Abstract

Carbohydrate (CHO) loading is believed to be an ergogenic dietary asset for aerobic performance by maximizing CHO oxidation and to combat glycogen depletion within the working muscle cells. However, evidence-based research has displayed that an increase in fat metabolism, subsequently lower CHO oxidation, may provide sufficient energy during submaximal and maximal exertion through beta oxidation.For this reason, active volunteers were recruited to undergo a double-blind study to determine if an acute carbohydrate loading dietary supplement was effective in enhancing performance on a maximal oxygen uptake (VO₂ ) test. Eleven college aged (22.09±1.3) students (male n=8, female n=3) participated in this double-blind randomized study. Subjects consumed either a CHO (1g/kg body weight) or placebo supplement followed by a 12 hour fast. Following this fast, first testing session consisted of a seven-point skin caliper for body composition (% body fat), fasting blood glucose as measured by point of care finger stick method using Abbott Precision blood glucose meter (mg/dL), and a VO₂ max test (mL/kg/min) measured by a modified Tread Sport Treadmill Protocol. Prior to the second test date, the subject consumed either CHO supplement or placebo, followed by 12 hour fast. Second test day consisted of fasting blood glucose, and VO2 max test. Protocols were matched for the second bout of testing.A paired samples t-test (SPSS v.26) was conducted to determine significance (p≤0.05) on each of the four variables: VO2 max, fasting blood glucose (GLU), anaerobic threshold (AT), and respiratory quotient (RQ). No significant differences were found when comparing groups on all variables (VO₂ p=0.923,GLU p=0.099, AT p=0.641, RQ p=0.372). Acute CHO loading has no significant impact on performance variables as defined by AT, RQ, and VO₂ max.

Keywords

carbohydrate loading, VO2 max, fat oxidation, anaerobic threshold, sports performance, metabolic flexibility