Effects of high-intensity interval exercise and chocolate milk on glycemic control, appetite, and cognitive performance in 9-13 year-old children

• Published in: Applied physiology, nutrition, and metabolism Vol. 43; no. 4; p. S35
• Main Authors: Prusky, Cydney, Kucab, Michaela, Brett, Neil, Reyes, Ellen, Boateng, Terence, de Zepetnek, Julia O Totosy, Bellissimo, Nick
• Format: Journal Article
• Language: English
• Published: Canadian Science Publishing NRC Research Press 01.01.2018
• Subjects: Appetite; Childrens health; Exercise; Glycemic index; Milk
• ISSN: 1715-5312

Few Canadian children are meeting milk and alternatives or physical activity (PA) guidelines. Chocolate milk has a similar total sugars content to other sugars-sweetened beverages, but has been shown to suppress appetite, attenuate glycemic response, and may favourably affect cognitive performance via its carbohydrate and protein content. High intensity interval exercise (HIIE), a time-efficient PA option, may positively affect glycemic control and appetite and may improve cognitive performance via HIIE-induced cortisol release. The objective of the present study was to determine the separate and combined effects of chocolate milk and HIIE on appetite, glycemic control, and cognitive performance in children. Using a 2x2 within-subject repeated measures design, 20 children (age=11.4±0.34 y) performed HIIE on a cycle ergometer (7 x 60 s sprints, interspersed by 60 s active recovery) or sitting, followed by consumption of 163 kcal chocolate milk or water. Blood glucose via finger prick, subjective average appetite via visual analogue scales and cognitive performance were assessed at baseline, 10, 30, 60 and 90 min post-treatment. Salivary cortisol was assessed at baseline, 10 and 30 min. Cognitive tests evaluated executive functioning, working memory, selective attention, verbal learning and delayed declarative memory. Chocolate milk decreased subjective average appetite compared to HIIE ( -21.6±4.5 mm, p<0.001) and sitting (... -13.6±4.6 mm, p=0.016). Blood glucose increased by 0.37±0.06 mmol/L following chocolate milk consumption compared to water (p<0.001), but was not affected by HIIE (p=0.12). Children recalled more words (... 1.1±0.5 words, p=0.02), had faster reaction time during the n-back test (... -95.6±29.3 ms, p<0.01) and slower reaction time to incongruent stimuli during the Stroop test ( 66.0±24.0 ms, p=0.03) following HIIE compared to sitting. Cortisol was not affected by chocolate milk (p=0.092) or HIIE (p=0.921). While HIIE was insufficient to improve glycemic response or subjective average appetite, it may improve performance in several cognitive domains. HIIE should be promoted as a means to improve cognitive performance in children; future work should investigate potential mechanisms responsible for improved cognitive performance after HIIE. (Supported by: Ryerson University Faculty of Community Services Seed Grant, and the Nutrition and Exercise Testing (NExT) Laboratory.)(Proquest ... denotes non-USASCII text omitted.)