Fructose is as good a fuel as glucose for exercise in normal subjects.
50 g fructose and 50 g glucose loads, naturally 13C labelled, were orally administered in random order to six healthy subjects submitted to 90 mn exercise at VO2 max/2 on a treadmill. 13CO2/12CO2 variations in the expired air were followed before and after exercise for a total of 240 min. On the whole, fructose appeared to be as good a fuel as glucose during exercise even if slight but significant differences in kinetics were observed: the delta 13C peak values at 90 min were significantly lower with fructose. Between 90 and 240 min, delta 13C remained higher but not significantly with 13C-fructose than with 13C-glucose. During exercise, plasma glucose and insulin levels were significantly lower (p less than 0.05 and p less than 0.01) after fructose than after glucose. We conclude that fructose can be readily used during exercise by healthy subjects.
Slama
G
G
Department of diabetes, Hôtel-Dieu Hospital, Paris, France.
Boillot
J
J
Hellal
I
I
Darmaun
D
D
Rizkalla
S W
SW
Orvoen-Frija
E
E
Dore
M F
MF
Guille
G
G
Fretault
J
J
Coursaget
J
J
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002247:Carbon Isotopes; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004734:Energy Metabolism; D005260:Female; D005632:Fructose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D005082:Physical Exertion; D012016:Reference Values
D001786:Blood Glucose; D002247:Carbon Isotopes; D004040:Dietary Carbohydrates; D007328:Insulin; D005632:Fructose; D005947:Glucose