Search Results

You are looking at 1 - 10 of 25 items for :

  • Refine by Access: All Content x
Clear All
Open access

Acute Ingestion of Ketone Monoesters and Precursors Do Not Enhance Endurance Exercise Performance: A Systematic Review and Meta-Analysis

Emma Brooks, Gilles Lamothe, Taniya S. Nagpal, Pascal Imbeault, Kristi Adamo, Jameel Kara, and Éric Doucet

) diet ( Cox & Clarke, 2014 ; Robinson & Williamson, 1980 ). Under all of these circumstances, KBs become a pertinent energy source while glucose is restricted or depleted. Ketosis, or hyperketonaemia, is defined as plasma ketone concentrations that exceed 0.2 mM, according to Robinson and Williamson

Free access

Effects of Ketone Monoester and Bicarbonate Co-Ingestion on Cycling Performance in WorldTour Cyclists

Domingo Jesús Ramos-Campo, Francisco Javier López-Román, Silvia Pérez-Piñero, Raquel Ortolano, María Salud Abellán-Ruiz, Enrique Molina Pérez de los Cobos, Antonio Jesús Luque-Rubia, Dag Van Elslande, and Vicente Ávila-Gandía

and the heart, with greater contribution observed in exogenous ketosis ( Evans et al., 2017 ). Hyperketonemia is defined as a plasma ketone concentration above 0.5 mM ( Robinson & Williamson, 1980 ). β-Hydroxybutyrate (βHB) is the most common circulating ketone body, and exogenous ketones are often

Open access

The Effect of 1,3-Butanediol on Cycling Time-Trial Performance

David M. Shaw, Fabrice Merien, Andrea Braakhuis, Daniel Plews, Paul Laursen, and Deborah K. Dulson

. , Ashmore , T. , Willerton , K. , Evans , R. , Smith , A. , . . . Clarke , K. ( 2016 ). Nutritional ketosis alters fuel preference and thereby endurance performance in athletes . Cell Metabolism, 24 ( 2 ), 256 – 268 . PubMed ID: 27475046 doi:10.1016/j.cmet.2016.07.010 10.1016/j.cmet.2016

Restricted access

Acute Ketone Salts–Caffeine–Taurine–Leucine Supplementation but not Ketone Salts–Taurine–Leucine, Improves Endurance Cycling Performance

Manuel D. Quinones and Peter W.R. Lemon

endurance exercise performance because the resulting upregulated fat mobilization triggers a substantial increased accumulation of circulating ketone bodies. This is called nutritional ketosis ( Evans et al., 2017 ) and is characterized typically by a plasma ketone concentration of approximately 0.5–3.0 mM

Restricted access

Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Pedro L. Valenzuela, Javier S. Morales, Adrián Castillo-García, and Alejandro Lucia

gastrointestinal symptoms might not necessarily contribute to the lack of significant ergogenic effects of ketone supplements. The type and dose of ketone supplements might also influence their effects on performance and on the physiological responses to exercise, with a minimal ketosis state being potentially

Restricted access

Autonomic and Perceptual Responses to Induction of a Ketogenic Diet in Free-Living Endurance Athletes: A Randomized, Crossover Trial

Ed Maunder, Deborah K. Dulson, and David M. Shaw

. Ryan KK , Packard AEB , Larson KR , et al . Dietary manipulations that induce ketosis activate the HPA axis in male rats and mice: a potential role for fibroblast growth factor-21 . Endocrinology . 2018 ; 159 ( 1 ): 400 – 413 . PubMed ID: 29077838 doi:10.1210/en.2017-00486 29077838 10

Restricted access

Metabolism and Whole-Body Fat Oxidation Following Postexercise Carbohydrate or Protein Intake

Ulrika Andersson-Hall, Stefan Pettersson, Fredrik Edin, Anders Pedersen, Daniel Malmodin, and Klavs Madsen

protein after the first session did not significantly affect this increase in fat oxidation, whereas maltodextrin intake somewhat attenuated the increase in fat oxidation during the second bout. Both PRO and CHO intake increased blood insulin levels and attenuated the postexercise ketosis seen after

Restricted access

Fat-Free Mass Changes During Ketogenic Diets and the Potential Role of Resistance Training

Grant M. Tinsley and Darryn S. Willoughby

Low-carbohydrate and very-low-carbohydrate diets are often used as weight-loss strategies by exercising individuals and athletes. Very-low-carbohydrate diets can lead to a state of ketosis, in which the concentration of blood ketones (acetoacetate, 3-β-hydroxybutyrate, and acetone) increases as a result of increased fatty acid breakdown and activity of ketogenic enzymes. A potential concern of these ketogenic diets, as with other weight-loss diets, is the potential loss of fat-free mass (e.g., skeletal muscle). On examination of the literature, the majority of studies report decreases in fat-free mass in individuals following a ketogenic diet. However, some confounding factors exist, such as the use of aggressive weight-loss diets and potential concerns with fat-free mass measurement. A limited number of studies have examined combining resistance training with ketogenic diets, and further research is needed to determine whether resistance training can effectively slow or stop the loss of fat-free mass typically seen in individuals following a ketogenic diet. Mechanisms underlying the effects of a ketogenic diet on fat-free mass and the results of implementing exercise interventions in combination with this diet should also be examined.

Restricted access

Exogenous Ketone Salts Do Not Improve Cognitive Performance During a Dual-Stress Challenge

Hunter S. Waldman, Brandon D. Shepherd, Brendan Egan, and Matthew J. McAllister

ester forms, it is specifically the (R)-3-hydroxybutyl (R)-3-hydroxybutyrate ketone monoester (KME) that produces dramatically higher plasma D -β-OHB concentrations (1.0–6.0 mM; Cox et al., 2016 ; Evans & Egan, 2018 ; Holdsworth et al., 2017 ). Inducing a state of nutritional ketosis (plasma D -β

Open access

Gastrointestinal Effects of Exogenous Ketone Drinks are Infrequent, Mild, and Vary According to Ketone Compound and Dose

Brianna J. Stubbs, Pete J. Cox, Tom Kirk, Rhys D. Evans, and Kieran Clarke

ketone drinks has grown ( Egan & D’Agostino, 2016 ). These drinks rapidly increase blood ketone concentrations to achieve ketosis (blood d -βHB >0.5 mM) without dietary modification ( Stubbs et al., 2017 ). Two classes of exogenous ketone compounds exist: ketone esters and ketone salts (KS). Ketone