Saccharide Composition of Carbohydrates Consumed during an Ultra-endurance Triathlon.
OBJECTIVE
Ingesting a mix of glucose and fructose during exercise increases exogenous carbohydrate oxidation while minimizing gastrointestinal (GI) distress. Several studies have suggested that a glucose-to-fructose ratio of 1.2:1 to 1:1 is optimal. No studies have quantified saccharides consumed during a nonsimulated endurance event. The aim of this investigation was to quantify saccharide sources used during an ultra-endurance triathlon and provide a resource for athletes desiring to manipulate the saccharide content of carbohydrate consumed during training and competition.


METHODS
Participant self-report and direct measurement were used to assess foods and beverages consumed during an ultra-endurance (70.3-mile) triathlon. Manufacturer-supplied information, high-performance liquid chromatography, and the US Department of Agriculture Food Database were used to quantify saccharide profiles of foods and beverages. Participants reported GI distress during the run on a 0-10 scale. A subanalysis examined associations between saccharides and GI distress among participants consuming ≥ 50 g·h(-1) of carbohydrate during the swim and cycle.


RESULTS
Fifty-four participants (43 men) used 80 foods and beverages with a unique saccharide profile. Of total carbohydrate, median proportions as glucose, fructose, and sucrose were 64%, 5%, and 10%, and only 7 foods (8.8%) had a glucose-to-fructose ratio of 1.2:1 to 1:1. The median glucose-to-fructose ratio of carbohydrate ingested was 2.9:1 (2.2:1-5.3:1). Twenty participants consumed ≥ 50 g·h(-1) of carbohydrate during the swim and cycle, and significant correlations with incident GI distress at mile 1 of the run were found for glucose (r = 0.480, p = 0.032) and fructose (r = -0.454, p = 0.044).


CONCLUSIONS
The majority of foods and beverages consumed during an ultra-endurance triathlon did not contain an optimal saccharide profile. Furthermore, glucose intake was associated with greater GI distress among participants consuming a high rate of carbohydrate.
a School of Kinesiology, University of Minnesota , Minneapolis , Minnesota.|b Nebraska Athletic Performance Laboratory, University of Nebraska-Lincoln , Lincoln , Nebraska.
Patrick B
PB
Wilson
a School of Kinesiology, University of Minnesota , Minneapolis , Minnesota.
Gregory S
GS
Rhodes
a School of Kinesiology, University of Minnesota , Minneapolis , Minnesota.
Stacy J
SJ
Ingraham
D000293:Adolescent; D000328:Adult; D056352:Athletes; D001628:Beverages / Q000032:analysis; D001642:Bicycling / Q000502:physiology; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000009:adverse effects / Q000032:analysis*; D015444:Exercise / Q000502:physiology; D005504:Food Analysis; D005632:Fructose / Q000032:analysis*; D005767:Gastrointestinal Diseases / Q000209:etiology / Q000517:prevention & control; D005947:Glucose / Q000009:adverse effects / Q000032:analysis*; D006801:Humans; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology; D013177:Sports; D064133:Sports Nutritional Physiological Phenomena; D013550:Swimming / Q000502:physiology
D004040:Dietary Carbohydrates; D005632:Fructose; D005947:Glucose
endurance; exercise; field; gastrointestinal; nutrition