Which macronutrient serves as the primary and most efficient energy source for high-intensity sustained...

Which macronutrient serves as the primary and most efficient energy source for high-intensity sustained exercise?
- Protein
- Carbohydrate
- Saturated fat
- Dietary fiber
Why should pre-workout meals consumed 3 to 4 hours before exercise generally be low in fat and fiber?
- Fat and fiber digest slowly and can cause stomach discomfort
- Fat and fiber immediately deplete muscle glycogen stores
- High fat intake stops protein absorption entirely
- Fiber completely blocks the body from using water