Acute Ketogenic Diet and Ketone Ester Supplementation Impairs Race Walk Performance

Whitfield, Jamie; Burke, Louise M.; McKay, Alannah K A; Heikura, Ida A.; Hall, Rebecca; Fensham, Nikita C.; Sharma, Avish P.

doi:10.1249/mss.0000000000002517

Cited by 29 publications

(41 citation statements)

References 37 publications

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“…Differences in exercise economy due to the choice of muscle substrate have also received recent attention following consistent findings from studies from our group [ 24 , 25 , 26 , 27 ] and others [ 28 ] that the substantial increase in muscle fat oxidation achieved by adaptation to a ketogenic low-carbohydrate (CHO), high-fat diet is associated with an increase in the oxygen cost of exercise at speeds which are relevant to the race performance of elite endurance athletes [ 29 ]. Indeed, as demonstrated more than a century ago [ 30 , 31 ], and explained by the stoichiometry of oxidative reactions [ 32 ], CHO oxidation produces 5–8% higher energy yield per litre of oxygen consumed through oxidative phosphorylation.…”

Section: Introductionsupporting

confidence: 64%

Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers

et al. 2021

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Given the importance of exercise economy to endurance performance, we implemented two strategies purported to reduce the oxygen cost of exercise within a 4 week training camp in 21 elite male race walkers. Fourteen athletes undertook a crossover investigation with beetroot juice (BRJ) or placebo (PLA) [2 d preload, 2 h pre-exercise + 35 min during exercise] during a 26 km race walking at speeds simulating competitive events. Separately, 19 athletes undertook a parallel group investigation of a multi-pronged strategy (MAX; n = 9) involving chronic (2 w high carbohydrate [CHO] diet + gut training) and acute (CHO loading + 90 g/h CHO during exercise) strategies to promote endogenous and exogenous CHO availability, compared with strategies reflecting lower ranges of current guidelines (CON; n = 10). There were no differences between BRJ and PLA trials for rates of CHO (p = 0.203) or fat (p = 0.818) oxidation or oxygen consumption (p = 0.090). Compared with CON, MAX was associated with higher rates of CHO oxidation during exercise, with increased exogenous CHO use (CON; peak = ~0.45 g/min; MAX: peak = ~1.45 g/min, p < 0.001). High rates of exogenous CHO use were achieved prior to gut training, without further improvement, suggesting that elite athletes already optimise intestinal CHO absorption via habitual practices. No differences in exercise economy were detected despite small differences in substrate use. Future studies should investigate the impact of these strategies on sub-elite athletes’ economy as well as the performance effects in elite groups.

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Section: Introductionsupporting

confidence: 64%

Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers

et al. 2021

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“…The potential benefits of greater inclusion of women in SSSM research and more targeted research on female athletes include better athletic performance, safer athlete practices, greater parity in access to resources and opportunities, and an increase in general SSSM knowledge and expertise. Acute ketogenic diet and ketone ester supplementation impairs race walk performance (Whitfield et al, 2021) Elite race walkers undertook a four-stage exercise economy test and real-life 10,000 m race before and after a 5-day isoenergetic high-or low-carbohydrate, high-fat diet Performance A 10,000-m race is a performance measure B-Alanine supplementation's improvement of high-intensity game activities in Water Polo (Brisola et al, 2018) The participants performed a simulated water polo game before and after the supplementation period Performance A simulated match scenario is a performance measure…”

Section: Discussionmentioning

confidence: 99%

Methodology Review: A Protocol to Audit the Representation of Female Athletes in Sports Science and Sports Medicine Research

Smith

McKay

Ackerman

et al. 2022

International Journal of Sport Nutrition and Exercise Metabolism

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Female-specific research on sports science and sports medicine (SSSM) fails to mirror the increase in participation and popularity of women’s sport. Females have historically been excluded from SSSM research, particularly because their physiological intricacy necessitates more complex study designs, longer research times, and additional costs. Consequently, most SSSM practices are based on research with men, despite potential problems in translation to females due to sexual dimorphism in biological and phenotypical parameters as well as differences in event characteristics (e.g., race distances/durations). Recognition that erroneous extrapolations may hamper the efforts of females to maximize their athletic potential has created an impetus to acknowledge and readdress the sex disparity in SSSM research. To direct the priorities for future research, it is prudent to first develop a comprehensive understanding of the gaps in current knowledge by systematically “auditing” the literature. By conducting audits of the literature to highlight underdeveloped topics or identify potential problems with the quality of research, this information can then be used to expediently direct new research activities. This paper therefore presents a standardized audit methodology to establish the representation of female athletes in subdisciplines of existing SSSM research, including a template for reporting the results of key metrics. This standardized audit process will enable comparisons over time and between research subdisciplines. This working guide provides an important step toward achieving sex equity across SSSM research, with the eventual goal of providing evidence-based recommendations specific to the female athlete.

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“…The metabolic contribution of ketone bodies as a potent metabolic fuel for energy expenditure during exercise and physical activity is an area of increasing attention in the field of exercise physiology and sport nutrition in recent years. However, recent evidence questions the potential ergogenic benefits of low carbohydrate ketogenic diets and exogenous ketone supplementation on endurance-type exercise [ 193 , 195 ], and the potential negative health consequences [ 196 ].…”

Section: Other Energy Provision Sourcesmentioning

confidence: 99%

Regulation of Energy Substrate Metabolism in Endurance Exercise

Alghannam

Ghaith

Alhussain

2021

IJERPH

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The human body requires energy to function. Adenosine triphosphate (ATP) is the cellular currency for energy-requiring processes including mechanical work (i.e., exercise). ATP used by the cells is ultimately derived from the catabolism of energy substrate molecules—carbohydrates, fat, and protein. In prolonged moderate to high-intensity exercise, there is a delicate interplay between carbohydrate and fat metabolism, and this bioenergetic process is tightly regulated by numerous physiological, nutritional, and environmental factors such as exercise intensity and duration, body mass and feeding state. Carbohydrate metabolism is of critical importance during prolonged endurance-type exercise, reflecting the physiological need to regulate glucose homeostasis, assuring optimal glycogen storage, proper muscle fuelling, and delaying the onset of fatigue. Fat metabolism represents a sustainable source of energy to meet energy demands and preserve the ‘limited’ carbohydrate stores. Coordinated neural, hormonal and circulatory events occur during prolonged endurance-type exercise, facilitating the delivery of fatty acids from adipose tissue to the working muscle for oxidation. However, with increasing exercise intensity, fat oxidation declines and is unable to supply ATP at the rate of the exercise demand. Protein is considered a subsidiary source of energy supporting carbohydrates and fat metabolism, contributing to approximately 10% of total ATP turnover during prolonged endurance-type exercise. In this review we present an overview of substrate metabolism during prolonged endurance-type exercise and the regulatory mechanisms involved in ATP turnover to meet the energetic demands of exercise.

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Acute Ketogenic Diet and Ketone Ester Supplementation Impairs Race Walk Performance

Abstract: Supplemental digital content is available in the text.

Cited by 29 publications

References 37 publications

Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers

Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers

Methodology Review: A Protocol to Audit the Representation of Female Athletes in Sports Science and Sports Medicine Research

Regulation of Energy Substrate Metabolism in Endurance Exercise

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