Supposedly healthy: These 7 nutritional mistakes could slow you down when running

High-fiber whole-grain cereals might seem like a smart choice to start the day at first glance. However, as pre-run food, they're a recipe for gastrointestinal problems. Fiber takes longer to digest and can cause bloating, so a sudden urge to go to the bathroom during a run isn't out of the question.

Better choice: Enjoy high-fiber cereal at least three hours before your run. If you want to eat closer to the start time, switch to more easily digestible foods. A small bowl of instant oatmeal or white bread with nut butter and a banana provides quick energy without causing stomach upset.

2. Energy Granola

Granola is often advertised as an energy boost, but it's not always a good fit for running. It's high in calories and often contains added sugar and oils. Even the "healthy" versions can cause a sugar spike in large quantities.

Better choice : Use the granola sparingly as a topping for Greek yogurt or cottage cheese and combine it with fresh fruit.