The Effects of a Six-Week Ketogenic Diet on CrossFit Performance Parameters: A Pilot Study

Steven Vitti, Emily Miele, Michael L. Bruneau Jr., Laura Christoph

Abstract


Background: CrossFit is a popular high-intensity functional training method. Despite the importance of muscle glycogen in fueling such high-intensity efforts, research exploring the use of a ketogenic diet in CrossFit practitioners is limited. Objectives: To conduct an experimental trial examining the effects of a 6-week ketogenic diet on CrossFit performance parameters. Methods: Eight men and seven women (N = 15; 30.2 ± 4.11 years) were recruited for this experimental study design and were randomly assigned to either the ketogenic diet (KD; n = 8) or the control group (CON; n = 7) for 6 weeks. Several measures of anaerobic performance were assessed at baseline and after 6 weeks utilizing the following series of standardized exercise tests: timed 500 m row, Wingate Anaerobic Test, and 3-repetition maximum (3-RM) deadlift. Aerobic capacity was also assessed by measuring VO2peak. In addition, body composition was assessed via BodPod. Results: Multiple 2 X 2 mixed factorial analyses of variance were performed for measures of body composition and aerobic and anaerobic performance variables. No significant differences in body composition (p < 0.05), anaerobic performance (p < 0.05), or aerobic performance (p < 0.05) were observed between groups. Conclusion: A 6-week ad libitum KD had no effect on exercise performance or body composition in CrossFit practitioners. Our findings demonstrate that a KD does not impair CrossFit performance, which may be of interest to those considering a KD when participating in CrossFit.

Keywords


CrossFit, Low Carbohydrate, Performance, High-Intensity Exercise, Ketogenic, Body Composition

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References


Aragon, A. A., Schoenfeld, B. J., Wildman, R., Kleiner, S., VanDusseldorp, T., Taylor, L., Earnest, C. P., Arciero, P. J., Wilborn, C., Kalman, D. S., Stout, J. R., Willoughby, D. S., Campbell, B., Arent, S. M., Bannock, L., Smith-Ryan, A. E., & Antonio, J. (2017). International society of sports nutrition position stand: Diets and body composition. Journal of the International Society of Sports Nutrition, 14(1), 16. https://doi.org/10.1186/s12970-017-0174-y

Ashtary-Larky, D., Bagheri, R., Asbaghi, O., Tinsley, G. M., Kooti, W., Abbasnezhad, A., Afrisham, R., & Wong, A. (2021). Effects of resistance training combined with a ketogenic diet on body composition: A systematic review and meta-analysis. Critical Reviews in Food Science and Nutrition, 1–16. https://doi.org/10.1080/10408398.2021.1890689

Bergeron, M. F., Nindl, B. C., Deuster, P. A., Baumgartner, N., Kane, S. F., Kraemer, W. J., Sexauer, L. R., Thompson, W. R., & O’Connor, F. G. (2011). Consortium for Health and Military Performance and American College of Sports Medicine Consensus Paper on Extreme Conditioning Programs in Military Personnel: Current Sports Medicine Reports, 10(6), 383–389. https://doi.org/10.1249/JSR.0b013e318237bf8a

Borg, G. (1998). Borg's perceived exertion and pain scales. Human kinetics.

Bruce, R. A., Kusumi, F., & Hosmer, D. (1973). Maximal oxygen intake and nomographic assessment of functional aerobic impairment in cardiovascular disease. American Heart Journal, 85(4), 546–562. https://doi.org/10.1016/0002-8703(73)90502-4

Burke, L. M. (2021). Ketogenic low‐CHO, high‐fat diet: The future of elite endurance sport? The Journal of Physiology, 599(3), 819–843. https://doi.org/10.1113/JP278928

Burke, L. M., & Hawley, J. A. (2002). Effects of short-term fat adaptation on metabolism and performance of prolonged exercise: Medicine & Science in Sports & Exercise, 34(9), 1492–1498. https://doi.org/10.1097/00005768-200209000-00015

Cholewa, J. M., Newmire, D. E., & Zanchi, N. E. (2019). Carbohydrate restriction: Friend or foe of resistance-based exercise performance? Nutrition, 60, 136–146. https://doi.org/10.1016/j.nut.2018.09.026

Claudino, J. G., Gabbett, T. J., Bourgeois, F., Souza, H. de S., Miranda, R. C., Mezêncio, B., Soncin, R., Cardoso Filho, C. A., Bottaro, M., Hernandez, A. J., Amadio, A. C., & Serrão, J. C. (2018). CrossFit overview: Systematic review and meta-analysis. Sports Medicine - Open, 4(1), 11. https://doi.org/10.1186/s40798-018-0124-5

Cox, P. J., & Clarke, K. (2014). Acute nutritional ketosis: Implications for exercise performance and metabolism. Extreme Physiology & Medicine, 3(1), 17. https://doi.org/10.1186/2046-7648-3-17

Dexheimer, J. D., Schroeder, E. T., Sawyer, B. J., Pettitt, R. W., Aguinaldo, A. L., & Torrence, W. A. (2019). Physiological performance measures as indicators of CrossFit® performance. Sports, 7(4), 93. https://doi.org/10.3390/sports7040093

Durkalec-Michalski, K., Nowaczyk, P. M., Główka, N., Ziobrowska, A., & Podgórski, T. (2021). Is a four-week ketogenic diet an effective nutritional strategy in CrossFit-trained female and male athletes? Nutrients, 13(3), 864. https://doi.org/10.3390/nu13030864

Escobar, K. A., Morales, J., & Vandusseldorp, T. A. (2016). The effect of a moderately low and high carbohydrate intake on Crossfit performance. International Journal of Exercise Science, 9(3), 460–470

Gogojewicz, A., Śliwicka, E., & Durkalec-Michalski, K. (2020). Assessment of dietary intake and nutritional status in CrossFit-trained individuals: A descriptive study. International Journal of Environmental Research and Public Health, 17(13), 4772. https://doi.org/10.3390/ijerph17134772

Gómez-Landero, L. A., & Frías-Menacho, J. M. (2020). Analysis of morphofunctional variables associated with performance in Crossfit ® competitors. Journal of Human Kinetics, 73(1), 83–91. https://doi.org/10.2478/hukin-2019-0134

Greene, D. A., Varley, B. J., Hartwig, T. B., Chapman, P., & Rigney, M. (2018). A low-carbohydrate ketogenic diet reduces body mass without compromising performance in powerlifting and Olympic weightlifting athletes. Journal of Strength and Conditioning Research, 32(12), 3373–3382. https://doi.org/10.1519/JSC.0000000000002904

Gregory, R. M., Hamden, H., Torisky, D. M., & Akers, J. D. (2017). A low-carbohydrate ketogenic diet combined with 6-weeks of CrossFit training improves body composition and performance. International Journal of Sports and Exercise Medicine, 3(2). https://doi.org/10.23937/2469-5718/1510054

Haff, G. G., & Triplett, N. T. (Eds.). (2015). Essentials of strength training and conditioning 4th edition. Human kinetics.

Harvey, K. L., Holcomb, L. E., & Kolwicz, S. C., Jr (2019). Ketogenic diets and exercise performance. Nutrients, 11(10), 2296-2311 https://doi.org/10.3390/nu11102296

Havemann, L., West, S. J., Goedecke, J. H., Macdonald, I. A., St Clair Gibson, A., Noakes, T. D., & Lambert, E. V. (2006). Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. Journal of Applied Physiology, 100(1), 194–202. https://doi.org/10.1152/japplphysiol.00813.2005

Kang, J., Ratamess, N. A., Faigenbaum, A. D., & Bush, J. A. (2020). Ergogenic properties of ketogenic diets in normal-weight individuals: A systematic review. Journal of the American College of Nutrition, 39(7), 665–675. https://doi.org/10.1080/07315724.2020.1725686

Kephart, W., Pledge, C., Roberson, P., Mumford, P., Romero, M., Mobley, C., Martin, J., Young, K., Lowery, R., Wilson, J., Huggins, K., & Roberts, M. (2018). The three-month effects of a ketogenic diet on body composition, blood parameters, and performance metrics in Crossfit trainees: A pilot study. Sports, 6(1), 1-11 https://doi.org/10.3390/sports6010001

Kerksick, C. M., Arent, S., Schoenfeld, B. J., Stout, J. R., Campbell, B., Wilborn, C. D., Taylor, L., Kalman, D., Smith-Ryan, A. E., Kreider, R. B., Willoughby, D., Arciero, P. J., VanDusseldorp, T. A., Ormsbee, M. J., Wildman, R., Greenwood, M., Ziegenfuss, T. N., Aragon, A. A., & Antonio, J. (2017). International society of sports nutrition position stand: Nutrient timing. Journal of the International Society of Sports Nutrition, 14(1), 1-21. https://doi.org/10.1186/s12970-017-0189-4

Lee, H. S., & Lee, J. (2021). Influences of ketogenic diet on body fat percentage, respiratory exchange rate, and total cholesterol in athletes: A systematic review and meta-analysis. International Journal of Environmental Research and Public Health, 18(6), 2912. https://doi.org/10.3390/ijerph18062912

Mangine, G. T., Tankersley, J. E., McDougle, J. M., Velazquez, N., Roberts, M. D., Esmat, T. A., VanDusseldorp, T. A., & Feito, Y. (2020). Predictors of CrossFit open performance. Sports, 8(7), 102. https://doi.org/10.3390/sports8070102

Martínez-Gómez, R., Valenzuela, P. L., Alejo, L. B., Gil-Cabrera, J., Montalvo-Pérez, A., Talavera, E., Lucia, A., Moral-González, S., & Barranco-Gil, D. (2020). Physiological predictors of competition performance in CrossFit athletes. International Journal of Environmental Research and Public Health, 17(10), 3699. https://doi.org/10.3390/ijerph17103699

Maud, P. J., & Shultz, B. B. (1989). Norms for the Wingate anaerobic test with comparison to another similar test. Research Quarterly for Exercise and Sport, 60(2), 144-151.

Murphy, N. E., Carrigan, C. T., & Margolis, L. M. (2021). High-fat ketogenic diets and physical performance: A systematic review. Advances in Nutrition, 12(1), 223–233. https://doi.org/10.1093/advances/nmaa101

Nasser, S., Vialichka, V., Biesiekierska, M., Balcerczyk, A., & Pirola, L. (2020). Effects of ketogenic diet and ketone bodies on the cardiovascular system: Concentration matters. World Journal of Diabetes, 11(12), 584–595. https://doi.org/10.4239/wjd.v11.i12.584

Paoli, A., Mancin, L., Caprio, M., Monti, E., Narici, M. V., Cenci, L., Piccini, F., Pincella, M., Grigoletto, D., & Marcolin, G. (2021). Effects of 30 days of ketogenic diet on body composition, muscle strength, muscle area, metabolism, and performance in semi-professional soccer players. Journal of the International Society of Sports Nutrition, 18(1), 62. https://doi.org/10.1186/s12970-021-00459-9

Rodriguez, N. R., DiMarco, N. M., & Langley, S. (2009). Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the American Dietetic Association, 109(3), 509-527. https://doi.org/10.1016/j.jada.2009.01.005

Sahlin, K. (2014). Muscle energetics during explosive activities and potential effects of nutrition and training. Sports Medicine, 44(S2), 167–173. https://doi.org/10.1007/s40279-014-0256-9

de Souza, R., da Silva, A. G., de Souza, M. F., Souza, L., Roschel, H., da Silva, S. F., & Saunders, B. (2021). A systematic review of CrossFit® workouts and dietary and supplementation interventions to guide nutritional strategies and future research in CrossFit®. International Journal of Sport Nutrition and Exercise Metabolism, 31(2), 187–205. https://doi.org/10.1123/ijs

Stellingwerff, T., Spriet, L. L., Watt, M. J., Kimber, N. E., Hargreaves, M., Hawley, J. A., & Burke, L. M. (2006). Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration. American Journal of Physiology-Endocrinology and Metabolism, 290(2), E380–E388. https://doi.org/10.1152/ajpendo.00268.2005

Thompson, W. R. (2013). Now Trending: Worldwide Survey of Fitness Trends for 2014. ACSM’S Health & Fitness Journal, 17(6), 10–20. https://doi.org/10.1249/FIT.0b013e3182a955e6

Thompson, W. R. (2019). Worldwide survey of fitness trends for 2020. ACSM's Health & Fitness Journal, 23(6), 10-18. https://doi.org/10.1249/FIT.0000000000000526

Urbaniak, G. C., & Plous, S. (2013). Research Randomizer (Version 4.0) [Computer software]. Retrieved on June 22, 2013, from http://www.randomizer.org/

Vigh-Larsen, J. F., Ørtenblad, N., Spriet, L. L., Overgaard, K., & Mohr, M. (2021). Muscle glycogen metabolism and high-intensity exercise performance: A narrative review. Sports Medicine, 51(9), 1855–1874. https://doi.org/10.1007/s40279-021-01475-0




DOI: https://doi.org/10.7575/aiac.ijkss.v.10n.2p.25

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