Appetite, gut hormone and energy intake responses to low volume sprint interval and traditional endurance exercise

Sprint interval exercise improves several health markers but the appetite and energy balance response is unknown. This study compared the effects of sprint interval and endurance exercise on appetite, energy intake and gut hormone responses. Twelve healthy males [mean (SD): age 23 (3) years, body mass index 24.2 (2.9) kg m^-2, maximum oxygen uptake 46.3 (10.2) mL kg ^-1 min^-1] completed three 8 h trials [control (CON), endurance exercise (END), sprint interval exercise (SIE)] separated by 1 week. Trials commenced upon completion of a standardised breakfast. Sixty minutes of cycling at 68.1 (4.3) % of maximum oxygen uptake was performed from 1.75-2.75 h in END. Six 30-s Wingate tests were performed from 2.25-2.75 h in SIE. Appetite ratings, acylated ghrelin and peptide YY (PYY) concentrations were measured throughout each trial. Food intake was monitored from buffet meals at 3.5 and 7 h and an overnight food bag. Appetite (P < 0.0005) and acylated ghrelin (P < 0.002) were suppressed during exercise but more so during SIE. Peptide YY increased during exercise but most consistently during END (P < 0.05). Acylated ghrelin was lowest in the afternoon of SIE (P = 0.018) despite elevated appetite (P = 0.052). Exercise energy expenditure was higher in END than that in SIE (P < 0.0005). Energy intake was not different between trials (P > 0.05). Therefore, relative energy intake (energy intake minus the net energy expenditure of exercise) was lower in END than that in CON (15.7 %; P = 0.006) and SIE (11.5 %; P = 0.082). An acute bout of endurance exercise resulted in lower appetite perceptions in the hours after exercise than sprint interval exercise and induced a greater 24 h energy deficit due to higher energy expenditure during exercise.