The Effects of Pre-Exercise Glycemic Index Food on Running Capacity

Abstract

This study examined the effects of pre-exercise food on different glycemic indexes (GI) on exercise metabolism and endurance running capacity. 9 subjects performed 3 exercise trials on different days 15 min after ingesting: lentils, (LGI), potatoes, (HGI), and placebo. Each subject ingested an equal amount of each food (1 g/kg body mass) and ran on a level treadmill for 5 min at 60%, 45 min at 70% and then at 80% of VO_2max until exhaustion. Serum glucose concentrations were higher (P<0.01) 15 min after the HGI trial compared to the LGI and placebo trials. In addition, serum glucose levels were higher (P<0.05) during the LGI trial at the time of exhaustion compared to the HGI and placebo trials. Plasma insulin levels, 15 min after ingestion, were higher (P<0.001) in the HGI trial as compared to the LGI and placebo trials. Exercise time was longer during the LGI trial (P<0.05) compared to the placebo, but the time to exhaustion in the HGI condition did not differ from the placebo (LGI: 90.0±7.9; HGI: 81.8±5; placebo: 73.0±6.4 min). These results suggest that lentils, the LGI food, ingested 15 min before prolonged exercise maintained euglycemia during exercise and enhanced endurance running capacity.

glucose - insulin - metabolism - exhaustion

References

• 1 American College of Sports Medicine .ACSM Fitness Book.. (3rd ed), Champaign, IL: Human Kinetics; 2003: 36-37
• 2 Chryssanthopoulos C, Hennessy L, Williams C. The influence of pre-exercise glucose ingestion on endurance running capacity.  Br J Sports Med. 1994;  28 105-109
• 3 Costill DL, Coyle E, Dalsky D, Evans W, Fink W, Hoopes D. Effects of elevated plasma FFA and insulin on muscle glycogen usage during exercise.  J Appl Physiol. 1977;  43 695-699
• 4 Costill DL, Hargreaves M. Carbohydrate nutrition and fatigue.  Sports Med. 1992;  13 86-92
• 5 DeMarco HM, Sucher KP, Cisar CJ, Butterfield GE. Pre-exercise carbohydrate meals: application of glycemic index.  Med Sci Sports Exerc. 1999;  31 164-170
• 6 Febbraio MA, Stewart KL. CHO feeding before prolonged exercise: effect of glycemic index on muscle glycogenolysis and exercise performance.  J Appl Physiol. 1996;  81 1115-1120
• 7 Febbraio MA, Keenan J, Angus DJ, Campbell SE, Garnham AP. Preexercise carbohydrate ingestion, glucose kinetics, and muscle glycogen use: effect of the glycemic index.  J Appl Physiol. 2000;  89 1845-1851
• 8 Foster C, Costill, Fink WJ. Effects of pre exercise feedings on endurance performance.  Med Sci Sports Exerc. 1979;  11 1-5
• 9 Foster-Powell K, Holt SHA, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002.  Am J Clin Nutr. 2002;  76 5-56
• 10 Frayn KN. Calculation of substrate oxidation rates in vivo from gaseous exchange.  J Appl Physiol. 1983;  55 628-634
• 11 Gleeson M, Maughan RJ, Greenhaff PL. Comparison of the effects of pre-exercise feeding of glucose, glycerol and placebo on endurance and fuel homeostasis in man.  Eur J Appl Physiol. 1986;  55 45-53
• 12 Goodpaster BH, Costill DL, Fink WJ, Trappe TA, Jozsi AC, Starling RD, Trappe SW. The effects of pre-exercise starch ingestion on endurance performance.  Int J Sports Med. 1996;  17 366-372
• 13 Hargreaves M, Costill DL, Katz A, King WJ. Effects of fructose ingestion on muscle glycogen usage during exercise.  Med Sci Sports Exerc. 1985;  17 360-363
• 14 Hargreaves M, Costill DL, Fink WJ, King DS, Fielding RA. Effect of pre-exercise carbohydrate feedings on endurance cycling performance.  Med Sci Sports Exerc. 1987;  19 33-36
• 15 Harriss DJ, Atkinson G. International Journal of Sports Medicine – Ethical Standards in Sport and Exercise Science Research.  Int J Sports Med. 2009;  30 701-702
• 16 Jackson AS, Pollock ML. Generalized equations for predicting body density in men.  Br J Nutr. 1978;  40 497-504
• 17 Jenkins DJA, Thomas DM, Wolever MS, Taylor RH, Barker H, Hashmein Fielden SRD, Baldwin JM, Bowling AC, Newman HC, Jenkins AL, Goff DV. Glycemic index of foods: a physiological basis for carbohydrate exchange.  Am J Clin Nutr. 1981;  34 362-366
• 18 Kirwan JP, Cyr-Campbell D, Campbell WW, Scheiber J, Evans WJ. Effects of moderate and high glycemic index meals on metabolism and exercise performance.  Metabolism. 2001;  50 849-855
• 19 Kirwan JP, O’Gorman DJ, Evans WJ. A moderate glycemic meal before endurance exercise can enhance performance.  J Appl Physiol. 1998;  84 53-59
• 20 Kirwan JP, O’Gorman DJ, Cyr-Campbell D, Campbell WW, Yarasheski KE, Evans WJ. Effects of a moderate glycemic meal on exercise duration and substrate utilization.  Med Sci Sports Exerc. 2001b;  33 1517-1523
• 21 Kuipers H, Fransen EJ, Keizer HA. Pre-exercise ingestion of carbohydrate and transient hypoglycemia during exercise.  Int J Sports Med. 1999;  20 227-231
• 22 Montain SJ, Hopper MK, Coggan AR, Coyle EF. Exercise metabolism at different time intervals after a meal.  J Appl Physiol. 1991;  70 882-888
• 23 Moseley L, Lancaster GI, Jeukendrup AE. Effects of timing of pre-exercise ingestion of carbohydrate on subsequent metabolism and cycling performance.  Eur J Appl Physiol. 2003;  88 453-458
• 24 Sherman WM, Peden MC, Wright DA. Carbohydrate feedings 1 h before exercise improves cycling performance.  Am J Clin Nutr. 1991;  54 866-870
• 25 Sparks MJ, Selig SS, Febbraio MA. Pre-exercise carbohydrate ingestion: effect of the glycemic index on endurance exercise performance.  Med Sci Sports Exerc. 1998;  30 844-849
• 26 Stevenson EJ, Williams C, Mash LA, Phillips B, Nute ML. Influence of high-carbohydrate mixed meals with different glycemic indexes on substrate utilization during subsequent exercise in women.  Am J Clin Nutr. 2006;  84 354-360
• 27 Thomas DE, Brotherhood JR, Brand JC. Carbohydrate feeding before exercise: effect of glycemic index.  Int J Sports Med. 1991;  12 180-186
• 28 Thomas DE, Brotherhood JR, Miller JB. Plasma glucose levels after prolonged strenuous exercise correlate inversely with glycemic response to food consumed before exercise.  Int J Sport Nutr. 1994;  4 361-373
• 29 Tokmakidis SP, Karamanolis IA. Effects of carbohydrate ingestion 15 min before exercise on endurance running capacity.  Appl Physiol Nutr Metab. 2008;  33 441-449
• 30 Tokmakidis SP, Volaklis KA. Pre-exercise glucose ingestion at different time periods and blood glucose concentration during exercise.  Int J Sports Med. 2000;  21 453-457
• 31 Wee SL, Williams C, Gray S, Horabin J. Influence of high and low glycemic index meals on endurance running capacity.  Med Sci Sports Exerc. 1999;  31 393-399
• 32 Wong SH, Lok A, Morris J. Influence of pre-exercise carbohydrate meals on a 21-km run.  Med Sci Sports Exerc. 2003;  35 (Suppl. 1) S298
• 33 Wu CL, Williams C. A low glycemic index meal before exercise improves endurance running capacity in men.  Int J Sport Exerc Metab. 2006;  16 510-527

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