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Keto-adaptation enhances exercise performance and body composition responses to training in endurance athletes

Published:November 03, 2017DOI:https://doi.org/10.1016/j.metabol.2017.10.010

      Abstract

      Background

      Low-carbohydrate diets have recently grown in popularity among endurance athletes, yet little is known about the long-term (>4 wk) performance implications of consuming a low-carbohydrate high fat ketogenic diet (LCKD) in well-trained athletes.

      Methods

      Twenty male endurance-trained athletes (age 33 ± 11 y, body mass 80 ± 11 kg; BMI 24.7 ± 3.1 kg/m2) who habitually consumed a carbohydrate-based diet, self-selected into a high-carbohydrate (HC) group (n = 11, %carbohydrate:protein:fat = 65:14:20), or a LCKD group (n = 9, 6:17:77). Both groups performed the same training intervention (endurance, strength and high intensity interval training (HIIT)). Prior to and following successful completion of 12-weeks of diet and training, participants had their body composition assessed, and completed a 100 km time trial (TT), six second (SS) sprint, and a critical power test (CPT). During post-intervention testing the HC group consumed 30–60 g/h carbohydrate, whereas the LCKD group consumed water, and electrolytes.

      Results

      The LCKD group experienced a significantly greater decrease in body mass (HC −0.8 kg, LCKD −5.9 kg; P = 0.006, effect size (ES): 0.338) and percentage body fat percentage (HC −0.7%, LCKD −5.2%; P = 0.008, ES: 0.346). Fasting serum beta-hydroxybutyrate (βHB) significantly increased from 0.1 at baseline to 0.5 mmol/L in the LCKD group (P = 0.011, ES: 0.403) in week 12. There was no significant change in performance of the 100 km TT between groups (HC −1.13 min·s, LCKD −4.07 min·s, P = 0.057, ES: 0.196). SS sprint peak power increased by 0.8 watts per kilogram bodyweight (w/kg) in the LCKD group, versus a −0.1 w/kg reduction in the HC group (P = 0.025, ES: 0.263). CPT peak power decreased by −0.7 w/kg in the HC group, and increased by 1.4 w/kg in the LCKD group (P = 0.047, ES: 0.212). Fat oxidation in the LCKD group was significantly greater throughout the 100 km TT.

      Conclusions

      Compared to a HC comparison group, a 12-week period of keto-adaptation and exercise training, enhanced body composition, fat oxidation during exercise, and specific measures of performance relevant to competitive endurance athletes.

      Keywords

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      References

        • Rodriguez N.R.
        • DiMarco N.M.
        • Langley S.
        Position of the American dietetic association, dietitians of Canada, and the American college of sports medicine: nutrition and athletic performance.
        J Am Diet Assoc. 2009; 109: 509-527
        • Jeukendrup A.
        A step towards personalized sports nutrition: carbohydrate intake during exercise.
        Sports Med. 2014; 44: 25-33https://doi.org/10.1007/s40279-014-0148-z
        • Burke L.M.
        Re-examining high-fat diets for sports performance: did we call the ‘nail in the coffin’ too soon?.
        Sports Med. 2015; 45: 33-49https://doi.org/10.1007/s40279-015-0393-9
        • Volek J.S.
        • Noakes T.
        • Phinney S.D.
        Rethinking fat as a fuel for endurance exercise.
        Eur J Sport Sci. 2015; 15: 13-20
        • Volek J.
        • Phinney S.D.
        The art and science of low-carbohydrate performance: a revolutionary program to extend your physical and mental performance envelope.
        in: Beyond obesity. 2012
        • Rapoport B.I.
        Metabolic factors limiting performance in marathon runners.
        PLoS Comput Biol. 2010; 6e1000960https://doi.org/10.1371/journal.pcbi.1000960
        • Burke L.M.
        • Hawley J.A.
        • Wong S.H.
        • Jeukendrup A.E.
        Carbohydrates for training and competition.
        J Sports Sci. 2011; 29: S17-S27https://doi.org/10.1080/02640414.2011.585473
        • Volek J.S.
        • Freidenreich D.J.
        • Saenz C.
        • Kunces L.J.
        • Creighton B.C.
        • Bartley J.M.
        • et al.
        Metabolic characteristics of keto-adapted ultra-endurance runners.
        Metabolism. 2016; 65: 100-110https://doi.org/10.1016/j.metabol.2015.10.028
        • Phinney S.D.
        • Bistrian B.R.
        • Evans W.J.
        • Gervino E.
        • Blackburn G.L.
        The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation.
        Metabolism. 1983; 32: 769-776https://doi.org/10.1016/0026-0495(83)90106-3
        • Paoli A.
        • Grimaldi K.
        • D'Agostino D.
        • Cenci L.
        • Moro T.
        • Bianco A.
        • et al.
        Ketogenic diet does not affect strength performance in elite artistic gymnasts.
        J Int Soc Sports Nutr. 2012; 9: 34https://doi.org/10.1186/1550-2783-9-34
        • Zajac A.
        • Poprzecki S.
        • Maszczyk A.
        • Czuba M.
        • Michalczyk M.
        • Zydek G.
        The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists.
        Forum Nutr. 2014; 6: 2493-2508https://doi.org/10.3390/nu6072493
        • Burke L.M.
        • Ross M.
        • Garvican-Lewis L.
        • Welvaert M.
        • Heikura I.
        • Forbes S.
        • et al.
        Low-carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers.
        J Physiol. 2017; https://doi.org/10.1113/JP273230
        • O'Keeffe K.A.
        • Keith R.E.
        • Wilson G.D.
        • Blessing D.L.
        Dietary carbohydrate intake and endurance exercise performance of trained female cyclists.
        Nutr Res. 1989; 9: 819-830https://doi.org/10.1016/S0271-5317(89)80027-2
        • Lambert E.
        • Speechly D.
        • Dennis S.
        Enhanced endurance in trained cyclists during moderate intensity exercise following 2 weeks adaptation to a high fat diet.
        Eur J Appl Physiol. 1994; 63: 287-293https://doi.org/10.1007/BF00392032
        • Goedecke J.
        • Christie C.
        • Wilson G.
        • Dennis S.
        Metabolic adaptations to a high-fat diet in endurance cyclists.
        Metabolism. 1999; https://doi.org/10.1016/S0026-0495(99)90238-X
        • Rowlands D.S.
        • Hopkins W.G.
        Effects of high-fat and high-carbohydrate diets on metabolism and performance in cycling.
        Metabolism. 2002; 51: 678-690https://doi.org/10.1053/meta.2002.32723
        • Vogt M.
        • Puntschart A.
        • Howald H.
        • Mueller B.
        Effects of dietary fat on muscle substrates, metabolism, and performance in athletes.
        Med Sci. 2003; https://doi.org/10.1249/01.MSS.0000069336.30649.BD
        • Venables M.C.
        • Achten J.
        • Jeukendrup A.E.
        Determinants of fat oxidation during exercise in healthy men and women: a cross-sectional study.
        J Appl Physiol. 2005; 98: 160-167https://doi.org/10.1152/japplphysiol.00662.2003
        • Noakes T.D.
        • Windt J.
        Evidence that supports the prescription of low-carbohydrate high-fat diets: a narrative review.
        Br J Sports Med. 2017; 51: 133-139
        • Webster C.C.
        • Noakes T.D.
        • Chacko S.K.
        • Swart J.
        • Kohn T.A.
        • Smith J.A.
        Gluconeogenesis during endurance exercise in cyclists habituated to a long-term low carbohydrate high-fat diet.
        J Physiol. 2016; 594: 4389-4405
        • Hokper J.
        • Myers S.
        • Jobson S.A.
        • Bruce W.
        • Passfield L.
        Validity and reliability of the wattbike cycle ergometer.
        Int J Sports Med. 2010; 31: 731-736
        • Hood M.S.
        • Little J.P.
        • Tarnopolsky M.A.
        • Myslik F.
        • Gibala M.J.
        Low-volume interval training improves muscle oxidative capacity in sedentary adults.
        Med Sci Sports Exerc. 2011; 43: 1849-1856https://doi.org/10.1249/MSS.0b013e3182199834
        • Wang L.
        • Mascher H.
        • Psilander N.
        • Blomstrand E.
        • Sahlin K.
        Resistance exercise enhances the molecular signaling of mitochondrial biogenesis induced by endurance exercise in human skeletal muscle.
        J Appl Physiol. 2011; 111: 1335-1344https://doi.org/10.1152/japplphysiol.00086.2011
        • Spreit L.L.
        New insights into the interaction of carbohydrate and fat metabolism during exercise.
        Sports Med. 2014; 44: 87-96
        • Cohen J.
        Statistical power analysis for the behavioural sciences.
        2nd ed. Erlbaum, Hillsdale, NJ1988
        • Rønnestad B.R.
        • Mujika I.
        Optimizing strength training for running and cycling endurance performance: a review.
        Scand J Med Sci Sports. 2014; 24: 603-612
        • Saunders P.U.
        • Pyne D.B.
        • Telford R.D.
        • Hawley J.A.
        Factors affecting running economy in trained distance runners.
        Sports Med. 2004; 34: 465-485
        • Helge J.W.
        A high carbohydrate diet remains the evidence based choice for elite athletes to optimise performance.
        J Physiol. 2017; https://doi.org/10.1113/JP273830
        • Cahill G.F.
        • Aoki T.T.
        Alternate fuel utilization by brain.
        in: Passonneau J.V. Hawkins R.A. Lust W.D. Welsh F.A. Cerebral metabolism and neural function. Williams & Wilkins, Baltimore, MD1980
        • Zinn C.
        • Wood M.
        • Williden M.
        • Chatterton S.
        • Maunder E.
        Ketogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes.
        J Int Soc Sports Nutr. 2017; 14: 22
        • Phinney S.D.
        • Horton E.S.
        • Sims E.A.
        • Hanson J.S.
        • Danforth Jr., E.
        • Lagrange B.M.
        Capacity for moderate exercise in obese subjects after adaptation to a hypocaloric, ketogenic diet.
        J Clin Investig. 1980; 66 (https://doi.org/0021-9738/80/11/1152/10): 1152
        • Ackland T.R.
        • Lohman T.G.
        • Sundgot-Borgen J.
        • Maughan R.J.
        • Meyer N.L.
        • Stewart A.D.
        • et al.
        Current status of body composition assessment in sport.
        Sports Med. 2012; 42: 227-249
        • Jackson A.S.
        • Pollack M.L.
        Practical assessment of body composition.
        Phys Sportsmed. 1985; 13: 76-90
        • Gibson A.A.
        • Seimon R.V.
        • Lee C.M.Y.
        • Ayre J.
        • Franklin J.
        • Markovic T.P.
        • et al.
        Do ketogenic diets really suppress appetite? A systematic review and meta-analysis.
        Obes Rev. 2015; 16: 64-76https://doi.org/10.1111/obr.12230
        • Wilson J.M.
        • Lowery R.P.
        • Roberts M.D.
        • Sharp M.H.
        • Joy J.M.
        • Shields K.A.
        • et al.
        The effects of ketogenic dieting on body composition, strength, power, and hormonal profiles in resistance training males.
        J Strength Cond Res. 2017; https://doi.org/10.1519/JSC.0000000000001935
        • Jürimäe J.
        • Tillmann V.
        • Purge P.
        • Jürimäe T.
        Body composition, maximum aerobic performance and inflammatory biomarkers in endurance-trained athletes.
        Clin Physiol Funct Imaging. 2017; 37: 288-292
        • Erlenbusch M.
        • Haub M.
        • Munoz K.
        • MacConnie S.
        • Stillwell B.
        Effect of high-fat or high-carbohydrate diets on endurance exercise: a meta-analysis.
        Int J Sport Nutr Exerc Metab. 2005; 15: 1-14https://doi.org/10.1123/ijsnem.15.1.1
        • Cycling News
        History of the tour de France by numbers.
        (Website)
        • Obradović J.
        • Vukadinović M.
        • Pantović M.
        • Baić M.
        HIIT vs moderate intensity endurance training: impact on aerobic parameters in young adult men.
        Acta Kinesiol. 2016; 10: 35-40
        • Astorino T.A.
        • Edmunds R.M.
        • Clark A.
        • King L.
        • Gallant R.A.
        • Namm S.
        • et al.
        High-intensity interval training increases cardiac output and VO2max.
        Med Sci Sports Exerc. 2017; 49: 265-273https://doi.org/10.1249/MSS.0000000000001099
        • Keating S.E.
        • Johnson N.A.
        • Mielke G.I.
        • Coombes J.S.
        A systematic review and meta-analysis of interval training versus moderate-intensity continuous training on body adiposity.
        Obes Rev. 2017; 18: 943-964https://doi.org/10.1111/obr.12536