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Steps at which gene expression can be controlled/regulated. The effect of diet/training interactions on these processes is largely unknown. Adapted and redrawn from Williams and Neufer (1996).
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Training and nutrition are highly interrelated in that optimal adaptation to the demands of repeated training sessions typically requires a diet that can sustain muscle energy reserves. As nutrient stores (i.e. muscle and liver glycogen) play a predominant role in the performance of prolonged, intense, intermittent exercise typical of the patterns...
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... alone (Nelson, Arnall, Loy, Silverster, & Conlee, 1990). With regard to the effects of contraction on gene expression, many studies have reported that mRNA abundance for several metabolic and stress-related genes is acutely and transiently elevated in muscle after a single bout of exercise (Cluberton, McGee, Murphy, & Hargreaves, 2005; Kraniou, Cameron- Smith, Misso, Collier, & Hargreaves, 2000; Neufer & Dohm, 1993; Pilegaard et al ., 2000). Indeed, it appears that for many exercise-related genes, the time-course of transcriptional activation occurs during the first few hours of recovery (Pilegaard et al ., 2000), and may be linked by common signalling and/or regulatory mechanisms to the restoration of muscle energy stores, predominantly glycogen (Richter, Derave, & Wojtaszewski, 2001). As gene expression and its associated phenotypic/ functional manifestations do not occur until there is an increase in the concentration of the protein encoded by the gene, the extent to which a protein will increase in response to an adaptive stimulus cannot be predicted from the increase in mRNA. This makes the measurement of protein concentrations critical when studying the adaptive responses to exercise training or other stimuli (Baar et al ., 2002). Physical preparation for soccer requires several divergent yet interdependent types of training incorporating sprint, endurance, and resistance training (Bangsbo, 1994). Under conditions in which the training inputs (intensity, duration, and frequency) are held constant, any training programme must be of sufficient length for the cellular proteins to reach their new ‘‘steady-state’’ concentration and the biochemical/metabolic adaptations to develop fully (Hildebrandt et al ., 2003; Terjung & Hood, 1986). Changes in dietary intake that alter the concentration of blood-borne nutrients and hormones can regulate the short-term macronutrient oxidative and storage profile of skeletal muscle. Perturbations in muscle and blood substrates (especially carbohydrate and fat) alter the uptake and flux of these fuel-specific intermediates within related metabolic pathways (i.e. skeletal muscle). This response serves to redirect enzymatic processes involved in substrate metabolism and the subsequent concentration of particular proteins critical for metabolic pathway function. Altering substrate availability affects not only resting energy metabolism and subsequent fuel utilization during exercise, but also regulatory processes underlying gene expression (Arkinstall, Tunstall, Cameron- Smith, & Hawley, 2004; Hargreaves & Cameron- Smith, 2002; Tunstall & Cameron-Smith, 2005). To bring about such modifications, a number of highly coordinated processes occur, including gene transcription, RNA transport from the nucleus, protein synthesis, and, in some cases, post-translational modification of the protein (Figure 2). However, the initiation of gene transcription is strongly related to both acute and chronic changes in dietary intake and composition (Jump & Clarke, 1999) and thus has the potential to modulate many of the adaptive responses to ...
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A single bout of resistance training induces residual fatigue, which may impair performance during subsequent endurance training if inadequate recovery is allowed. From a concurrent training standpoint, such carry-over effects of fatigue from a resistance training session may impair the quality of a subsequent endurance training session for several...
Citations
... Aside from glycogen synthesis, the consumption of protein and essential amino acids following exercise plays a pivotal role in triggering muscle protein synthesis and aiding in the reconditioning of skeletal muscles (183). After exercising, there is a notable increase in muscle damage and protein degradation in the aftermath of exercise (161,181). ...
... Moreover, when glycogen stores are depleted, the pace of protein breakdown increases, as amino acids could potentially undergo gluconeogenesis to be utilized in replenishing levels of glycogen (91). As a result, it is crucial to consume protein after exercise to mitigate the breakdown of proteins and assist in the repair of muscle damage (183). ...
Nutrition serves as the cornerstone of an athlete’s life, exerting a profound impact on their performance and overall well-being. To unlock their full potential, athletes must adhere to a well-balanced diet tailored to their specific nutritional needs. This approach not only enables them to achieve optimal performance levels but also facilitates efficient recovery and reduces the risk of injuries. In addition to maintaining a balanced diet, many athletes also embrace the use of nutritional supplements to complement their dietary intake and support their training goals. These supplements cover a wide range of options, addressing nutrient deficiencies, enhancing recovery, promoting muscle synthesis, boosting energy levels, and optimizing performance in their respective sports or activities. The primary objective of this narrative review is to comprehensively explore the diverse nutritional requirements that athletes face to optimize their performance, recovery, and overall well-being. Through a thorough literature search across databases such as PubMed, Google Scholar, and Scopus, we aim to provide evidence-based recommendations and shed light on the optimal daily intakes of carbohydrates, protein, fats, micronutrients, hydration strategies, ergogenic aids, nutritional supplements, and nutrient timing. Furthermore, our aim is to dispel common misconceptions regarding sports nutrition, providing athletes with accurate information and empowering them in their nutritional choices.
... Aside from glycogen synthesis, the consumption of protein and essential amino acids following exercise plays a pivotal role in triggering muscle protein synthesis and aiding in the reconditioning of skeletal muscles (183). After exercising, there is a notable increase in muscle damage and protein degradation in the aftermath of exercise (161,181). ...
... Moreover, when glycogen stores are depleted, the pace of protein breakdown increases, as amino acids could potentially undergo gluconeogenesis to be utilized in replenishing levels of glycogen (91). As a result, it is crucial to consume protein after exercise to mitigate the breakdown of proteins and assist in the repair of muscle damage (183). ...
Nutrition serves as the cornerstone of an athlete's life, exerting a profound impact on their performance and overall well-being. To unlock their full potential, athletes must adhere to a well-balanced diet tailored to their specific nutritional needs. This approach not only enables them to achieve optimal performance levels but also facilitates efficient recovery and reduces the risk of injuries. In addition to maintaining a balanced diet, many athletes also embrace the use of nutritional supplements to complement their dietary intake and support their training goals. These supplements cover a wide range of options, addressing nutrient deficiencies, enhancing recovery, promoting muscle synthesis, boosting energy levels, and optimizing performance in their respective sports or activities. The primary objective of this narrative review is to comprehensively explore the diverse nutritional requirements that athletes face to optimize their performance, recovery, and overall well-being. Through a thorough literature search across databases such as PubMed, Google Scholar, and Scopus, we aim to provide evidence-based recommendations and shed light on the optimal daily intakes of carbohydrates, protein, fats, micronutrients, hydration strategies, ergogenic aids, nutritional supplements, and nutrient timing. Furthermore, our aim is to dispel common misconceptions regarding sports nutrition, providing athletes with accurate information and empowering them in their nutritional choices.
... ,25 However, only a few studies have examined the effects of adequate hydration during labor in the past two decades. These studies have assessed the effects of IV fluids using different types and rates of IV fluids like ringer lactate, normal saline, and the addition of 5% dextrose.6 ...
Background
Evidence regarding the type and rate of intravenous (IV) fluid administration during labor is still inconclusive and the studies assessing the impact of IV fluids had mixed results.
Objectives
To evaluate the effects of IV fluids at an infusion rate of 250 mL/h as compared with 125 mL/h on labor outcomes in nulliparous women.
Search Strategy
We searched six databases for relevant studies through a search strategy containing the relevant keywords “IV hydration”, “IV fluids”, and “labor” from the inception of these databases to May 1, 2023, without any applied restrictions.
Selection Criteria
Search results were imported to Covidence for screening of eligible articles for this review. Randomized controlled trials (RCTs) assessing the impact of IV fluids at 250 mL/h on the outcomes of labor in nulliparous women at term (>37 weeks) as compared with 125 mL/h were included only.
Data Collection and Analysis
Data regarding the characteristics of included studies, participant's baseline characteristics, and concerned outcomes were collected in an Excel spreadsheet and all the concerned outcomes were pooled as risk ratios (RR) or mean difference (MD) with 95% confidence interval (CI) in the meta‐analysis models using RevMan 5.4.
Main results
Pooled data from 11 RCTs with 1815 patients showed that 250 mL/h infusion rate had a significant reduction in cesarean section rate (RR 0.70, 95% CI 0.56–0.88, P = 0.002), the first stage of labor duration (MD –46.97, 95% CI –81.79 to −12.14, P = 0.008), the second stage of labor duration (MD –2.69, 95% CI –4.34 to −1.05, P = 0.001), prolonged labor incidence (RR 0.72, 95% CI 0.58–0.89, P = 0.003), as compared with 125 mL/h. Also, the vaginal delivery rate (RR 1.07, 95% CI 1.02–1.12, P = 0.009) was higher with a 250 mL/h infusion rate.
Conclusion
IV fluids at an infusion rate of 250 mL/h during labor in nulliparous women decreased the cesarean delivery rate, increased the vaginal delivery rate, shortened the first and second‐stage labor duration, decreased the incidence of prolonged labor as compared with 125 mL/h. These findings suggest enhanced labor progression and a lower risk of labor complications with higher infusion rates. However, future research involving a more diverse population and exploring the potential benefits of combining IV infusion rates with other interventions, such as adding dextrose or less restrictive oral intake during labor, is needed.
... The lack of consistent findings in this review may be due to the multi-factorial nature of the load-response relationship. The individual response to training load is both positively and negatively influenced by factors such as physical qualities [6,117,118], stress [119], sleep [120], nutrition [121], and academic stress [122]. For example, one study found that self-esteem, sleep, and nutrition altered the injury rates in adolescent athletes in a multi-sport cohort [89]. ...
Background
With the increasing professionalisation of youth sports, training load monitoring is increasingly common in adolescent athletes. However, the research examining the relationship between training load and changes in physical qualities, injury, or illness in adolescent athletes is yet to be synthesised in a systematic review.
Objective
The aim of this review was to systematically examine the research assessing internal and external methods of monitoring training load and physical qualities, injury, or illness in adolescent athletes.
Methods
Systematic searches of SPORTDiscus, Web of Science, CINAHL and SCOPUS were undertaken from the earliest possible records to March 2022. Search terms included synonyms relevant to adolescents, athletes, physical qualities, injury, or illness. To be eligible for inclusion, articles were required to (1) be original research articles; (2) be published in a peer-reviewed journal; (3) include participants aged between 10 and 19 years and participating in competitive sport; (4) report a statistical relationship between a measure of internal and/or external load and physical qualities, injury or illness. Articles were screened and assessed for methodological quality. A best-evidence synthesis was conducted to identify trends in the relationships reported.
Results
The electronic search yielded 4125 articles. Following screening and a review of references, 59 articles were included. The most commonly reported load monitoring tools were session ratings of perceived exertion (n = 29) and training duration (n = 22). Results of the best-evidence synthesis identified moderate evidence of positive relationships between resistance training volume load and improvement in strength, and between throw count and injury. However, evidence for other relationships between training load and change in physical qualities, injury, or illness were limited or inconsistent.
Conclusions
Practitioners should consider monitoring resistance training volume load for strength training. Additionally, where appropriate, monitoring throw counts may be useful in identifying injury risk. However, given the lack of clear relationships between singular measures of training load with physical qualities, injury, or illness, researchers should consider multivariate methods of analysing training load, as well as factors that may mediate the load–response relationship, such as maturation.
... Die (Hawley et al. 2006). Dies kann von Bedeutung sein, wenn die Möglichkeit einer ausreichenden Kohlenhydrataufnahme eingeschränkt ist. ...
Unter einem „Übertrainingssyndrom“ versteht man einen unerwarteten Abfall der Leistungsfähigkeit ohne organisch krankhaften Befund, der auch nach einer längeren Regenerationsphase nachweisbar ist. Es existiert kein einzelner zuverlässiger Marker zur Diagnose von chronischen Überlastungszuständen. Die Diagnose eines Übertrainingssyndroms ist eine klinische Ausschlussdiagnose. Zur Prävention sind standardisierte Leistungstests und Fragebögen zur Erfassung der subjektiven Befindlichkeit mit Kenntnis individueller Basiswerte geeignet. Eine angemessene Ernährung, Kälteanwendungen, adäquater Schlaf sowie eine präventive individuelle Trainingsplanung und -dokumentation scheinen geeignete Möglichkeiten, die Erholung zu unterstützen und somit die Qualität des Trainings zu gewährleisten. Dieser Beitrag ist Teil der Sektion Sportmedizin, herausgegeben vom Teilherausgeber Holger HW Gabriel, innerhalb des Handbuchs Sport und Sportwissenschaft, herausgegeben von Arne Güllich und Michael Krüger.
... Properly balanced nutrition is one of the factors that support performance enhancement and post-exercise recovery [10,11]. An adequate nutrient supply contributes to training adaptation [12,13] and can have an impact on reducing the risk of injury and recovery time [14]. Training periods vary in terms of physiological demands and differences in energy expenditure generated. ...
The aim of this review was to determine whether male football players meet dietary recommendations according to a UEFA expert group statement and to identify priority areas for dietetic intervention, including training periodization and field position. A database search of PubMed, Web of Science, EBSCO and Scopus was performed. To be included within the final review, articles were required to provide a dietary intake assessment of professional and semi-professional football players. A total of 17 studies met the full eligibility criteria. Several studies showed insufficient energy and carbohydrate intake compared to the recommendations. A majority of athletes consume adequate protein and fat intakes compared to the recommendations. In addition, several studies showed the
insufficient intake of vitamins and minerals. This systematic review showed that football players do not meet the nutritional recommendations according to the UEFA expert group statement. Future research should be focused on how to apply nutritional recommendations specific for athletes in
accordance with training periodization and positions on the field.
... At the onset of exercise, calcium ions (Ca 2+ ) are released from the sarcoplasmic reticulum, muscle glycogenolytic rate and FFA availability are increased, and exercise metabolites are generated, such as lactate as well as reactive oxygen species, all of which serve to destabilise the cellular environment and induce specific signalling responses regulating skeletal muscle adaptation (Hawley, Tipton and Millard-Stafford, 2006). These exerciseinduced homeostatic perturbations result in the activation of specific protein kinases, including AMP-dependent protein kinase (AMPK), Ca 2+ /calmodulin dependent protein kinase II (CaMKII) and p38 mitogen-activated protein kinase (p38 MAPK). ...
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.
... Chronic strategies are typically aimed at progressive adaptations that occur in response to repeat bouts of exercise, over extended periods (17), whereas acute strategies provide more transient responses and are implemented with the goal of producing a rapid, short-term effect (3,22,24). Current research into the use of acute preparation strategies largely focuses on individual modalities (i.e., exercise, nutrition, psychology, etc.) and their impact on performance, with the decision to implement such strategies often determined by factors such as logistics, resources, personal coach preference, and philosophy, or the level of competition (32). ...
The aim of this study was to identify game day preparation strategies used by performance staff to improve team sport performance and to determine consensus regarding the application and importance of these strategies. Twenty-five performance staff working in high performance or professional team sports participated in this Delphi study, which implemented 3 survey rounds. The first round sought responses to open-ended questions relating to the use of game day preparation strategies. These responses were developed into statements and recirculated (round-2 survey), with subjects asked to rate their level of agreement with each statement. The third and final survey presented revised versions of statements that did not reach a consensus in the previous round, along with new statements derived from subject responses. A thematic analysis of the open-ended responses in the first survey identified 5 key themes relating to game day preparation strategies: “exercise,” “nutrition,” “psychological,”
“technical and tactical,” and “other.” The round-2 survey included 38 statements across the 5 themes, with 22 reaching the consensus threshold ($75%) for agreement. The remaining 16 statements did not reach consensus. The final survey included 18 statements (16 revised and 2 new) with 12 reaching the consensus threshold for agreement. Key preparation strategies identified in this study include structured and progressive warm-ups, strength and power–based priming sessions, individualized nutrition plans, and precooling in hot conditions. Performance staff working in similar environments should
consider adopting these strategies to improve athlete or team performance.
... There is evidence that the fold change in MPS in response to REx and/or protein feeding is greater (as much as 2.5-fold) than muscle protein breakdown (Biolo et al., 1995(Biolo et al., , 1997, suggesting that MPS is the primary metabolic driver of RETinduced muscle hypertrophy (Tipton & Wolfe, 1998). Accordingly, it has been proposed that muscle hypertrophy following RET stems from a cumulative accretion of muscle proteins resulting from the repeated increase in response of myofibrillar-MPS to successive bouts of REx (Hawley et al., 2006). Hence, according to this traditional definition of muscle hypertrophy, it may seem intuitively satisfying that assessment of the acute response of MPS to REx provides an informative tool when devising RET and nutritional interventions to maximize muscle hypertrophy in athletes and other exercisers. ...
The acute response of muscle protein synthesis (MPS) to resistance exercise and nutrition is often used to inform recommendations for exercise programming and dietary interventions, particularly protein nutrition, to support and enhance muscle growth with training. Those recommendations are worthwhile only if there is a predictive relationship between the acute response of MPS and subsequent muscle hypertrophy during resistance exercise training. The metabolic basis for muscle hypertrophy is the dynamic balance between the synthesis and degradation of myofibrillar proteins in muscle. There is ample evidence that the process of MPS is much more responsive to exercise and nutrition interventions than muscle protein breakdown. Thus, it is intuitively satisfying to translate the acute changes in MPS to muscle hypertrophy with training over a longer time frame. Our aim is to examine and critically evaluate the strength and nature of this relationship. Moreover, we examine the methodological and physiological factors related to measurement of MPS and changes in muscle hypertrophy that contribute to uncertainty regarding this relationship. Finally, we attempt to offer recommendations for practical and contextually relevant application of the information available from studies of the acute response of MPS to optimize muscle hypertrophy with training.
... Increased uid intake has been shown to improve the performance of skeletal muscle during long periods of exercise [7, 8]. Extrapolation of these data to uterine smooth muscle could explain the inadequate hydration affecting women who experience prolonged labor [9]. ...
Background
Effective myometrial contractility is important for successful labor, although little attention has been paid to the effect of managing intrapartum fluid intake. Ineffective myometrial contractility leads to prolonged labor, thus increasing obstetric and neonatal adverse outcomes. The risk of prolonged labor can be reduced by increasing the total volume of fluids administered during labor.
Objective
To determine the hydration strategies applied in nulliparous women undergoing low risk labor and their association with obstetric and neonatal outcomes.
Methods
A prospective cohort study was conducted in a Universitary Hospital. The study population included nulliparous women who presented in active labor or induced labor. Sample size was 147. In order to stratify women based on the hydration received, we set as a cut-off point the mean total volume administered per hour (300 ml/h). This enabled to compare obstetric, clinical, and neonatal outcomes in women who had received ≥ 300 mL/h o < 300 mL/h. The primary outcome was total length of labor. Secondary outcomes included maternal and neonatal outcomes.
Results
The study population comprised 148 nulliparous women, mean (DS) age 32.2 (4.4) years, mean (DS) gestational age of 39.4 (1.41) weeks. At admission, median (IQR) dilation was 2 (1–3) cm. Labor was induced in 65.5% (n = 97). Obstetric and neonatal outcomes were more favorable in women who received a ≥ 300 mL/h volume, with statistically significant median differences in the duration total duration of labor (526 vs 735 min; p < 0.001). Clinically relevant differences were also observed with respect to cesarean delivery (14.3% vs 18.7%), fever (5.5% vs 7.7%), weight loss at 24 hours (–2.3% vs − 3%) and at 48 hours (–5.7% vs − 6.3 %), incidence of weight loss > 7% at 48 hours (28.6% vs 39.8%), breastfeeding (94.6% vs 82.4%).
Conclusions
Higher fluid volume administered to nulliparous women during low-risk labor is associated with improved obstetric and neonatal outcomes.
