Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers

Louise M. Burke, Megan L. Ross, Laura A. Garvican-Lewis, Marijke Welvaert, Ida A. Heikura, Sara G. Forbes, Joanne G. Mirtschin, Louise E. Cato, Nicki Strobel, Avish P. Sharma, John A. Hawley

    Research output: Contribution to journalArticle

    80 Citations (Scopus)

    Abstract

    Key points: Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support. Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole-body fat oxidation during exercise in race walkers over a range of exercise intensities. The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real-life race performance in elite race walkers. In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity. Abstract: We investigated the effects of adaptation to a ketogenic low carbohydrate (CHO), high fat diet (LCHF) during 3 weeks of intensified training on metabolism and performance of world-class endurance athletes. We controlled three isoenergetic diets in elite race walkers: high CHO availability (g kg −1 day −1: 8.6 CHO, 2.1 protein, 1.2 fat) consumed before, during and after training (HCHO, n = 9); identical macronutrient intake, periodised within or between days to alternate between low and high CHO availability (PCHO, n = 10); LCHF (< 50 g day −1 CHO; 78% energy as fat; 2.1 g kg −1 day −1 protein; LCHF, n = 10). Post-intervention, V O2peak during race walking increased in all groups (P < 0.001, 90% CI: 2.55, 5.20%). LCHF was associated with markedly increased rates of whole-body fat oxidation, attaining peak rates of 1.57 ± 0.32 g min −1 during 2 h of walking at ∼80% V O2peak. However, LCHF also increased the oxygen (O 2) cost of race walking at velocities relevant to real-life race performance: O 2 uptake (expressed as a percentage of new V O2peak) at a speed approximating 20 km race pace was reduced in HCHO and PCHO (90% CI: −7.047, −2.55 and −5.18, −0.86, respectively), but was maintained at pre-intervention levels in LCHF. HCHO and PCHO groups improved times for 10 km race walk: 6.6% (90% CI: 4.1, 9.1%) and 5.3% (3.4, 7.2%), with no improvement (−1.6% (−8.5, 5.3%)) for the LCHF group. In contrast to training with diets providing chronic or periodised high-CHO availability, and despite a significant improvement in V O2peak, adaptation to the topical LCHF diet negated performance benefits in elite endurance athletes, in part due to reduced exercise economy.

    Original languageEnglish
    Pages (from-to)2785-2807
    Number of pages23
    JournalThe Journal of Physiology
    Volume595
    Issue number9
    DOIs
    Publication statusPublished - 1 May 2017

    Cite this

    Burke, L. M., Ross, M. L., Garvican-Lewis, L. A., Welvaert, M., Heikura, I. A., Forbes, S. G., ... Hawley, J. A. (2017). Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. The Journal of Physiology, 595(9), 2785-2807. https://doi.org/10.1113/JP273230
    Burke, Louise M. ; Ross, Megan L. ; Garvican-Lewis, Laura A. ; Welvaert, Marijke ; Heikura, Ida A. ; Forbes, Sara G. ; Mirtschin, Joanne G. ; Cato, Louise E. ; Strobel, Nicki ; Sharma, Avish P. ; Hawley, John A. / Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. In: The Journal of Physiology. 2017 ; Vol. 595, No. 9. pp. 2785-2807.
    @article{43513c6f2f654316a18abe9ae62b5008,
    title = "Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers",
    abstract = "Key points: Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support. Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole-body fat oxidation during exercise in race walkers over a range of exercise intensities. The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real-life race performance in elite race walkers. In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity. Abstract: We investigated the effects of adaptation to a ketogenic low carbohydrate (CHO), high fat diet (LCHF) during 3 weeks of intensified training on metabolism and performance of world-class endurance athletes. We controlled three isoenergetic diets in elite race walkers: high CHO availability (g kg −1 day −1: 8.6 CHO, 2.1 protein, 1.2 fat) consumed before, during and after training (HCHO, n = 9); identical macronutrient intake, periodised within or between days to alternate between low and high CHO availability (PCHO, n = 10); LCHF (< 50 g day −1 CHO; 78{\%} energy as fat; 2.1 g kg −1 day −1 protein; LCHF, n = 10). Post-intervention, V O2peak during race walking increased in all groups (P < 0.001, 90{\%} CI: 2.55, 5.20{\%}). LCHF was associated with markedly increased rates of whole-body fat oxidation, attaining peak rates of 1.57 ± 0.32 g min −1 during 2 h of walking at ∼80{\%} V O2peak. However, LCHF also increased the oxygen (O 2) cost of race walking at velocities relevant to real-life race performance: O 2 uptake (expressed as a percentage of new V O2peak) at a speed approximating 20 km race pace was reduced in HCHO and PCHO (90{\%} CI: −7.047, −2.55 and −5.18, −0.86, respectively), but was maintained at pre-intervention levels in LCHF. HCHO and PCHO groups improved times for 10 km race walk: 6.6{\%} (90{\%} CI: 4.1, 9.1{\%}) and 5.3{\%} (3.4, 7.2{\%}), with no improvement (−1.6{\%} (−8.5, 5.3{\%})) for the LCHF group. In contrast to training with diets providing chronic or periodised high-CHO availability, and despite a significant improvement in V O2peak, adaptation to the topical LCHF diet negated performance benefits in elite endurance athletes, in part due to reduced exercise economy.",
    keywords = "athletic performance, ketogenic diet, sports nutrition",
    author = "Burke, {Louise M.} and Ross, {Megan L.} and Garvican-Lewis, {Laura A.} and Marijke Welvaert and Heikura, {Ida A.} and Forbes, {Sara G.} and Mirtschin, {Joanne G.} and Cato, {Louise E.} and Nicki Strobel and Sharma, {Avish P.} and Hawley, {John A.}",
    year = "2017",
    month = "5",
    day = "1",
    doi = "10.1113/JP273230",
    language = "English",
    volume = "595",
    pages = "2785--2807",
    journal = "Journal of Physiology",
    issn = "0022-3751",
    publisher = "Wiley-Blackwell",
    number = "9",

    }

    Burke, LM, Ross, ML, Garvican-Lewis, LA, Welvaert, M, Heikura, IA, Forbes, SG, Mirtschin, JG, Cato, LE, Strobel, N, Sharma, AP & Hawley, JA 2017, 'Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers', The Journal of Physiology, vol. 595, no. 9, pp. 2785-2807. https://doi.org/10.1113/JP273230

    Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. / Burke, Louise M.; Ross, Megan L.; Garvican-Lewis, Laura A.; Welvaert, Marijke; Heikura, Ida A.; Forbes, Sara G.; Mirtschin, Joanne G.; Cato, Louise E.; Strobel, Nicki; Sharma, Avish P.; Hawley, John A.

    In: The Journal of Physiology, Vol. 595, No. 9, 01.05.2017, p. 2785-2807.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers

    AU - Burke, Louise M.

    AU - Ross, Megan L.

    AU - Garvican-Lewis, Laura A.

    AU - Welvaert, Marijke

    AU - Heikura, Ida A.

    AU - Forbes, Sara G.

    AU - Mirtschin, Joanne G.

    AU - Cato, Louise E.

    AU - Strobel, Nicki

    AU - Sharma, Avish P.

    AU - Hawley, John A.

    PY - 2017/5/1

    Y1 - 2017/5/1

    N2 - Key points: Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support. Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole-body fat oxidation during exercise in race walkers over a range of exercise intensities. The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real-life race performance in elite race walkers. In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity. Abstract: We investigated the effects of adaptation to a ketogenic low carbohydrate (CHO), high fat diet (LCHF) during 3 weeks of intensified training on metabolism and performance of world-class endurance athletes. We controlled three isoenergetic diets in elite race walkers: high CHO availability (g kg −1 day −1: 8.6 CHO, 2.1 protein, 1.2 fat) consumed before, during and after training (HCHO, n = 9); identical macronutrient intake, periodised within or between days to alternate between low and high CHO availability (PCHO, n = 10); LCHF (< 50 g day −1 CHO; 78% energy as fat; 2.1 g kg −1 day −1 protein; LCHF, n = 10). Post-intervention, V O2peak during race walking increased in all groups (P < 0.001, 90% CI: 2.55, 5.20%). LCHF was associated with markedly increased rates of whole-body fat oxidation, attaining peak rates of 1.57 ± 0.32 g min −1 during 2 h of walking at ∼80% V O2peak. However, LCHF also increased the oxygen (O 2) cost of race walking at velocities relevant to real-life race performance: O 2 uptake (expressed as a percentage of new V O2peak) at a speed approximating 20 km race pace was reduced in HCHO and PCHO (90% CI: −7.047, −2.55 and −5.18, −0.86, respectively), but was maintained at pre-intervention levels in LCHF. HCHO and PCHO groups improved times for 10 km race walk: 6.6% (90% CI: 4.1, 9.1%) and 5.3% (3.4, 7.2%), with no improvement (−1.6% (−8.5, 5.3%)) for the LCHF group. In contrast to training with diets providing chronic or periodised high-CHO availability, and despite a significant improvement in V O2peak, adaptation to the topical LCHF diet negated performance benefits in elite endurance athletes, in part due to reduced exercise economy.

    AB - Key points: Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support. Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole-body fat oxidation during exercise in race walkers over a range of exercise intensities. The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real-life race performance in elite race walkers. In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity. Abstract: We investigated the effects of adaptation to a ketogenic low carbohydrate (CHO), high fat diet (LCHF) during 3 weeks of intensified training on metabolism and performance of world-class endurance athletes. We controlled three isoenergetic diets in elite race walkers: high CHO availability (g kg −1 day −1: 8.6 CHO, 2.1 protein, 1.2 fat) consumed before, during and after training (HCHO, n = 9); identical macronutrient intake, periodised within or between days to alternate between low and high CHO availability (PCHO, n = 10); LCHF (< 50 g day −1 CHO; 78% energy as fat; 2.1 g kg −1 day −1 protein; LCHF, n = 10). Post-intervention, V O2peak during race walking increased in all groups (P < 0.001, 90% CI: 2.55, 5.20%). LCHF was associated with markedly increased rates of whole-body fat oxidation, attaining peak rates of 1.57 ± 0.32 g min −1 during 2 h of walking at ∼80% V O2peak. However, LCHF also increased the oxygen (O 2) cost of race walking at velocities relevant to real-life race performance: O 2 uptake (expressed as a percentage of new V O2peak) at a speed approximating 20 km race pace was reduced in HCHO and PCHO (90% CI: −7.047, −2.55 and −5.18, −0.86, respectively), but was maintained at pre-intervention levels in LCHF. HCHO and PCHO groups improved times for 10 km race walk: 6.6% (90% CI: 4.1, 9.1%) and 5.3% (3.4, 7.2%), with no improvement (−1.6% (−8.5, 5.3%)) for the LCHF group. In contrast to training with diets providing chronic or periodised high-CHO availability, and despite a significant improvement in V O2peak, adaptation to the topical LCHF diet negated performance benefits in elite endurance athletes, in part due to reduced exercise economy.

    KW - athletic performance

    KW - ketogenic diet

    KW - sports nutrition

    UR - http://www.scopus.com/inward/record.url?scp=85013168187&partnerID=8YFLogxK

    UR - http://www.mendeley.com/research/low-carbohydrate-high-fat-diet-impairs-exercise-economy-negates-performance-benefit-intensified-trai

    U2 - 10.1113/JP273230

    DO - 10.1113/JP273230

    M3 - Article

    VL - 595

    SP - 2785

    EP - 2807

    JO - Journal of Physiology

    JF - Journal of Physiology

    SN - 0022-3751

    IS - 9

    ER -