High versus low glycemic index 3-h recovery diets following glycogen-depleting exercise has no effect on subsequent 5-km cycling time trial performance

L J S Brown, A W Midgley, R V Vince, L A Madden, Lars McNaughton

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6 Citations (Scopus)

Abstract

Objectives Some athletes train/compete multiple times in a single day and rapid restoration of muscle and hepatic glycogen stores is therefore important for athletic performance. Design Randomised, counterbalanced, crossover, single blinded study investigated the effects of low/high glycaemic index (GI) meals on the physiological responses to a 3-h recovery period and subsequent 5-km cycling time trial (TT). Methods Seven male cyclists completed glycogen-depleting exercise followed by a 3-h recovery period, when participants consumed either a high or low GI meal providing 2 g kg−1 BM of carbohydrate. Participants then performed a 5-km cycling TT. Blood samples were analysed for glucose insulin, free fatty acid (FFA) and triglyceride. Results There was no significant difference between the median (IQR) cycling TT time of 8.5 (3.0) min in the LGI condition and 8.4 (1.8) min in the HGI condition (p = 0.45). Serum insulin was significantly higher in the HGI condition throughout the 3-h recovery period (p = 0.025), FFA concentrations were higher in the HGI condition only at 30 min into recovery (p = 0.008). The respiratory exchange ratio (p = 0.028) and carbohydrate oxidation rate (p = 0.015) increased over time in the HGI condition, whereas the rate of fat oxidation demonstrated the opposite response (p = 0.001). No significant differences between conditions were observed for any physiological variables at the end of the 5-km TT. Conclusions Although the GI of the two meals indicated important metabolic differences during the recovery period, there was no evidence suggesting these differences influenced subsequent 5-km TT performance.
Original languageEnglish
Pages (from-to)450-454
JournalJournal of Science and Medicine in Sport
Volume16
Issue number5
DOIs
Publication statusPublished - Sep 2013

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Glycemic Index
Glycogen
Exercise
Diet
Meals
Nonesterified Fatty Acids
Carbohydrates
Insulin
Athletic Performance
Liver Glycogen
Athletes
Triglycerides
Fats
Glucose
Muscles

Keywords

  • Athletic performance
  • Carbohydrate
  • Insulin
  • Sports nutrition

Cite this

@article{2fc96ba2c7da4329a29ae085a0f517d8,
title = "High versus low glycemic index 3-h recovery diets following glycogen-depleting exercise has no effect on subsequent 5-km cycling time trial performance",
abstract = "Objectives Some athletes train/compete multiple times in a single day and rapid restoration of muscle and hepatic glycogen stores is therefore important for athletic performance. Design Randomised, counterbalanced, crossover, single blinded study investigated the effects of low/high glycaemic index (GI) meals on the physiological responses to a 3-h recovery period and subsequent 5-km cycling time trial (TT). Methods Seven male cyclists completed glycogen-depleting exercise followed by a 3-h recovery period, when participants consumed either a high or low GI meal providing 2 g kg−1 BM of carbohydrate. Participants then performed a 5-km cycling TT. Blood samples were analysed for glucose insulin, free fatty acid (FFA) and triglyceride. Results There was no significant difference between the median (IQR) cycling TT time of 8.5 (3.0) min in the LGI condition and 8.4 (1.8) min in the HGI condition (p = 0.45). Serum insulin was significantly higher in the HGI condition throughout the 3-h recovery period (p = 0.025), FFA concentrations were higher in the HGI condition only at 30 min into recovery (p = 0.008). The respiratory exchange ratio (p = 0.028) and carbohydrate oxidation rate (p = 0.015) increased over time in the HGI condition, whereas the rate of fat oxidation demonstrated the opposite response (p = 0.001). No significant differences between conditions were observed for any physiological variables at the end of the 5-km TT. Conclusions Although the GI of the two meals indicated important metabolic differences during the recovery period, there was no evidence suggesting these differences influenced subsequent 5-km TT performance.",
keywords = "Athletic performance, Carbohydrate, Insulin, Sports nutrition",
author = "Brown, {L J S} and Midgley, {A W} and Vince, {R V} and Madden, {L A} and Lars McNaughton",
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TY - JOUR

T1 - High versus low glycemic index 3-h recovery diets following glycogen-depleting exercise has no effect on subsequent 5-km cycling time trial performance

AU - Brown, L J S

AU - Midgley, A W

AU - Vince, R V

AU - Madden, L A

AU - McNaughton, Lars

PY - 2013/9

Y1 - 2013/9

N2 - Objectives Some athletes train/compete multiple times in a single day and rapid restoration of muscle and hepatic glycogen stores is therefore important for athletic performance. Design Randomised, counterbalanced, crossover, single blinded study investigated the effects of low/high glycaemic index (GI) meals on the physiological responses to a 3-h recovery period and subsequent 5-km cycling time trial (TT). Methods Seven male cyclists completed glycogen-depleting exercise followed by a 3-h recovery period, when participants consumed either a high or low GI meal providing 2 g kg−1 BM of carbohydrate. Participants then performed a 5-km cycling TT. Blood samples were analysed for glucose insulin, free fatty acid (FFA) and triglyceride. Results There was no significant difference between the median (IQR) cycling TT time of 8.5 (3.0) min in the LGI condition and 8.4 (1.8) min in the HGI condition (p = 0.45). Serum insulin was significantly higher in the HGI condition throughout the 3-h recovery period (p = 0.025), FFA concentrations were higher in the HGI condition only at 30 min into recovery (p = 0.008). The respiratory exchange ratio (p = 0.028) and carbohydrate oxidation rate (p = 0.015) increased over time in the HGI condition, whereas the rate of fat oxidation demonstrated the opposite response (p = 0.001). No significant differences between conditions were observed for any physiological variables at the end of the 5-km TT. Conclusions Although the GI of the two meals indicated important metabolic differences during the recovery period, there was no evidence suggesting these differences influenced subsequent 5-km TT performance.

AB - Objectives Some athletes train/compete multiple times in a single day and rapid restoration of muscle and hepatic glycogen stores is therefore important for athletic performance. Design Randomised, counterbalanced, crossover, single blinded study investigated the effects of low/high glycaemic index (GI) meals on the physiological responses to a 3-h recovery period and subsequent 5-km cycling time trial (TT). Methods Seven male cyclists completed glycogen-depleting exercise followed by a 3-h recovery period, when participants consumed either a high or low GI meal providing 2 g kg−1 BM of carbohydrate. Participants then performed a 5-km cycling TT. Blood samples were analysed for glucose insulin, free fatty acid (FFA) and triglyceride. Results There was no significant difference between the median (IQR) cycling TT time of 8.5 (3.0) min in the LGI condition and 8.4 (1.8) min in the HGI condition (p = 0.45). Serum insulin was significantly higher in the HGI condition throughout the 3-h recovery period (p = 0.025), FFA concentrations were higher in the HGI condition only at 30 min into recovery (p = 0.008). The respiratory exchange ratio (p = 0.028) and carbohydrate oxidation rate (p = 0.015) increased over time in the HGI condition, whereas the rate of fat oxidation demonstrated the opposite response (p = 0.001). No significant differences between conditions were observed for any physiological variables at the end of the 5-km TT. Conclusions Although the GI of the two meals indicated important metabolic differences during the recovery period, there was no evidence suggesting these differences influenced subsequent 5-km TT performance.

KW - Athletic performance

KW - Carbohydrate

KW - Insulin

KW - Sports nutrition

U2 - 10.1016/j.jsams.2012.10.006

DO - 10.1016/j.jsams.2012.10.006

M3 - Article

VL - 16

SP - 450

EP - 454

JO - Journal of Science and Medicine in Sport

JF - Journal of Science and Medicine in Sport

SN - 1440-2440

IS - 5

ER -