Research Repository

Effect of graded fructose coingestion with maltodextrin on exogenous 14C-fructose and 13C-glucose oxidation efficiency and high-intensity cycling performance

Rowlands, David and Thorburn, Megan and Thorp, Rhys and Broadbent, Suzanne and Shi, Xiaocai (2008) Effect of graded fructose coingestion with maltodextrin on exogenous 14C-fructose and 13C-glucose oxidation efficiency and high-intensity cycling performance. Journal of Applied Physiology, 104 (6). pp. 1709-1719. ISSN 8750-7587

Full text for this resource is not available from the Research Repository.

Abstract

The ingestion of solutions containing carbohydrates with different intestinal transport mechanisms (e.g., fructose and glucose) produce greater carbohydrate and water absorption compared with singlecarbohydrate solutions. However, the fructose-ingestion rate that results in the most efficient use of exogenous carbohydrate when glucose is ingested below absorption-oxidation saturation rates is unknown. Ten cyclists rode 2 h at 50% of peak power then performed 10 maximal sprints while ingesting solutions containing 13C-maltodextrin at 0.6 g/min combined with 14C-fructose at 0.0 (No-Fructose), 0.3 (Low-Fructose), 0.5 (Medium-Fructose), or 0.7 (High-Fructose) g/min, giving fructose:maltodextrin ratios of 0.5, 0. 8, and 1.2. Mean (percent coefficient of variation) exogenous-fructose oxidation rates during the 2-h rides were 0.18 (19), 0.27 (27), 0.36 (27) g/min in Low-Fructose, Medium-Fructose, and High-Fructose, respectively, with oxidation efficiencies (�oxidation/ingestion rate) of 62–52%. Exogenous-glucose oxidation was highest in Medium-Fructose at 0.57 (28) g/min (98% efficiency) compared with 0.54 (28), 0.48 (29), and 0.49 (19) in Low-Fructose, High-Fructose, No-Fructose, respectively; relative to No-Fructose, only the substantial 16% increase (95% confidence limits �16%) in Medium-Fructose was clear. Total exogenous- carbohydrate oxidation was highest in Medium-Fructose at 0.84 (26) g/min. Although the effect of fructose quantity on overall sprint power was unclear, the metabolic responses were associated with lower perceptions of muscle tiredness and physical exertion, and attenuated fatigue (power slope) in the Medium-Fructose and High- Fructose conditions. With the present solutions, low-medium fructose- ingestion rates produced the most efficient use of exogenous carbohydrate, but fatigue and the perception of exercise stress and nausea are reduced with moderate-high fructose doses.

Item Type: Article
Uncontrolled Keywords: ResPubID16823, dose response, dual-tracer method, substrate metabolism, gastrointestinal distress, fatigue
Subjects: FOR Classification > 1106 Human Movement and Sports Science
Faculty/School/Research Centre/Department > School of Sport and Exercise Science
Related URLs:
Depositing User: VUIR
Date Deposited: 15 Sep 2011 05:32
Last Modified: 15 Sep 2011 05:32
URI: http://vuir.vu.edu.au/id/eprint/3918
DOI: 10.1152/japplphysiol.00878.2007
ePrint Statistics: View download statistics for this item
Citations in Scopus: 24 - View on Scopus

Repository staff only

View Item View Item

Search Google Scholar