PURPOSE: The effects of glucose-and-fructose (GF) coingestion on cycling time trial (TT) performance and physiological responses to exercise were examined under postprandial conditions. METHODS:Eight trained male cyclists (age, 25 ± 6 yr; height, 180 ± 4 cm; weight, 77 ± 9 kg; V˙O2max, 62 ± 6 mL·kg·min) completed the study. Subjects ingested either an artificially sweetened placebo (PL), a moderate-glucose beverage (MG, 1.03 g·min), a high-glucose beverage (HG, 1.55 g·min), or a GF beverage (1.55 g·min, 2:1 ratio) during approximately 3 h of exercise, including 2 h of constant-load cycling (55% Wmax, 195 ± 17 W), immediately followed by a computer-simulated 30-km TT. Physiological responses (V˙E, V˙O2, RER, HR, blood glucose level, blood lactate level, and RPE) and incidences of gastrointestinal distress were assessed during early (15-20 min), middle (55-60 min), and late exercise (115-120 min) and during the TT. Magnitude-based qualitative inferences were used to evaluate differences between treatments. RESULTS: In comparison with that in PL (52.9 ± 3.7 min), TT performances were faster with GF (50.4 ± 2.2 min, "very likely" benefit), MG (51.1 ± 2.4 min, "likely" benefit), and HG (52.0 ± 3.7 min, "possible" benefit). GF resulted in a "likely" improvement versus HG (3.0%) and an "unclear" effect relative to MG (1.2%). MG was "possibly" beneficial versus HG (1.8%). Few incidences of GI distress were reported in any trials. CONCLUSIONS:GF ingestion seems to enhance performance, relative to PL and HG. However, it is unclear whether GF improves performance versus moderate doses of glucose.
RCT Entities:
PURPOSE: The effects of glucose-and-fructose (GF) coingestion on cycling time trial (TT) performance and physiological responses to exercise were examined under postprandial conditions. METHODS: Eight trained male cyclists (age, 25 ± 6 yr; height, 180 ± 4 cm; weight, 77 ± 9 kg; V˙O2max, 62 ± 6 mL·kg·min) completed the study. Subjects ingested either an artificially sweetened placebo (PL), a moderate-glucose beverage (MG, 1.03 g·min), a high-glucose beverage (HG, 1.55 g·min), or a GF beverage (1.55 g·min, 2:1 ratio) during approximately 3 h of exercise, including 2 h of constant-load cycling (55% Wmax, 195 ± 17 W), immediately followed by a computer-simulated 30-km TT. Physiological responses (V˙E, V˙O2, RER, HR, blood glucose level, blood lactate level, and RPE) and incidences of gastrointestinal distress were assessed during early (15-20 min), middle (55-60 min), and late exercise (115-120 min) and during the TT. Magnitude-based qualitative inferences were used to evaluate differences between treatments. RESULTS: In comparison with that in PL (52.9 ± 3.7 min), TT performances were faster with GF (50.4 ± 2.2 min, "very likely" benefit), MG (51.1 ± 2.4 min, "likely" benefit), and HG (52.0 ± 3.7 min, "possible" benefit). GF resulted in a "likely" improvement versus HG (3.0%) and an "unclear" effect relative to MG (1.2%). MG was "possibly" beneficial versus HG (1.8%). Few incidences of GI distress were reported in any trials. CONCLUSIONS:GF ingestion seems to enhance performance, relative to PL and HG. However, it is unclear whether GF improves performance versus moderate doses of glucose.
Authors: Daniel A Baur; Harrison R Toney; Michael J Saunders; Katherine G Baur; Nicholas D Luden; Christopher J Womack Journal: Eur J Appl Physiol Date: 2019-10-09 Impact factor: 3.078
Authors: Martin Pöchmüller; Lukas Schwingshackl; Paolo C Colombani; Georg Hoffmann Journal: J Int Soc Sports Nutr Date: 2016-07-11 Impact factor: 5.150
Authors: Michael L Newell; Gareth A Wallis; Angus M Hunter; Kevin D Tipton; Stuart D R Galloway Journal: Nutrients Date: 2018-01-03 Impact factor: 5.717
Authors: Andrew C D'Lugos; Nicholas D Luden; Justin M Faller; Jeremy D Akers; Alec I McKenzie; Michael J Saunders Journal: Nutrients Date: 2016-09-07 Impact factor: 5.717
Authors: Nicholas D Luden; Michael J Saunders; Andrew C D'Lugos; Mark W Pataky; Daniel A Baur; Caitlin B Vining; Adam B Schroer Journal: Nutrients Date: 2016-09-20 Impact factor: 5.717