Is a Fat-Supplemented Diet Best for Low-Intensity Exercise?By Kentucky Equine Research Staff · July 3, 2017
This study was designed to determine the effects of fat adaptation on carbohydrate and fat oxidation in conditioned horses during low-intensity exercise.
Five mature Arabians were studied. The study was conducted as a crossover design with two dietary periods, each of 10 weeks' duration: (a) a control (CON) diet, and (b) a fat-supplemented (FAT) diet. The total amount of digestible energy (DE) supplied by the fat in the CON and FAT diets was 7% and 29%, respectively. During each period, the horses completed exercise tests at the beginning of the period (Week 0) and after 5 and 10 weeks on the diet. Tests consisted of 90 minutes of exercise at a speed calculated to elicit 35% VO2max on a treadmill inclined to 3 degrees. Oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory exchange ratio (RER) were measured at 15-minute intervals. For determination of glucose kinetics, a stable isotope ([6-6-d2] glucose) technique was used.
Compared to the CON diet, FAT diet consumption for 5 to 10 weeks was associated with an altered metabolic response to low-intensity exercise, as evidenced by a more than 30% reduction in the production and utilization of glucose; a decrease in RER; a decrease in the estimated rate of whole-body carbohydrate utilization; and an increase in the whole-body rate of lipid oxidation during exercise.
This report of KER's 2002 research was published in Equine Veterinary Journal.
Read the entire research paper, titled Effects of Fat Adaptation on Glucose Kinetics and Substrate Oxidation During Low-Intensity Exercise.