Ketogenic and athletes

Reviews focused on the ketogenic diet (KD) based on the increase in fat-free mass (FFM) have been carried out with pathological populations or, failing that, without population differentiation. The aim of this review and meta-analysis was to verify whether a ketogenic diet without programmed energy restriction generates increases in fat-free mass (FFM) in resistance-trained participants. We evaluated the effect of the ketogenic diet, in conjunction with resistance training, on fat-free mass in trained participants...

The ketone bodies acetoacetate (AcAc) and β-hydroxybutyrate (βHB) have pleiotropic effects in multiple organs including brain, heart, and skeletal muscle by serving as an alternative substrate for energy provision, and by modulating inflammation, oxidative stress, catabolic processes, and gene expression. Of particular relevance to athletes are the metabolic actions of ketone bodies to alter substrate utilisation through attenuating glucose utilisation in peripheral tissues, anti-lipolytic effects on adipose tissue, and attenuation of proteolysis in skeletal muscle...

(1) Background: Recently, studies have emerged to explore the effects of concurrent training (CT) with a low-carb, high-fat ketogenic diet (LCHF) on body composition and aerobic performance and observed its benefits. However, a large variance in the study design and observations is presented, which needs to be comprehensively assessed. We here thus completed a systematic review and meta-analysis to characterize the effects of the intervention combining CT and LCHF on body composition and aerobic capacity in people with training experience as compared to that combining CT and other dietary strategies...

As humans age, we lose skeletal muscle mass, even in the absence of disease (sarcopenia), increasing the risk of death. Low mitochondrial mass and activity contributes to sarcopenia. It is our hypothesis that a ketogenic diet improves skeletal muscle mitochondrial mass and function when they have declined because of aging or disease, but not in athletes where mitochondrial quality is high.

BACKGROUND: Frequent dieting is common in athletes attempting to achieve a body composition perceived to improve performance. Excessive dieting may indicate disordered eating (DE) behaviors and can result in clinical eating disorders. However, the current nutrition patterns that underly dieting culture are underexplored in endurance athletes. Therefore, the purpose of this study was to identify the sex differences in nutrition patterns among a group of endurance athletes. METHODS: Two-hundred and thirty-one endurance athletes (females = 124) completed a questionnaire regarding their dieting patterns and associated variables...

This systematic review with meta-analysis aimed to determine the effects of the ketogenic diet (KD) against carbohydrate (CHO)-rich diets on physical performance and body composition in trained individuals. The MEDLINE, EMBASE, CINAHL, SPORTDiscus, and The Cochrane Library were searched. Randomized and non-randomized controlled trials in athletes/trained adults were included. Meta-analytic models were carried out using Bayesian multilevel models. Eighteen studies were included providing estimates on cyclic exercise modes and strength one-maximum repetition (1-RM) performances and for total, fat, and free-fat masses...

Elevating blood ketones may enhance exercise capacity and modulate adaptations to exercise training; however, these effects may depend on whether hyperketonemia is induced endogenously through dietary carbohydrate restriction, or exogenously through ketone supplementation. To determine this, we compared the effects of endogenously- and exogenously-induced hyperketonemia on exercise capacity and adaptation. Trained endurance athletes undertook 6 days of laboratory based cycling ("race") whilst following either: a carbohydrate-rich control diet (n = 7; CHO); a carbohydrate-rich diet + ketone drink four-times daily (n = 7; Ex Ket); or a ketogenic diet (n = 7; End Ket)...

Evidence shows that the use of food strategies can impact health, but a clear consensus about how the effects of different food strategies impact improvement in the athlete's performance and health remain unclear. This study evaluated how food strategies, specifically intermittent fasting and a ketogenic diet affect health and performance in healthy athletes. Study selection for this review was based on clinical trial studies analyzing changes in performance and health in athletes. The Pubmed, Web of Science, PEDro, Dialnet, Scopus, CINAHL, ProQuest, Medline and Cochrane databases were searched...

Background: The ketogenic diet (KD) has been used for almost 100 years in the treatment of drug-resistant epilepsy in children - and adults. The intestinal microbiome has a climax character, and the main factor changing its composition and functions is the diet. Both increased biodiversity and the production of short-chain fatty acids (SCFAs) are important indicators of gut barrier function. SCFAs are synthesized by microorganisms through the fermentation of dietary fibre provided with the diet...

This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk)...

NEW FINDINGS: What is the topic of this review? The nutritional strategies that athletes use during competition events to optimize performance and the reasons they use them. What advances does it highlight? A range of nutritional strategies can be used by competitive athletes, alone or in combination, to address various event-specific factors that constrain event performance. Evidence for such practices is constantly evolving but must be combined with understanding of the complexities of real-life sport for optimal implementation...

BACKGROUND: A ketogenic diet (KD) is a nutritional approach, usually adopted for weight loss, that restricts daily carbohydrates under 30 g/day. KD showed contradictory results on sport performance, whilst no data are available on team sports. We sought to investigate the influence of a KD on different parameters in semi-professional soccer players. METHODS: Subjects were randomly assigned to a iso-protein (1.8 g/Kg body weight/day) ketogenic diet (KD) or western diet (WD) for 30 days...

Endurance athletes may implement rigid dietary strategies, such as the ketogenic diet (KD), to improve performance. The effect of the KD on appetite remains unclear in endurance athletes. This study analyzed the effects of a KD, a high-carbohydrate diet (HCD), and habitual diet (HD) on objective and subjective measures of appetite in trained cyclists and triathletes, and hypothesized that the KD would result in greater objective and subjective appetite suppression. Six participants consumed the KD and HCD for 2-weeks each, in a random order, following their HD...

A low-carbohydrate, high-fat (LCHF) diet has been proposed to enhance the fat utilization of muscle and the aerobic capacity of endurance athletes, thereby improving their exercise performance. However, it remains uncertain how the macronutrient intake shift from carbohydrate to fat affects endurance exercise training and performance. This study performed a systematic review and meta-analysis to explore the effects of a ketogenic low-carbohydrate, high-fat (K-LCHF) diet on aerobic capacity and exercise performance among endurance athletes...

OBJECTIVES: Both exercise and a ketogenic (low-carbohydrate) diet favor glycogen depletion and increase ammonemia, which can impair physical performance. Caffeine supplementation has been routinely used to improve exercise performance. Herein, the effect of xanthine was evaluated on ammonemia in cyclists who were placed on a ketogenic diet and engaged in prolonged exercise. METHODS: Fourteen male cyclists followed a ketogenic diet for 2 d before and during the experimental trial...

Obesity remains a serious relevant public health concern throughout the world despite related countermeasures being well understood (i.e. mainly physical activity and an adjusted diet). Among different nutritional approaches, there is a growing interest in ketogenic diets (KD) to manipulate body mass (BM) and to enhance fat mass loss. KD reduce the daily amount of carbohydrate intake drastically. This results in increased fatty acid utilisation, leading to an increase in blood ketone bodies (acetoacetate, 3-β-hydroxybutyrate and acetone) and therefore metabolic ketosis...

We previously reported that consuming a ketogenic diet containing medium-chain triacylglycerols (MCTs) might be a valuable dietary strategy for endurance athletes. However, the long-term safety of the diet has not been established, and there is a concern that a higher intake of MCTs increases the liver triacylglycerol content. In this study, we found that consuming an MCT-containing ketogenic diet for 24 weeks decreased, rather than increased, the liver triacylglycerol concentration and did not aggravate safety-related blood biomarkers in male Wistar rats...

BACKGROUND: To achieve ideal strength/power to mass ratio, athletes may attempt to lower body mass through reductions in fat mass (FM), while maintaining or increasing fat-free mass (FFM) by manipulating their training regimens and diets. Emerging evidence suggests that consumption of high-fat, ketogenic diets (KD) may be advantageous for reducing body mass and FM, while retaining FFM. METHODS: A systematic review of the literature was conducted using PubMed and Cochrane Library databases to compare the effects of KD versus control diets (CON) on body mass and composition in physically active populations...

PURPOSE: Considerable interindividual heterogeneity has been observed in endurance performance responses following induction of a ketogenic diet (KD). It is plausible that a physiological stress response in the period following the dramatic dietary shift associated with transition to a KD may explain this heterogeneity. METHODS: In a randomized, crossover study design, 8 trained male runners completed an incremental exercise test and ran to exhaustion at 70%VO2max before and after a 31-day rigorously controlled habitual diet or KD intervention, and recorded heart rate variability (root mean square of the sum of successive differences in R-R intervals [rMSSD]) upon waking each morning along with the recovery-stress questionnaire for athletes each week...

(1) Background: The purpose of the current meta-analysis was to investigate any positive or negative effects of ketogenic diets in athletes and provide an assessment of the size of these effects. (2) Methods: Databases were used to select relevant studies up to January 2021 regarding the effects of ketogenic diets in athletes. Inclusion criteria were as follows: data before and after ketogenic diet use, being randomized controlled trials and presenting ketogenic diets and assessments of ketone status. Study subjects were required to be professional athletes...