Eating a meal high in carbohydrates before doing cardio exercise increases how effectively insulin promotes the building of muscle and fat tissue in the body.

When healthy people eat a carb-rich meal, their muscles get more blood flow and their blood vessels relax, even though their body also sends signals to tighten blood vessels—this might help their body absorb sugar from the meal better.

If you eat before working out, your blood sugar and insulin levels spike more during exercise than if you work out on an empty stomach.

Eating carbs while you walk helps your muscles learn to grab sugar from your blood without needing insulin, which over time makes your body better at handling blood sugar.

Eating a meal with 1.5 grams of carbohydrate per kilogram of body weight before running for 90 minutes helps maintain muscle strength and nervous system drive during the run better than eating a meal with 0.8 grams per kilogram, and leads to higher use of carbohydrates for energy and a stronger insulin response.

Adequate dietary protein intake stimulates sufficient insulin secretion to maximize suppression of muscle protein breakdown, rendering additional carbohydrate intake redundant for insulin-mediated anabolic signaling.