Master of Science
John M. Kowalchuk
The purpose of this study was to determine the effects of a high carbohydrate (HCHO) and low carbohydrate (LCHO) diet on the adjustment of pulmonary oxygen (O2) uptake ( ) and muscle deoxygenation ([HHb]) during transitions to heavy intensity exercise. Young, healthy, male subjects aged (24+/-3) underwent a 4 day LCHO followed immediately by a 4 day HCHO diet, with each diet preceded by a glycogen depletion protocol. This protocol was designed to alter PDH activity. Subjects completed 3 step transitions to a work rate corresponding to 35% of the difference between their lactate threshold and peak for each condition. On day 3 of the diets gas exchange measurements were collected using mass spectrometry and [HHb] measures were recorded using near-infrared spectroscopy (NIRS). On day 4 of the diets muscle biopsies were taken from the vastus lateralis muscle of the quadriceps muscle group at steady-state baseline exercise (20 W) and at 15 s and 360 s during the transition to heavy exercise. These biopsies were frozen for later analysis. It was found that the dietary manipulation had a significant effect (p0.05) [HHb]. This study posits that PDH plays a crucial role in the adjustment of oxidative metabolism to exercise.
Leckie, John, "The effect of low and high carbohydrate diets on pulmonary oxygen uptake and muscle deoxygenation kinetics during exercise transitions into the heavy-intensity domain" (2013). Electronic Thesis and Dissertation Repository. 1577.