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Int J Sports Med 2014; 35(14): 1216-1222
DOI: 10.1055/s-0034-1375635
Nutrition
© Georg Thieme Verlag KG Stuttgart · New York

Self-selecting Fluid Intake while Maintaining High Carbohydrate Availability Does not Impair Half-marathon Performance

M. J. C. Lee
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
K. M. Hammond
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
A. Vasdev
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
K. L. Poole
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
S. G. Impey
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
G. L. Close
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
J. P. Morton
1   Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
› Author Affiliations
Further Information

Publication History



accepted after revision 13 April 2014

Publication Date:
21 August 2014 (online)

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Abstract

We aimed to test the hypothesis that self-selecting fluid intake but maintaining high exogenous CHO availability (60 g/h) does not compromise half-marathon performance. 15 participants completed 3 half-marathons while drinking a 6% CHO solution to guidelines (DRINK) or a non-caloric solution in self-selected volumes when consuming 3×glucose (20 g) gels (G-GEL) or glucose-fructose (13 g glucose+7 g fructose) gels (GF-GEL) per hour. Fluid intake (DRINK: 1 557±182, G-GEL: 473±234, GF-GEL: 404±144 ml) and percent body mass loss (DRINK: − 0.8±0.9, G-GEL: − 2.0±0.6, GF-GEL: −2.3±1.1) were different (P<0.05) between conditions, though race time did not differ (DRINK: 110.6±14.4, G-GEL: 110.3±14.6, GF-GEL: 113.7±12.8 min). In G-GEL, there was a positive correlation (P<0.05) between body mass loss and race time. Plasma glucose was lower (P<0.05) in GF-GEL compared with other conditions, and total CHO oxidation (DRINK: 3.2±0.5, G-GEL: 3.0±0.4, GF-GEL: 2.6±0.4 g/min) was lower (P=0.06) in this trial. Self-selecting fluid intake but maintaining high CHO availability does not impair half-marathon performance. Additionally, consuming glucose-fructose mixtures in sub-optimal amounts reduces plasma glucose and total rates of CHO oxidation.

Key words

glucose - fructose - dehydration - running - endurance
 

  • References

  • 1 Bartlett JD, Louhelainen J, Iqbal Z, Cochran AJ, Gibala MJ, Gregson W, Close GL, Drust B, Morton JP. Reduced carbohydrate availability enhances exercise-induced p53 signalling in human skeletal muscle: implications for mitochondrial biogenesis. Am J Physiol 2013; 304: 450-458
    CrossrefPubMedGoogle Scholar
  • 2 Borg GA. Perceived exertion: a note on ‘‘history’’ and methods. Med Sci Sports 1973; 5: 90-93
    PubMedGoogle Scholar
  • 3 Burke LM, Hawley JA, Wong SH, Jeukendrup AE. Carbohydrates for training and competition. J Sports Sci 2011; 29: 17-27
    CrossrefPubMedGoogle Scholar
  • 4 Carter JM, Jeukendrup AE, Jones DA. The effect of carbohydrate mouth rinse on 1-h cycle time trial performance. Med Sci Sports Exerc 2004; 36: 2107-2111
    PubMedGoogle Scholar
  • 5 Cermak NM, van Loon LJ. The use of Carbohydrates during exercise as an ergogenic aid. Sports Med 2013; 43: 1139-1155
    CrossrefPubMedGoogle Scholar
  • 6 Cheuvront SN, Kenefick RW, Montain SJ, Sawka MN. Mechanisms of aerobic performance impairment with heat stress and dehydration. J Appl Physiol 2010; 109: 1989-1995
    CrossrefPubMedGoogle Scholar
  • 7 Cox GR, Snow RJ, Burke LM. Race-day carbohydrate intakes of elite triathletes contesting Olympic-distance triathlon events. Int J Sport Nutr Exerc Metab 2010; 20: 299-306
    PubMedGoogle Scholar
  • 8 Coyle EF, Coggan AR, Hermmert MK, Ivy JL. Muscle glycogen utilisation during prolonged strenuous exercise when fed carbohydrate. J Appl Physiol 1986; 61: 165-175
    PubMedGoogle Scholar
  • 9 Currell K, Jeukendrup AE. Superior endurance performance with ingestion of multiple transportable carbohydrates. Med Sci Sports Exerc 2008; 40: 275-281
    CrossrefPubMedGoogle Scholar
  • 10 Daries HN, Noakes TD, Dennis SC. Effect of fluid intake volume on 2-h running performances in a 25°C environment. Med Sci Sports Exerc 2000; 32: 1783-1789
    CrossrefPubMedGoogle Scholar
  • 11 Davies CT. Effects of wind assistance and resistance on the forward motion of a runner. J Appl Physiol 1980; 48: 702-709
    PubMedGoogle Scholar
  • 12 Goulet EDB. Effect of exercise-induced dehydration on time-trial exercise performance: a meta-analysis. Br J Sports Med 2011; 45: 1149-1156
    CrossrefPubMedGoogle Scholar
  • 13 Goulet EDB. Effect of exercise-induced dehydration on endurance performance: evaluating the impact of exercise protocols on outcomes using a meta-analytic procedure. Br J Sports Med 2013; 47: 679-686
    CrossrefPubMedGoogle Scholar
  • 14 Harriss DJ, Atkinson G. Update – ethical standards in sport and exercise science research: 2014 update. Int J Sports Med 2013; 34: 1025-1028
    Article in Thieme ConnectPubMedGoogle Scholar
  • 15 Hawley JA, Schabort EJ, Noakes TD, Dennis SC. Carbohydrate-loading and exercise performance. An update. Sports Med 1997; 24: 73-81
    CrossrefPubMedGoogle Scholar
  • 16 Hopkins WG, Hewson DJ. Variability of competitive performance of distance runners. Med Sci Sports Exerc 2001; 33: 1588-1592
    CrossrefPubMedGoogle Scholar
  • 17 Hulston CJ, Wallis GA, Jeukendrup AE. Exogenous CHO oxidation with glucose plus fructose intake during exercise. Med Sci Sports Exerc 2009; 41: 357-363
    PubMedGoogle Scholar
  • 18 Jentjens RL, Jeukendrup AE. High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. Br J Nutr 2005; 93: 483-492
    PubMedGoogle Scholar
  • 19 Jeukendrup AE, Jentjens RL. Oxidation of carbohydrate feedings during prolonged exercise: current thoughts, guidelines and directions for future research. Sports Med 2000; 29: 407-424
    CrossrefPubMedGoogle Scholar
  • 20 Jeukendrup AE, Wallis GA. Measurement of substrate oxidation during exercise by means of gas exchange measurements. Int J Sports Med 2005; 26: S28-S37
    Article in Thieme ConnectPubMedGoogle Scholar
  • 21 Jones AM, Doust JH. A 1% treadmill grade most accurately reflects the energetic cost of outdoor running. J Sports Sci 1996; 14: 321-327
    CrossrefPubMedGoogle Scholar
  • 22 Kao WF, Shyu CL, Yang XW, Hsu TF, Chen JJ, Kao WC, Lee CH. Athletic performance and serial weight changes during 12 and 24 hour ultra-marathons. Clin J Sport Med 2008; 18: 155-158
    CrossrefPubMedGoogle Scholar
  • 23 Merry TL, Ainslie PN, Cotter JD. Effects of aerobic fitness on hypohydration-induced physiological strain and exercise impairment. Acta Physiol 2010; 198: 179-190
    CrossrefPubMedGoogle Scholar
  • 24 Noakes TD, Adams BA, Myburgh KH, Greeff C, Lotz T, Nathan M. The danger of an inadequate water intake during prolonged exercise. A novel concept re-visited. Eur J Appl 1988; 57: 210-219
    PubMedGoogle Scholar
  • 25 Noakes TD. Is drinking to thirst optimum?. Ann Nutr Metab 2010; 57: 9-17
    PubMedGoogle Scholar
  • 26 Nolte HW, Noakes TD, van Vuuren B. Protection of total body water content and absence of hyperthermia despite 2% body mass loss (‘voluntary dehydration’) in soldiers drinking ad libitum during prolonged exercise in cool environmental conditions. Br J Sports Med 2011; 45: 1106-1112
    CrossrefPubMedGoogle Scholar
  • 27 Pfeiffer B, Cotterill A, Grathwohl D, Stellingwerff T, Jeukendrup AE. The effect of carbohydrate gels on gastrointestinal tolerance during a 16-km run. Int J Sport Nutr Exerc Metab 2009; 19: 485-503
    CrossrefPubMedGoogle Scholar
  • 28 Pfeiffer B, Stellingwerff T, Zaltas E, Jeukendrup AE. Carbohydrate oxidation from a carbohydrate gel compared to a drink during exercise. Med Sci Sports Exerc 2010; 42: 2038-2045
    CrossrefPubMedGoogle Scholar
  • 29 Pfeiffer B, Stellingwerff T, Hodgson AB, Randell R, Pottgen K, Res P, Jeukendrup AE. Nutritional intake and gastrointestinal problems during competitive endurance events. Med Sci Sports Exerc 2012; 44: 344-351
    CrossrefPubMedGoogle Scholar
  • 30 Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American college of sports medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc 2007; 39: 377-390
    CrossrefPubMedGoogle Scholar
  • 31 Sharwood KA, Collins M, Goedecke JH, Wilson G, Noakes TD. Weight changes, medical complications, and performance during an Ironman triathlon. Br J Sports Med 2004; 38: 718-724
    CrossrefPubMedGoogle Scholar
  • 32 Tam N, Nolte HW, Noakes TD. Changes in total body water content during running races of 21.1 km and 56 km in athletes drinking ad libitum. Clin J Sport Med 2011; 21: 218-225
    CrossrefPubMedGoogle Scholar
  • 33 Tsintzas K, Williams C, Boobis L, Greenhaff P. Carbohydrate ingestion and glycogen utilization in different muscle fibre types in man. J Physiol 1995; 489: 243-250
    CrossrefPubMedGoogle Scholar
  • 34 Wall BA, Watson G, Peiffer JJ, Abbiss CR, Siegel R, Laursen PB. Current hydration guidelines are erroneous: dehydration does not impair exercise performance in the heat. Br J Sports Med 2013; DOI: 10.1136/bjsports-2013-092417.
    PubMedGoogle Scholar
  • 35 Zouhal H, Groussard C, Minter G, Vincent S, Cretual A, Gratas-Delamarche A, Delamarche P, Noakes TD. Inverse relationship between % weight change and finishing time in 643 42-km marathon runners. Br J Sports Med 2011; 45: 1101-1105
    CrossrefPubMedGoogle Scholar