EXOGENOUS CARBOHYDRATE FORM DURING LOW MUSCLE GLYCOGEN CONDITIONS HAS MINIMAL IMPACT ON CYCLING PERFORMANCE

Author

• Ian R. Matthews, University of Montana, MissoulaFollow
• Alejandro M. Rosales, University of Montana, MissoulaFollow
• Josey K. Walker, University of Montana, MissoulaFollow
• Noah B. Wilfong, University of Montana, MissoulaFollow
• Rachel E. Perez, University of Montana, MissoulaFollow
• Brent C. Ruby, University of Montana, MissoulaFollow
• Dustin Slivka, University of Montana, MissoulaFollow

Year of Award

2026

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Integrative Physiology (Exercise Science option)

Department or School/College

Integrative Physiology and Athletic Training

Committee Chair

Dustin R. Slivka

Commitee Members

Brent C. Ruby, Brian J. Loyd

Keywords

energy gel, potato, pasta, fasting, sport nutrition, time trial

Subject Categories

Exercise Physiology | Exercise Science | Systems and Integrative Physiology

Abstract

Background: Skeletal muscle recovery is improved with immediate post-exercise carbohydrate feeding. Little is known regarding muscle recovery and performance when feeding is delayed. The purpose was to examine the effect of varying exogenous carbohydrates on cycling performance with delayed feedings and low skeletal muscle glycogen. Methods: Following 60 minutes of cycling and an overnight fast (12.1±0.4 hours), participants consumed 2.10±0.13 g·kg^-1 bodyweight carbohydrate of one of the following: whole potatoes (POT), cooked pasta (PAS), energy gel (GEL) or remained unfed (control, CON), then rested for 120 minutes. Participants then cycled for 60 min at 65% W_max and completed a 19.4 km time trial. Muscle and blood samples were collected pre-feeding, 120 minutes post-feeding, and after cycling for glycogen, glucose, and insulin analyses. Results: Time trial mean power output was higher in PAS (213±56W, p=0.006) and GEL (209±71W, p=0.011) compared to CON (179±68W), but POT (196±51W, p=0.199) was not different from CON. Power was similar between POT, PAS, and GEL (p>0.05). Time trial finish time trended towards significance (p=0.088) with carbohydrate trials averaging 3 minutes faster than CON. Muscle glycogen was similar between trials (p=0.446) and did not change due to feeding (pre-feeding: 44±21 mmol·kg^-1, post-feeding: 47±23 mmol·kg^-1, p=0.120). Glycogen declined after cycling for 60 min (26±16 mmol·kg^-1, p< 0.001) compared to pre-feeding and post-feeding samples. Glucose and insulin were elevated in carbohydrate trials over CON 0-30 minutes post-feeding (p< 0.05). Conclusions: Varied pre-exercise exogenous carbohydrate sources effectively improve cycling time trial performance in a glycogen compromised state.

Recommended Citation

Matthews, Ian R.; Rosales, Alejandro M.; Walker, Josey K.; Wilfong, Noah B.; Perez, Rachel E.; Ruby, Brent C.; and Slivka, Dustin, "EXOGENOUS CARBOHYDRATE FORM DURING LOW MUSCLE GLYCOGEN CONDITIONS HAS MINIMAL IMPACT ON CYCLING PERFORMANCE" (2026). Graduate Student Theses, Dissertations, & Professional Papers. 12615.
https://scholarworks.umt.edu/etd/12615