Date of Award
Master of Science in Education (MSEd)
Human Movement Sciences
David Swain (Chair)
The purpose of this study was to investigate immediate and delayed metabolic and dietary responses to a single bout of cycling high-intensity interval exercise (HIIE) performed in the fasted and fed state. Baseline values of 11 subjects (6 female, 5 male) for resting energy expenditure (REE), respiratory exchange ratio (RER), resting VO2, VO2max and appetite score (VAS) were measured on the first visit. Energy balance (EB) was determined using diet tracking and activity energy expenditure (paEE). Trials followed a day at net energy balance and began in a fasted state. A 240-kcal energy bar was consumed prior to (FED) or after (FST) a high-intensity interval exercise (HIIE) bout. Post-exercise VO2 was recorded for one hour (60 of 70 minutes) immediately following HIIE. Metabolic variables were measured before and 12 hours after exercise. Energy intake was not different between conditions the day before trials (mean ± SD: 2060 ± 613 kcal FED, 2154 ± 666 kcal FST) or the 12 hours after exercise (1695 ± 484 kcal FED, 1892 ± 822 kcal FST). Post-exercise VAS was greater than 12 hours later (p < 0.01). Post-exercise EE (97.0 ± 15.2 kcal.hr-1 FED, 89.9 ± 17.2 kcal.hr-1 FST) was elevated from pre-exercise (70.8 ± 10.7 kcal.hr-1 FED; p < 0.01, 67.9 ± 10.2 kcal.hr-1 FST; p = 0.01). Post-exercise VO2 (272.2 ± 25.8 mL.hr-1.kg-1 FED, 254.2 ± 33.5 mL.hr-1.kg-1 FST) was elevated from pre-exercise (203.4 ± 25.4 mL.hr-1.kg-1 FED; p < 0.01, 195.6 ± 12.5 mL.hr-1.kg-1 FST; p < 0.01). Excess EE (26.2 ± 10.6 kcal FED, 22.0 ± 11.8 kcal FST) and EPOC (68.8 ± 28.6 mL.kg-1 FED, 58.6 ± 32.5 mL.kg-1 FST) over 60 minutes did not differ between conditions. Appetite was blunted in the hours following HIIE supporting the transient effect of exercise on appetite. Excess EE and EPOC did occur in the hour following exercise. However, whether a 240-kcal meal replacement bar was consumed immediately before or shortly after morning HIIE did not significantly impact resulting EPOC, RER, EI or appetite.
Perez, William J..
"The Effect of Fasted vs Fed High-Intensity Interval Exercise on Metabolism and Diet"
(2016). Master of Science in Education (MSEd), Thesis, Human Movement Sciences, Old Dominion University, DOI: 10.25777/tx7d-3b11