Presentation Type
Poster Presentation
Category
STEM (science, technology, engineering, mathematics)
Abstract/Artist Statement
Background: Skeletal muscle recovery is improved with immediate post-exercise carbohydrate feeding. Little is known regarding muscle recovery and performance when feeding is delayed between exercise bouts. The purpose of this study was to examine the effect of varying forms of exogenous carbohydrate on skeletal muscle glycogen recovery and cycling performance with delayed feedings and low skeletal muscle glycogen. Methods: Following 60 minutes of cycling at 65% WMAX 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 fasted (control, CON), then rested for 120 minutes. Participants then cycled for 60 min at 65% WMAX and completed a 19.4 km time trial. Muscle samples were collected pre-feeding, 120 minutes post-feeding, and after cycling for glycogen analyses. Venous blood samples were collected pre-feeding, at minutes 15, 30, 60, and 120 of rest period, and after cycling for 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. Mean power was similar between POT, PAS, and GEL (p>0.05) trials. 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: Delayed carbohydrate intake did not improve skeletal muscle glycogen availability within 120 minutes. Varied pre-exercise exogenous carbohydrate sources effectively improve cycling time trial performance in a glycogen compromised state.
Mentor Name
Ian R Matthews
Exogenous Carbohydrate Form During Low Muscle Glycogen Conditions Has Minimal Impact on Cycling Performance
UC North Ballroom
Background: Skeletal muscle recovery is improved with immediate post-exercise carbohydrate feeding. Little is known regarding muscle recovery and performance when feeding is delayed between exercise bouts. The purpose of this study was to examine the effect of varying forms of exogenous carbohydrate on skeletal muscle glycogen recovery and cycling performance with delayed feedings and low skeletal muscle glycogen. Methods: Following 60 minutes of cycling at 65% WMAX 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 fasted (control, CON), then rested for 120 minutes. Participants then cycled for 60 min at 65% WMAX and completed a 19.4 km time trial. Muscle samples were collected pre-feeding, 120 minutes post-feeding, and after cycling for glycogen analyses. Venous blood samples were collected pre-feeding, at minutes 15, 30, 60, and 120 of rest period, and after cycling for 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. Mean power was similar between POT, PAS, and GEL (p>0.05) trials. 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: Delayed carbohydrate intake did not improve skeletal muscle glycogen availability within 120 minutes. Varied pre-exercise exogenous carbohydrate sources effectively improve cycling time trial performance in a glycogen compromised state.