Non-invasive techniques for assessing carbohydrate flux. II: Measurement of deposition using 13C-glucose

A non-invasive method for studying the dynamics of post-exercise carbohydrate storage by means of whole-body calorimetry and 13 CO 2 breath tests is described. Seven untrained glycogen-depleted subjects were offered naturally 13 C-labelled high carbohydrate meals (97% by energy) at 30 min intervals for 5 h and asked to consume as much as possible. Mean intake averaged 757±211 (SD) g. Exogenous carbohydrate oxidation over 16 h calculated from gas exchange and isotope ratio measurements averaged 161±45 g, and endogenous carbohydrate oxidation averaged 31±25 g