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Randomized Controlled Trial
. 2024 Oct;124(10):3125-3133.
doi: 10.1007/s00421-024-05521-3. Epub 2024 Jun 3.

Effects of food bar chewing duration on the physiologic, metabolic, and perceptual responses to moderate-intensity running

Thomas R Geaney  1 , Zachary A Sievert  2 , J David Branch  1 , Patrick B Wilson  3
Affiliations
Randomized Controlled Trial

Effects of food bar chewing duration on the physiologic, metabolic, and perceptual responses to moderate-intensity running

Thomas R Geaney et al. Eur J Appl Physiol. 2024 Oct.

Abstract

Purpose: Chewing duration can affect food particle size, gastric processing, and postprandial glycemia, but these effects have not been investigated with exercise. This study examined how the chewing duration of a food bar impacts glycemic and metabolic responses, gastrointestinal (GI) symptoms, psychological affect, and performance during endurance running.

Methods: This randomized, unblinded, crossover study had 15 males (35.2 ± 7.4 years, VO2peak: 56.1 ± 5.2 ml/kg/min) attend three laboratory visits. Visit 1 required a VO2peak test, 10 min familiarization run at 60% VO2peak, and familiarization time-to-exhaustion (TTE) test (10 min at 90% VO2peak, followed by TTE at 100% VO2peak). Visits 2 and 3 consisted of a 60 min run at 60% VO2peak, followed by TTE testing. Participants were fed 45 g of a bar (180 kcal, 4 g fat, 33 g carbohydrate, 3 g protein, 1 g fiber) in 9 g servings 30 min before running, and 27 g of bar in 9 g servings at three timepoints during the 60 min run. Participants consumed the servings in 20 (20CHEW) or 40 (40CHEW) masticatory cycles, at 1 chew/second. Outcomes included blood glucose, substrate use, GI symptoms, perceived exertion (RPE), overall feeling, and TTE.

Results: Post-prandial blood glucose, GI symptoms, and RPE increased over time, but there were no significant between-condition or condition-by-time effects. TTE showed no significant between-condition effect (20CHEW: 288 ± 133 s; 40CHEW: 335 ± 299 s; p = 0.240). Overall feeling demonstrated a time-by-condition effect (p = 0.006), suggesting possible better maintenance over time with 40CHEW.

Conclusion: Cumulatively, the results suggest that extended chewing minimally impacts physiology, perceptions, and performance during 60 min moderate-intensity running.

Keywords: Carbohydrate; Exercise; Gut; Metabolism; Sport nutrition.

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Conflict of interest statement

The author declare they have no competing interests.

Figures

Fig. 1
Fig. 1
Overview of the study protocol and measurements
Fig. 2
Fig. 2
Effect of chew duration on blood glucose before, during, and after treadmill exercise. Values are mean ± SE
Fig. 3
Fig. 3
Effect of chew duration on the Feeling Scale before, during, and after treadmill exercise. Values are mean ± SE
Fig. 4
Fig. 4
Effect of chew duration on the time-to-exhaustion performance. Values are mean ± SE
See this image and copyright information in PMC

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