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

• Published in: European journal of applied physiology 2024-10, Vol.124 (10), p.3125-3133
• Main Authors: Geaney, Thomas R., Sievert, Zachary A., Branch, J. David, Wilson, Patrick B.
• Format: Article
• Language: English
• Subjects: Adult; Biomedical and Life Sciences; Biomedicine; Blood glucose; Blood Glucose - metabolism; Chewing; Cross-Over Studies; Food processing; Human Physiology; Humans; Male; Mastication; Mastication - physiology; Metabolic response; Metabolism; Occupational Medicine/Industrial Medicine; Original; Original Article; Oxygen Consumption - physiology; Physical Exertion - physiology; Running - physiology; Sports Medicine
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-024-05521-3

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, VO 2peak : 56.1 ± 5.2 ml/kg/min) attend three laboratory visits. Visit 1 required a VO 2peak test, 10 min familiarization run at 60% VO 2peak , and familiarization time-to-exhaustion (TTE) test (10 min at 90% VO 2peak , followed by TTE at 100% VO 2peak ). Visits 2 and 3 consisted of a 60 min run at 60% VO 2peak , 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.