3 de saltos (em altura e distância), com idade entre 15 e 25 anos, registrados na federação da modalidade. Os atletas foram submetidos à avaliação dietética, por meio do registro alimentar e recordatório alimentar de 24 horas; avaliação do gasto energético total, por meio de um recordatório de atividades físicas diárias e avaliação antropométrica através da mensuração da massa corporal total, altura, circunferências e dobras cutâneas. Todas as aferições foram realizadas antes da prática de exercícios físicos. Os resultados obtidos demonstraram que o balanço energético encontrado foi negativo (-185,8 ± 664,0 Kcal). A ingestão energética (32,0 ± 9,1 g/kg de peso corporal; 2093,1 ± 581,5 kcal) e de carboidratos (4,2 ± 1,3 g/kg) não está próxima do recomendado por diretrizes. No entanto, a ingestão de proteínas (1,3 ± 0,7 g/kg) e lipídios (31,4 ± 8,0 g/kg) está de acordo com recomendações. Além disso, a composição corporal dos atletas está adequada, onde a média do IMC foi de 22,5 ± 3,6 kg/m2 e a média do percentual de gordura foi de 16,9 ± 8,6 %. O percentual de gordura médio dos arremessadores e lançadores, de ambos os sexos, foi estatisticamente maior do que dos velocistas (p<0,001), fundistas (p=0,05) e saltadores (p=0,008). Além disso, o Índice de Massa Corporal foi estatisticamente maior nos arremessadores e lançadores, do que dos velocistas (p<0,05) e fundistas (p<0,01). Entre os sexos, a altura (p<0,01) e a relação cintura quadril (p<0,001) foi estatisticamente maior no sexo masculino, enquanto o percentual de gordura (p<0,01) foi maior no sexo feminino. Não houve diferença significativa (p>0,05), entre os sexos e provas, para a massa corporal, circunferência do abdômen, valor calórico total, gasto energético total, balanço energético e consumo de macronutrientes. A composição corporal dos atletas de atletismo de alto rendimento está adequada, no entanto, o perfil nutricional não está totalmente de acordo com o estabelecido nas recomendações.
Os atletas possuem demandas físicas e energéticas elevadas em razão da intensa rotina de treinamento. A fim de garantir o melhor desempenho, é fundamental a ingestão adequada de nutrientes e energia, para atender as necessidades nutricionais e auxiliar na adequação da composição corporal. Neste estudo transversal, o objetivo foi caracterizar o perfil nutricional e de composição corporal de atletas de atletismo de alto rendimento. A amostra consistiu em 32 atletas de atletismo, 14 do sexo feminino e 18 do sexo masculino, sendo 13 atletas especialistas de provas de velocidade, 5 de provas de fundo (resistência), 11 de arremesso e lançamentos e 3 de saltos (em altura e distância), com idade entre 15 e 25 anos, registrados na federação da modalidade. Os atletas foram submetidos à avaliação dietética, por meio do registro alimentar e recordatório alimentar de 24 horas; avaliação do gasto energético total, por meio de um recordatório de atividades físicas diárias e avaliação antropométrica através da mensuração da massa corporal total, altura, circunferências e dobras cutâneas. Todas as aferições foram realizadas antes da prática de exercícios físicos. Os resultados obtidos demonstraram que o balanço energético encontrado foi negativo (-185,8 ± 664,0 Kcal). A ingestão energética (32,0 ± 9,1 g/kg de peso corporal; 2093,1 ± 581,5 kcal) e de carboidratos (4,2 ± 1,3 g/kg) não está próxima do recomendado por diretrizes. No entanto, a ingestão de proteínas (1,3 ± 0,7 g/kg) e lipídios (31,4 ± 8,0 g/kg) está de acordo com recomendações. Além disso, a composição corporal dos atletas está adequada, onde a média do IMC foi de 22,5 ± 3,6 kg/m2 e a média do percentual de gordura foi de 16,9 ± 8,6 %. O percentual de gordura médio dos arremessadores e lançadores, de ambos os sexos, foi estatisticamente maior do que dos velocistas (p<0,001), fundistas (p=0,05) e saltadores (p=0,008). Além disso, o Índice de Massa Corporal foi estatisticamente maior nos arremessadores e lançadores, do que dos velocistas (p<0,05) e fundistas (p<0,01). Entre os sexos, a altura (p<0,01) e a relação cintura quadril (p<0,001) foi estatisticamente maior no sexo masculino, enquanto o percentual de gordura (p<0,01) foi maior no sexo feminino. Não houve diferença significativa (p>0,05), entre os sexos e provas, para a massa corporal, circunferência do abdômen, valor calórico total, gasto energético total, balanço energético e consumo de macronutrientes. A composição corporal dos atletas de atletismo de alto rendimento está adequada, no entanto, o perfil nutricional não está totalmente de acordo com o estabelecido nas recomendações.
Purpose:
Wheelchair athletes experience a reduction in fat-free mass due to the underlying condition and/or muscle disuse. This leads to a lower resting energy expenditure (REE), as well as a lower energy expenditure during exercise or daily activities. Traditional markers of low energy availability (LEA), including amenorrhea and low bone mineral density, are often inconclusive in wheelchair athletes. This case study provides data from a professional female wheelchair badminton player with multiple sclerosis who presented with a reduced measured-to-predicted REE ratio (REEratio), a common indicator of LEA in able-bodied athletes. Furthermore, a nutrition and exercise intervention was conducted to restore REE.
Methods:
REE and body composition were measured using indirect calorimetry and dual-energy X-ray absorptiometry, respectively. The predicted REE of the REEratio was calculated using 2 separate approaches. An REEratio <0.9 was considered an indicator for LEA. A nutrition and exercise intervention was implemented to normalize REE and induce weight loss through increased meal frequency, a 200- to 400-kcal/d increase in energy intake, and added endurance exercise.
Results:
The athlete (33 y, 78 kg, 154 cm) initiallly showed an REEratio of 0.65 to 0.70, which increased to 1.00 to 1.09 after 1 year. The athlete lost 11.8 kg, almost exclusively (11 kg) in the form of fat mass. The athlete reported reduced fatigue and higher perceived fitness.
Conclusion:
The nutrition and exercise intervention successfully restored energy status, induced sustainable weight loss, and reduced fatigue in a wheelchair athlete with multiple sclerosis with presumed LEA. Methods to assess LEA in this population require further validation.
Athletes participating in the athletics (track and field) events of jumps, throws, and combined events (CEs; seven-event heptathlon and 10-event decathlon) engage in training and competition that emphasize speed and explosive movements, requiring optimal power-weight ratios. While these athletes represent a wide range of somatotypes, they share an emphasis on Type IIa and IIx muscle fiber typing. In general, athletes competing in jumps tend to have a lower body mass and may benefit from a higher protein (1.5-1.8 g PRO·kg-1·day-1) and lower carbohydrate (3-6 g CHO·kg-1·day-1) diet. Throwers tend to have a higher body mass, but with considerable differences between events. Their intense, whole-body training program suggests higher PRO requirements (1.5-2.2 g PRO·kg-1·day-1), while CHO needs (per kg) are similar to jumpers. The CE athletes must strike a balance between strength and muscle mass for throws and sprints, while maintaining a low enough body mass to maximize performance in jumps and middle-distance events. CE athletes may benefit from a higher PRO (1.5-2 g PRO·kg-1·day-1) and moderate CHO (5-8 g CHO·kg-1·day-1) diet with good energy availability to support multiple daily training sessions. Since they compete over 2 days, well-rehearsed competition-day fueling and recovery strategies are imperative for CE athletes. Depending on their events' bioenergetic demands, athletes in throws, jumps, and CE may benefit from the periodized use of ergogenic aids, including creatine, caffeine, and/or beta-alanine. The diverse training demands, physiques, and competitive environments of jumpers, throwers, and CE athletes necessitate nutrition interventions that are periodized throughout the season and tailored to the individual needs of the athlete.
The reported prevalence of low energy availability (LEA) in female and male track and field athletes is between 18% and 58% with the highest prevalence among athletes in endurance and jump events. In male athletes, LEA may result in reduced testosterone levels and libido along with impaired training capacity. In female track and field athletes, functional hypothalamic amenorrhea as consequence of LEA has been reported among 60% of elite middle- and long-distance athletes and 23% among elite sprinters. Health concerns with functional hypothalamic amenorrhea include impaired bone health, elevated risk for bone stress injury, and cardiovascular disease. Furthermore, LEA negatively affects recovery, muscle mass, neuromuscular function, and increases the risk of injuries and illness that may affect performance negatively. LEA in track and field athletes may occur due to intentional alterations in body mass or body composition, appetite changes, time constraints, or disordered eating behavior. Long-term LEA causes metabolic and physiological adaptations to prevent further weight loss, and athletes may therefore be weight stable yet have impaired physiological function secondary to LEA. Achieving or maintaining a lower body mass or fat levels through long-term LEA may therefore result in impaired health and performance as proposed in the Relative Energy Deficiency in Sport model. Preventive educational programs and screening to identify athletes with LEA are important for early intervention to prevent long-term secondary health consequences. Treatment for athletes is primarily to increase energy availability and often requires a team approach including a sport physician, sports dietitian, physiologist, and psychologist.
Middle-distance runners utilize the full continuum of energy systems throughout training, and given the infinite competition tactical scenarios, this event group is highly complex from a performance intervention point of view. However, this complexity results in numerous potential periodized nutrition interventions to optimize middle-distance training adaptation and competition performance. Middle-distance race intensity is extreme, with 800m to 5,000m races being at ~95 to 130% of VO2max. Accordingly, elite middle-distance runners have primarily Type IIa / IIx fiber morphology and rely almost exclusively on carbohydrate (primarily muscle glycogen) metabolic pathways for producing ATP. Consequently, the principle nutritional interventions that should be emphasized are those that optimize muscle glycogen contents to support high glycolytic flux (resulting in very high lactate values, of >20mmol/L in some athletes) with appropriate buffering capabilities, while optimizing power to weight ratios, all in a macro and micro-periodized manner. From youth to elite level, middle-distance athletes have arduous racing schedules (10-25 races/year), coupled with excessive global travel, which can take a physical and emotional toll. Accordingly, proactive and integrated nutrition planning can have a profound recovery effect over a long race season, as well as optimizing recovery during rounds of championship racing. Finally, with evidence-based implementation, and an appropriate risk/reward assessment, several ergogenic aids may have an adaptive and/or performance-enhancing effect in the middle-distance athlete. Given that elite middle-distance athletes undertake ~400 to 800 training sessions with 10 to 25 races/year, there are countless opportunities to implement various periodized acute and chronic nutrition-based interventions to optimize performance.
Background:
Skeletal muscle glycogen is an important energy source for muscle contraction and a key regulator of metabolic responses to exercise. Manipulation of muscle glycogen is therefore a strategy to improve performance in competitions and potentially adaptation to training. However, assessing muscle glycogen in the field is impractical, and there are no normative values for glycogen concentration at rest and during exercise.
Objective:
The objective of this study was to meta-analyse the effects of fitness, acute dietary carbohydrate (CHO) availability and other factors on muscle glycogen concentration at rest and during exercise of different durations and intensities.
Data source and study selection:
PubMed was used to search for original articles in English published up until February 2018. Search terms included muscle glycogen and exercise, filtered for humans. The analysis incorporated 181 studies of continuous or intermittent cycling and running by healthy participants, with muscle glycogen at rest and during exercise determined by biochemical analysis of biopsies.
Data analysis:
Resting muscle glycogen was determined with a meta-regression mixed model that included fixed effects for fitness status [linear, as maximal oxygen uptake ([Formula: see text]O2max) in mL·kg-1·min-1] and CHO availability (three levels: high, ≥ 6 g·kg-1 of CHO per day for ≥ 3 days or ≥ 7 g·kg-1 CHO per day for ≥ 2 days; low, glycogen depletion and low-CHO diet; and normal, neither high nor low, or not specified in study). Muscle glycogen during exercise was determined with a meta-regression mixed model that included fixed effects for fitness status, resting glycogen [linear, in mmol·kg-1 of dry mass (DM)], exercise duration (five levels, with means of 5, 23, 53 and 116 min, and time to fatigue), and exercise intensity (linear, as percentage of [Formula: see text]O2max); intensity, fitness and resting glycogen were interacted with duration, and there were also fixed effects for exercise modes, CHO ingestion, sex and muscle type. Random effects in both models accounted for between-study variance and within-study repeated measurement. Inferences about differences and changes in glycogen were based on acceptable uncertainty in standardised magnitudes, with thresholds for small, moderate, large and very large of 25, 75, 150 and 250 mmol·kg-1 of DM, respectively.
Results:
The resting glycogen concentration in the vastus lateralis of males with normal CHO availability and [Formula: see text]O2max (mean ± standard deviation, 53 ± 8 mL·kg-1·min-1) was 462 ± 132 mmol·kg-1. High CHO availability was associated with a moderate increase in resting glycogen (102, ± 47 mmol·kg-1; mean ± 90% confidence limits), whereas low availability was associated with a very large decrease (- 253, ± 30 mmol·kg-1). An increase in [Formula: see text]O2max of 10 mL·kg-1·min-1 had small effects with low and normal CHO availability (29, ± 44 and 67, ± 15 mmol·kg-1, respectively) and a moderate effect with high CHO availability (80, ± 40 mmol·kg-1). There were small clear increases in females and the gastrocnemius muscle. Clear modifying effects on glycogen utilisation during exercise were as follows: a 30% [Formula: see text]O2max increase in intensity, small (41, ± 20 mmol·kg-1) at 5 min and moderate (87-134 mmol·kg-1) at all other timepoints; an increase in baseline glycogen of 200 mmol·kg-1, small at 5-23 min (28-59 mmol·kg-1), moderate at 116 min (104, ± 15 mmol·kg-1) and moderate at fatigue (143, ± 33 mmol·kg-1); an increase in [Formula: see text]O2max of 10 mL·kg-1·min-1, mainly clear trivial effects; exercise mode (intermittent vs. continuous) and CHO ingestion, clear trivial effects. Small decreases in utilisation were observed in females (vs. males: - 30, ± 29 mmol·kg-1), gastrocnemius muscle (vs. vastus lateralis: - 31, ± 46 mmol·kg-1) and running (vs. cycling: - 70, ± 32 mmol·kg-1).
Conclusion:
Dietary CHO availability and fitness are important factors for resting muscle glycogen. Exercise intensity and baseline muscle glycogen are important factors determining glycogen use during exercise, especially with longer exercise duration. The meta-analysed effects may be useful normative values for prescription of endurance exercise.
Since the introduction of the muscle biopsy technique in the late 1960s, our understanding of the regulation of muscle glycogen storage and metabolism has advanced considerably. Muscle glycogenolysis and rates of carbohydrate (CHO) oxidation are affected by factors such as exercise intensity, duration, training status and substrate availability. Such changes to the global exercise stimulus exert regulatory effects on key enzymes and transport proteins via both hormonal control and local allosteric regulation. Given the well-documented effects of high CHO availability on promoting exercise performance, elite endurance athletes are typically advised to ensure high CHO availability before, during and after high-intensity training sessions or competition. Nonetheless, in recognition that the glycogen granule is more than a simple fuel store, it is now also accepted that glycogen is a potent regulator of the molecular cell signaling pathways that regulate the oxidative phenotype. Accordingly, the concept of deliberately training with low CHO availability has now gained increased popularity amongst athletic circles. In this review, we present an overview of the regulatory control of CHO metabolism during exercise (with a specific emphasis on muscle glycogen utilization) in order to discuss the effects of both high and low CHO availability on modulating exercise performance and training adaptations, respectively.
Deliberately training with reduced carbohydrate (CHO) availability to enhance endurance-training-induced metabolic adaptations of skeletal muscle (i.e. the ‘train low, compete high’ paradigm) is a hot topic within sport nutrition. Train-low studies involve periodically training (e.g., 30–50% of training sessions) with reduced CHO availability, where train-low models include twice per day training, fasted training, post-exercise CHO restriction and ‘sleep low, train low’. When compared with high CHO availability, data suggest that augmented cell signalling (73% of 11 studies), gene expression (75% of 12 studies) and training-induced increases in oxidative enzyme activity/protein content (78% of 9 studies) associated with ‘train low’ are especially apparent when training sessions are commenced within a specific range of muscle glycogen concentrations. Nonetheless, such muscle adaptations do not always translate to improved exercise performance (e.g. 37 and 63% of 11 studies show improvements or no change, respectively). Herein, we present our rationale for the glycogen threshold hypothesis, a window of muscle glycogen concentrations that simultaneously permits completion of required training workloads and activation of the molecular machinery regulating training adaptations. We also present the ‘fuel for the work required’ paradigm (representative of an amalgamation of train-low models) whereby CHO availability is adjusted in accordance with the demands of the upcoming training session(s). In order to strategically implement train-low sessions, our challenge now is to quantify the glycogen cost of habitual training sessions (so as to inform the attainment of any potential threshold) and ensure absolute training intensity is not compromised, while also creating a metabolic milieu conducive to facilitating the endurance phenotype.
Endurance athletes are at increased risk of relative energy deficiency associated with metabolic perturbation and impaired health. We aimed to estimate and compare within-day energy balance (WDEB) in male athletes with suppressed and normal resting metabolic rate (RMR) and explore if within-day energy deficiency (WDED) is associated with endocrine markers of energy deficiency. Thirty-one male cyclists, triathletes, and long-distance runners recruited from regional competitive sports clubs were included. The protocol comprised measurements of RMR by ventilated hood, and energy intake and energy expenditure to predict RMRratio (measured RMR/predicted RMR), energy availability (EA), 24-hour energy balance (EB) and WDEB in 1-hour intervals, assessment of body-composition by dual-energy X-ray absorptiometry, and blood plasma analysis. Subjects were categorized as having suppressed (RMRratio < 0.90, n=20) or normal RMR (RMRratio > 0.90, n=11). Despite no observed differences in 24-hour EB or EA between the groups, subjects with suppressed RMR spent more time in an energy deficit exceeding 400 kcal (20.9 [18.8 - 21.8] hours vs. 10.8 [2.5 - 16.4], P=0.023), and had larger single-hour energy deficits compared to subjects with normal RMR (3265 ± 1963 kcal vs. -1340 ± 2439, P=0.023). Larger single-hour energy deficits were associated with higher cortisol levels (r = -0.499, P=0.004) and a lower testosterone:cortisol ratio (r = 0.431, P=0.015), but no associations with T3 or fasting blood glucose were observed. In conclusion, WDED was associated with suppressed RMR and catabolic markers in male endurance athletes.
We aimed to (1) report energy availability (EA), metabolic/reproductive function, bone mineral density (BMD) and injury/illness rates in national/world-class female and male distance-athletes; and (2) investigate the robustness of various diagnostic criteria from the Female Athlete Triad (Triad), Low Energy Availability in Females Questionnaire (LEAF-Q) and Relative Energy Deficiency in Sport (RED-S) tools to identify risks associated with low EA. Athletes were distinguished according to benchmarks of reproductive function (amenorrheic [n=13] vs eumenorrheic [n=22]; low [lowest quartile of reference range, n=10] vs normal testosterone [n=14]) and EA calculated from 7-day food and training diaries (< or >30 kcal.kg-1FFM). Sex hormones (p<0.001), triiodothyronine (p<0.05) and BMD (females, p<0.05) were significantly lower in amenorrheic (37%) and low testosterone (40%; 15.1±3.0 nmol/L-1) athletes and bone injuries were ~4.5-fold more prevalent in amenorrheic (ES=0.85; large) and low testosterone (ES=0.52; moderate) groups compared to others. Categorization of females and males using Triad or RED-S tools revealed that higher risk groups had significantly lower T3 (female and male Triad and RED-S:p<0.05) and higher number of all-time fractures (male Triad:p<0.001; male RED-S and female Triad:p<0.01) as well as non-significant but markedly (up to 10-fold) higher number of training days lost to bone injuries during the preceding year. Based on the cross-sectional analysis, current reproductive function (questionnaires/blood hormone concentrations) appears to provide a more objective and accurate marker of optimal energy for health than the more error-prone and time-consuming dietary and training estimation of EA. This study also offers novel findings that athlete health is associated with EA indices.
Periodization theory has, over the past seven
decades, emerged as the preeminent training planning
paradigm. The philosophical underpinnings of periodiza-
tion theory can be traced back to the integration of diverse
shaping influences, whereby coaching beliefs and traditions
were blended with historically available scientific insights
and contextualized against pervading social planning
models. Since then, many dimensions of elite preparation
have evolved significantly, as driven by a combination of
coaching innovations and science-led advances in training
theory, techniques, and technologies. These advances have
been incorporated into the fabric of the pre-existing peri-
odization planning framework, yet the philosophical
assumptions underpinning periodization remain largely
unchallenged and unchanged. One particularly influential
academic sphere of study, the science of stress, particularly
the work of Hans Selye, is repeatedly cited by theorists as a
central pillar upon which periodization theory is founded.
A fundamental assumption emanating from the early stress
research is that physical stress is primarily a biologically
mediated phenomenon: a presumption translated to athletic
performance contexts as evidence that mechanical training
stress directly regulates the magnitude of subsequent ‘fit-
ness’ adaptations. Interestingly, however, since periodiza-
tion theory first emerged, the science of stress has evolved
extensively from its historical roots. This raises a funda-
mental question: if the original scientific platform upon
which periodization theory was founded has disintegrated,
should we critically re-evaluate conventional perspectives
through an updated conceptual lens? Realigning peri-
odization philosophy with contemporary stress theory thus
presents us with an opportunity to recalibrate training
planning models with both contemporary scientific insight
and progressive coaching practice.
It is becoming increasingly clear that adaptations, initiated by exercise, can be amplified or reduced by nutrition. Various methods have been discussed to optimize training adaptations and some of these methods have been subject to extensive study. To date, most methods have focused on skeletal muscle, but it is important to note that training effects also include adaptations in other tissues (e.g., brain, vasculature), improvements in the absorptive capacity of the intestine, increases in tolerance to dehydration, and other effects that have received less attention in the literature. The purpose of this review is to define the concept of periodized nutrition (also referred to as nutritional training) and summarize the wide variety of methods available to athletes. The reader is referred to several other recent review articles that have discussed aspects of periodized nutrition in much more detail with primarily a focus on adaptations in the muscle. The purpose of this review is not to discuss the literature in great detail but to clearly define the concept and to give a complete overview of the methods available, with an emphasis on adaptations that are not in the muscle. Whilst there is good evidence for some methods, other proposed methods are mere theories that remain to be tested. ‘Periodized nutrition’ refers to the strategic combined use of exercise training and nutrition, or nutrition only, with the overall aim to obtain adaptations that support exercise performance. The term nutritional training is sometimes used to describe the same methods and these terms can be used interchangeably. In this review, an overview is given of some of the most common methods of periodized nutrition including ‘training low’ and ‘training high’, and training with low- and high-carbohydrate availability, respectively. ‘Training low’ in particular has received considerable attention and several variations of ‘train low’ have been proposed. ‘Training-low’ studies have generally shown beneficial effects in terms of signaling and transcription, but to date, few studies have been able to show any effects on performance. In addition to ‘train low’ and ‘train high’, methods have been developed to ‘train the gut’, train hypohydrated (to reduce the negative effects of dehydration), and train with various supplements that may increase the training adaptations longer term. Which of these methods should be used depends on the specific goals of the individual and there is no method (or diet) that will address all needs of an individual in all situations. Therefore, appropriate practical application lies in the optimal combination of different nutritional training methods. Some of these methods have already found their way into training practices of athletes, even though evidence for their efficacy is sometimes scarce at best. Many pragmatic questions remain unanswered and another goal of this review is to identify some of the remaining questions that may have great practical relevance and should be the focus of future research.
The gastrointestinal (GI) tract plays a critical role in delivering carbohydrate and fluid during prolonged exercise and can therefore be a major determinant of performance. The incidence of GI problems in athletes participating in endurance events is high, indicating that GI function is not always optimal in those conditions. A substantial body of evidence suggests that the GI system is highly adaptable. Gastric emptying as well as stomach comfort can be “trained” and perceptions of fullness decreased; some studies have suggested that nutrient-specific increases in gastric emptying may occur. Evidence also shows that diet has an impact on the capacity of the intestine to absorb nutrients. Again, the adaptations that occur appear to be nutrient specific. For example, a high-carbohydrate diet will increase the density of sodium-dependent glucose-1 (SGLT1) transporters in the intestine as well as the activity of the transporter, allowing greater carbohydrate absorption and oxidation during exercise. It is also likely that, when such adaptations occur, the chances of developing GI distress are smaller. Future studies should include more human studies and focus on a number of areas, including the most effective methods to induce gut adaptations and the timeline of adaptations. To develop effective strategies, a better understanding of the exact mechanisms underlying these adaptations is important. It is clear that “nutritional training” can improve gastric emptying and absorption and likely reduce the chances and/or severity of GI problems, thereby improving endurance performance as well as providing a better experience for the athlete. The gut is an important organ for endurance athletes and should be trained for the conditions in which it will be required to function.
Background
Endurance athletes perform periodized training in order to prepare for main competitions and maximize performance. However, the coupling between alterations of total energy expenditure (TEE), energy intake, and body composition during different seasonal training phases is unclear. So far, no systematic review has assessed fluctuations in TEE, energy intake, and/or body composition in endurance athletes across the training season.The purpose of this study was to (1) systematically analyze TEE, energy intake, and body composition in highly trained athletes of various endurance disciplines and of both sexes and (2) analyze fluctuations in these parameters across the training season. Methods
An electronic database search was conducted on the SPORTDiscus and MEDLINE (January 1990–31 January 2015) databases using a combination of relevant keywords.Two independent reviewers identified potentially relevant studies. Where a consensus was not reached, a third reviewer was consulted. Original research articles that examined TEE, energy intake, and/or body composition in 18–40-year-old endurance athletes and reported the seasonal training phases of data assessment were included in the review. Articles were excluded if body composition was assessed by skinfold measurements, TEE was assessed by questionnaires, or data could not be split between the sexes.Two reviewers assessed the quality of studies independently. Data on subject characteristics, TEE, energy intake, and/or body composition were extracted from the included studies. Subjects were categorized according to their sex and endurance discipline and each study allocated a weight within categories based on the number of subjects assessed. Extracted data were used to calculate weighted means and standard deviations for parameters of TEE, energy intake, and/or body composition. ResultsFrom 3589 citations, 321 articles were identified as potentially relevant, with 82 meeting all of the inclusion criteria. TEE of endurance athletes was significantly higher during the competition phase than during the preparation phase (p < 0.001) and significantly higher than energy intake in both phases (p < 0.001). During the competition phase, both body mass and fat-free mass were significantly higher compared to other seasonal training phases (p < 0.05). Conclusions
Limitations of the present study included insufficient data being available for all seasonal training phases and thus low explanatory power of single parameters. Additionally, the classification of the different seasonal training phases has to be discussed.Male and female endurance athletes show important training seasonal fluctuations in TEE, energy intake, and body composition. Therefore, dietary intake recommendations should take into consideration other factors including the actual training load, TEE, and body composition goals of the athlete.
Due to gastrointestinal tract adaptability, the study aimed to determine the impact of gut-training protocol over 2 weeks on gastrointestinal status, blood glucose availability, fuel kinetics, and running performance. Endurance runners (n = 25) performed a gut-challenge trial (GC1), consisting of 2 h running exercise at 60% V̇O2max whilst consuming gel-discs containing 30 g carbohydrates (2:1 glucose/fructose, 10% w/v) every 20 min and a 1 h distance test. Participants were then randomly assigned to a carbohydrate gel-disc (CHO-S), carbohydrate food (CHO-F), or placebo (PLA) gut-training group for 2 weeks of repetitive gut-challenge intervention. Participants then repeated a second gut-challenge trial (GC2). Gastrointestinal symptoms reduced in GC2 on CHO-S (60%; p = 0.008) and CHO-F (63%; p = 0.046); reductions were greater than PLA (p < 0.05). H2 peak was lower in GC2 on CHO-S (mean (CI): 6 (4–8) ppm) compared with CHO-F (9 (6–12) ppm) and PLA (12 (2–21) ppm) (trial × time: p < 0.001). Blood glucose concentration was higher in GC2 on CHO-S (7.2 (6.3–8.1) mmol·L⁻¹) compared with CHO-F (6.1 (5.7–6.5) mmol·L⁻¹) and PLA (6.2 (4.9–7.5) mmol·L⁻¹) (trial × time: p = 0.015). No difference in oxidation rates, plasma I-FABP, and cortisol concentrations were observed between groups and trials. Distance test improved on CHO-S (5.2%) and CHO-F (4.3%) in GC2, but not on PLA (–2.1%) (trial × time: p = 0.009). Two weeks of gut-training with CHO-S and CHO-F improved gastrointestinal symptoms and running performance compared with PLA. CHO-S also reduced malabsorption and increased blood glucose availability during endurance running compared with PLA.
Accurate estimation of energy expenditure is a key element in determining the relationships between aspects of human behavior , physical activity, and overall health. 1,2 Although wear-able devices for estimating energy expenditure are becoming increasingly popular, there is little evidence regarding their validity. 3,4 This study was performed to examine the validity of total energy expenditure estimates made by several wearable devices compared with gold standard measurements for a standardized day (metabolic chamber method) and free-living days (doubly labeled water [DLW] method).
Purpose:
We investigated the effect of a chronic dietary periodization strategy on endurance performance in trained athletes.
Methods:
21 triathletes (V[Combining Dot Above]O2max: 58.7 ± 5.7 mL·min·kg) were divided into 2 groups: a "sleep-low" (SL, n = 11) and a control group (CON, n = 10) consumed the same daily carbohydrate (CHO) intake (6 g·kg·d) but with different timing over the day to manipulate CHO availability before and after training sessions. The "sleep low" strategy consisted of a 3-week training/diet intervention comprising three blocks of diet/exercise manipulations: 1) "train-high" interval training sessions (HIT) in the evening with high-CHO availability; 2) overnight CHO restriction ("sleeping-low"), and 3) "train-low" sessions with low endogenous and exogenous CHO availability. The CON group followed the same training program but with high CHO availability throughout training sessions (no CHO restriction overnight, training sessions with exogenous CHO provision).
Results:
There was a significant improvement in delta efficiency during submaximal cycling for SL versus CON (CON: +1.4 ± 9.3 %, SL: +11 ± 15 %, P<0.05). SL also improved supra-maximal cycling to exhaustion at 150% of peak aerobic power (CON: +1.63 ± 12.4 %, SL: +12.5 ± 19.0 %; P = 0.06) and 10 km running performance (CON: -0.10 ± 2.03 %, SL: -2.9 ± 2.15 %; P < 0.05). Fat mass was decreased in SL (CON: -2.6 ± 7.4; SL: -8.5 ± 7.4 %PRE, P < 0.01), but not lean mass (CON: -0.22 ± 1.0; SL: -0.16 ± 1.7 %PRE).
Conclusion:
Short-term periodization of dietary CHO availability around selected training sessions promoted significant improvements in submaximal cycling economy, as well as supra-maximal cycling capacity and 10 km running time in trained endurance athletes.
A major goal of training to improve the performance of prolonged, continuous, endurance events lasting up to 3 h is to promote a range of physiological and metabolic adaptations that permit an athlete to work at both higher absolute and relative power outputs/speeds and delay the onset of fatigue (i.e., a decline in exercise intensity). To meet these goals, competitive endurance athletes undertake a prodigious volume of training, with a large proportion performed at intensities that are close to or faster than race pace and highly dependent on carbohydrate (CHO)-based fuels to sustain rates of muscle energy production [i.e., match rates of adenosine triphosphate (ATP) hydrolysis with rates of resynthesis]. Consequently, to sustain muscle energy reserves and meet the daily demands of training sessions, competitive athletes freely select CHO-rich diets. Despite renewed interest in high-fat, low-CHO diets for endurance sport, fat-rich diets do not improve training capacity or performance, but directly impair rates of muscle glycogenolysis and energy flux, limiting high-intensity ATP production. When highly trained athletes compete in endurance events lasting up to 3 h, CHO-, not fat-based fuels are the predominant fuel for the working muscles and CHO, not fat, availability becomes rate limiting for performance.
During the period 1985-2005, studies examined the proposal that adaptation to a low-carbohydrate (<25 % energy), high-fat (>60 % energy) diet (LCHF) to increase muscle fat utilization during exercise could enhance performance in trained individuals by reducing reliance on muscle glycogen. As little as 5 days of training with LCHF retools the muscle to enhance fat-burning capacity with robust changes that persist despite acute strategies to restore carbohydrate availability (e.g., glycogen supercompensation, carbohydrate intake during exercise). Furthermore, a 2- to 3-week exposure to minimal carbohydrate (<20 g/day) intake achieves adaptation to high blood ketone concentrations. However, the failure to detect clear performance benefits during endurance/ultra-endurance protocols, combined with evidence of impaired performance of high-intensity exercise via a down-regulation of carbohydrate metabolism led this author to dismiss the use of such fat-adaptation strategies by competitive athletes in conventional sports. Recent re-emergence of interest in LCHF diets, coupled with anecdotes of improved performance by sportspeople who follow them, has created a need to re-examine the potential benefits of this eating style. Unfortunately, the absence of new data prevents a different conclusion from being made. Notwithstanding the outcomes of future research, there is a need for better recognition of current sports nutrition guidelines that promote an individualized and periodized approach to fuel availability during training, allowing the athlete to prepare for competition performance with metabolic flexibility and optimal utilization of all muscle substrates. Nevertheless, there may be a few scenarios where LCHF diets are of benefit, or at least are not detrimental, for sports performance.
Bone resorption is increased following running, with no change in bone formation. Feeding during exercise might attenuate this increase, preventing associated problems for bone. To investigate the immediate and short-term bone metabolic responses to carbohydrate (CHO) feeding during treadmill running.
Ten men completed two 7 d trials, once being fed CHO (8% glucose immediately before, every 20 min during and immediately after exercise at a rate of 0.7 gCHO·kg(-1)BM·h(-1)) and once placebo (PBO). On day 4 of each trial, participants completed a 120 min treadmill run at 70% VO2max. Blood was taken at baseline (BASE) immediately after exercise (EE), after 60 (R1) and 120 (R2) min of recovery and on 3 follow-up days (FU1-FU3). Markers of bone resorption (β-CTX) and formation (P1NP) were measured, along with OC, PTH, ACa, PO4, GLP-2, IL-6, insulin, cortisol, leptin and OPG. Area under the curve was calculated in terms of the immediate (BASE, EE, R1 and R2) and short-term (BASE, FU1, FU2 and FU3) responses to exercise.
β-CTX, P1NP and IL-6 responses to exercise were significantly lower in the immediate post-exercise period with CHO feeding (β-CTX: P=0.028; P1NP: P=0.021; IL-6: P=0.036), although there was no difference in the short-term response (β-CTX: P=0.856; P1NP: P=0.721; IL-6: P=0.327). No other variable was significantly affected by CHO feeding during exercise.
CHO feeding during exercise attenuated the β-CTX and P1NP responses in the hours but not days following exercise, indicating an acute effect of CHO feeding on bone turnover.
Copyright © 2015, Journal of Applied Physiology.
Abstract A key element contributing to deteriorating exercise capacity during physically demanding sport appears to be reduced carbohydrate availability coupled with an inability to effectively utilize alternative lipid fuel sources. Paradoxically, cognitive and physical decline associated with glycogen depletion occurs in the presence of an over-abundance of fuel stored as body fat that the athlete is apparently unable to access effectively. Current fuelling tactics that emphasize high-carbohydrate intakes before and during exercise inhibit fat utilization. The most efficient approach to accelerate the body's ability to oxidize fat is to lower dietary carbohydrate intake to a level that results in nutritional ketosis (i.e., circulating ketone levels >0.5 mmol/L) while increasing fat intake for a period of several weeks. The coordinated set of metabolic adaptations that ensures proper interorgan fuel supply in the face of low-carbohydrate availability is referred to as keto-adaptation. Beyond simply providing a stable source of fuel for the brain, the major circulating ketone body, beta-hydroxybutyrate, has recently been shown to act as a signalling molecule capable of altering gene expression, eliciting complementary effects of keto-adaptation that could extend human physical and mental performance beyond current expectation. In this paper, we review these new findings and propose that the shift to fatty acids and ketones as primary fuels when dietary carbohydrate is restricted could be of benefit for some athletes.
Performing exercise in a glycogen depleted state increases skeletal muscle lipid utilization and the transcription of genes regulating mitochondrial β-oxidation. Potential candidates for glycogen-mediated metabolic adaptation are the peroxisome proliferator activated receptor (PPAR) coactivator-1α (PGC-1α) and the transcription factor/nuclear receptor PPAR-∂. It was therefore the aim of the present study to examine whether acute exercise with or without glycogen manipulation affects PGC-1α and PPAR-∂ function in rodent skeletal muscle. Twenty female Wistar rats were randomly assigned to 5 experimental groups (n = 4): control [CON]; normal glycogen control [NG-C]; normal glycogen exercise [NG-E]; low glycogen control [LG-C]; and low glycogen exercise [LG-E]). Gastrocnemius (GTN) muscles were collected immediately following exercise and analyzed for glycogen content, PPAR-∂ activity via chromatin immunoprecipitation (ChIP) assays, AMPK α1/α2 kinase activity, and the localization of AMPK and PGC-1α. Exercise reduced muscle glycogen by 47 and 75% relative to CON in the NG-E and LG-E groups, respectively. Exercise that started with low glycogen (LG-E) finished with higher AMPK-α2 activity (147%, p<0.05), nuclear AMPK-α2 and PGC-1α, but no difference in AMPK-α1 activity compared to CON. In addition, PPAR-∂ binding to the CPT1 promoter was significantly increased only in the LG-E group. Finally, cell reporter studies in contracting C2C12 myotubes indicated that PPAR-∂ activity following contraction is sensitive to glucose availability, providing mechanistic insight into the association between PPAR-∂ and glycogen content/substrate availability. The present study is the first to examine PPAR-∂ activity in skeletal muscle in response to an acute bout of endurance exercise. Our data would suggest that a factor associated with muscle contraction and/or glycogen depletion activates PPAR-∂ and initiates AMPK translocation in skeletal muscle in response to exercise.
The mechanisms that regulate the enhanced skeletal muscle oxidative capacity observed when training with reduced carbohydrate (CHO) availability are currently unknown. The aim of the present study was to test the hypothesis that reduced CHO availability enhances p53 signalling and expression of genes associated with regulation of mitochondrial biogenesis and substrate utilisation in human skeletal muscle. In a repeated measures design, muscle biopsies (vastus lateralis) were obtained from eight active males before and after performing an acute bout of high-intensity interval running with either high (HIGH) or low CHO availability (LOW). Resting muscle glycogen (HIGH, 467 ± 19; LOW, 103 ± 9 mmol.kg(-1) dw) was greater in HIGH compared with LOW (P<0.05). Phosphorylation (P-) of ACC(Ser79) (HIGH, 1.4 ± 0.4; LOW, 2.9 ± 0.9) and p53(Ser15) (HIGH, 0.9 ± 0.4; LOW, 2.6 ± 0.8) was higher in LOW immediately post- and 3 h post-exercise, respectively (P<0.05). Before and 3 h post-exercise, mRNA content of PDK4, Tfam, COXIV and PGC-1α were greater in LOW compared with HIGH (P<0.05) whereas CPT1 showed trend towards significance (P=0.09). However, only PGC-1α expression was increased by exercise (P<0.05) where 3-fold increases occurred independent of CHO availability. We conclude that the exercise-induced increase in p53 phosphorylation is enhanced in conditions of reduced CHO availability which may be related to upstream signalling through AMPK. Given the emergence of p53 as a molecular regulator of mitochondrial biogenesis, such nutritional modulation of contraction-induced p53 activation has implications for both athletic and clinical populations.
Effective coaching is a mixture of pedagogy and principles of sciences, e.g., motor skill acquisition, sociology, and physiology, often referred to as the science of coaching. Instinctive or intuitive coaching has often been incorrectly viewed as the art of coaching. More important should be how coaches develop knowledge, how they access that knowledge at the appropriate times and how this affects their decision-making process. The study of expert coaches should allow inferences to be drawn from their development and applied to coach education. This article intends to clarify coaching expertise and examine the role of tacit knowledge within coaching. The lack of a clear development pathway for aspiring expert coaches is a clear indicator that the current coach education system needs review. Any effective education system should be based on knowledge and understanding rather than mimicry and the implications for the future of coach education are considered. (Contains 2 figures.)
Recent studies suggest that carbohydrate restriction can improve the training-induced adaptation of muscle oxidative capacity. However, the importance of low muscle glycogen on the molecular signaling of mitochondrial biogenesis remains unclear. Here, we compare the effects of exercise with low (LG) and normal (NG) glycogen on different molecular factors involved in the regulation of mitochondrial biogenesis. Ten highly trained cyclists (VO2max 65 ± 1 ml/kg/min, W
max 387 ± 8 W) exercised for 60 min at approximately 64 % VO2max with either low [166 ± 21 mmol/kg dry weight (dw)] or normal (478 ± 33 mmol/kg dw) muscle glycogen levels achieved by prior exercise/diet intervention. Muscle biopsies were taken before, and 3 h after, exercise. The mRNA of peroxisome proliferator-activated receptor-γ coactivator-1 was enhanced to a greater extent when exercise was performed with low compared with normal glycogen levels (8.1-fold vs. 2.5-fold increase). Cytochrome c oxidase subunit I and pyruvate dehydrogenase kinase isozyme 4 mRNA were increased after LG (1.3- and 114-fold increase, respectively), but not after NG. Phosphorylation of AMP-activated protein kinase, p38 mitogen-activated protein kinases and acetyl-CoA carboxylase was not changed 3 h post-exercise. Mitochondrial reactive oxygen species production and glutathione oxidative status tended to be reduced 3 h post-exercise. We conclude that exercise with low glycogen levels amplifies the expression of the major genetic marker for mitochondrial biogenesis in highly trained cyclists. The results suggest that low glycogen exercise may be beneficial for improving muscle oxidative capacity.
The planning and organization of athletic training have historically been much discussed and debated in the coaching and sports science literature. Various influential periodization theorists have devised, promoted, and substantiated particular training-planning models based on interpretation of the scientific evidence and individual beliefs and experiences. Superficially, these proposed planning models appear to differ substantially. However, at a deeper level, it can be suggested that such models share a deep-rooted cultural heritage underpinned by a common set of historically pervasive planning beliefs and assumptions. A concern with certain of these formative assumptions is that, although no longer scientifically justifiable, their shaping influence remains deeply embedded. In recent years substantial evidence has emerged demonstrating that training responses vary extensively, depending upon multiple underlying factors. Such findings challenge the appropriateness of applying generic methodologies, founded in overly simplistic rule-based decision making, to the planning problems posed by inherently complex biological systems. The purpose of this review is not to suggest a whole-scale rejection of periodization theories but to promote a refined awareness of their various strengths and weaknesses. Eminent periodization theorists-and their variously proposed periodization models-have contributed substantially to the evolution of training-planning practice. However, there is a logical line of reasoning suggesting an urgent need for periodization theories to be realigned with contemporary elite practice and modern scientific conceptual models. In concluding, it is recommended that increased emphasis be placed on the design and implementation of sensitive and responsive training systems that facilitate the guided emergence of customized context-specific training-planning solutions.