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.