Michaela Kucab, Nick Bellissimo, Cydney Prusky, Neil R Brett, Julia O Totosy de Zepetnek
BACKGROUND/OBJECTIVES: To investigate the separate and combined effects of a single session of high intensity interval training (HIIT) and chocolate milk on appetite and cognitive performance in youth aged 9-13 years. Blood glucose, salivary cortisol, and subjective emotions were measured to evaluate potential underlying mechanisms contributing to changes in appetite and cognitive performance.
SUBJECTS/METHODS: Using a 2 × 2 repeated measures design, 20 youth (n = 12 girls and n = 8 boys; age = 11.4 ± 0.3 years) performed HIIT on a cycle ergometer (7 × 60 s bouts, interspersed by 60 s active recovery) or sitting, followed by consumption of 163 kcal chocolate milk or water. Capillary blood glucose, salivary cortisol, cognitive performance, and subjective appetite and emotions were assessed at baseline and at several time points post-treatment.
RESULTS: Subjective appetite decreased from baseline following chocolate milk consumption compared water (p = 0.04), and increased from baseline after HIIT compared to sitting (p = 0.01). Participants recalled more words during a short-term memory task and had faster reaction times during an attention task following HIIT compared to sitting (Δ = 1.1 ± 0.02 words, p = 0.03; and Δ = 117.9 ± 23.1 ms, p = 0.01, respectively). Blood glucose increased from baseline following chocolate milk consumption compared to water (at 10 min: Δ = 1.0 ± 0.33 vs. Δ = 0.29 ± 0.060 mmol/L; p < 0.0001).
CONCLUSIONS: Our findings that HIIT may have a positive effect on aspects of cognitive performance suggest that youth should engage in HIIT-like exercise during recesses and lunch at school to attenuate declines in cognitive performance throughout the day. Registered at https://clinicaltrials.gov (NCT03305107).