Post-Exercise Appetite and Ad Libitum Energy Intake in Response to High-Intensity Interval Training versus Moderate- or Vigorous-Intensity Continuous Training among Physically Inactive Middle-Aged Adults

High-intensity interval training (HIIT) is considered a time-efficient exercise strategy for weight management. However, data regarding the acute appetite and energy intake responses to HIIT versus continuous training remain inconclusive. This study investigated the ad libitum energy intake and appetite responses to a single session of HIIT versus moderate-intensity continuous training (MICT) and vigorous-intensity continuous training (VICT). Using a randomized crossover design, 11 middle-aged physically inactive men (45.7 +/- 7.4 years, 23.5 +/- 2.1 kg m(-2)) participated in three treadmill trials at 7-day intervals. HIIT comprised 10 1-min periods at 100% VO2max interspersed with 1-min periods of active recovery. MICT comprised a 40-min session at 65% VO2max, while VICT comprised a 20-min session at 80% VO2max. After each trial, the participants consumed an ad libitum buffet meal for which the energy intake was recorded. The participants' perceived appetite was assessed before and after exercise sessions using the Visual Analogue Scale (VAS). No significant differences in post-exercise ad libitum energy intake were observed between trials (HIIT: 645 +/- 262.9 kcal; MICT: 614.7 +/- 271.2 kcal; VICT: 623.1 +/- 249.0 kcal, p > 0.05). Although the perceived appetite responses exhibited a significant main effect of time (p < 0.01), no group differences were observed (p > 0.05). In summary, these findings suggest that the interval or continuous nature of exercise has no significant effect on appetite responses in physically inactive middle-aged adults, at least during the short-term post-exercise period.