| Best Carb Pre Workout: Carbs Before High-Intensity Exercise Does Not Affect Fat Oxidation |
by: Robbie Durand
For years, athletes have been told not to eat high glycemic foods before exercise because it blunts fat mobilization by spiking insulin. Because insulin inhibits fat burning and skeletal muscle fatty acid oxidation and these effects can persist for at least four hours after carbohydrate ingestion. Lower levels of circulating insulin after low-glycemic index pre-exercise meals may promote greater fat oxidation, thus preserving endogenous carbohydrate stores and delaying the onset of fatigue. As anyone that has ever been on a low carbohydrate diet knows that it ‘s hard to perform on a low carb diet but if your training high intensity it may not matter.
| Previous research has reported that high glycemic exercise before moderate intensity exercise has demonstrated increased fat utilization after a low glycemic meal, but the research on high-intensity exercise and glycemic index is lacking. They wanted to know if a high-intensity type exercise protocol was affected by a low or high glycemic index pre-exercise meal. Researchers from Canada reported that a both high and low glycemic index meal before highly intense exercise increased performance compared to going to the gym on an empty stomach, but more interesting there was no effect on insulin, glucose, circulating hormones, or fat oxidation when high-intensity exercise was performed. The take-home message is that if you are performing a moderate intensity exercise, glycemic index can affect fat oxidation but if you are performing high-intensity exercise, glycemic index is not going to impact fat oxidation so don’t feel like you can’t have a sweet potato before exercise is you are going in for a killer high-intensity exercise. |
Little JP, Chilibeck PD, Ciona D, Forbes S, Rees H, Vandenberg A, Zello GA. Effect of low- and high-glycemic-index meals on metabolism and performance during high-intensity, intermittent exercise. Int J Sport Nutr Exerc Metab. 2010 Dec;20(6):447-56.I am text block. Click edit button to change this text. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.
