LAST UPDATED: March 24, 2023

​Impact of carbohydrate consumption on performance

Performance benefits of carbohydrates:

  • Provide a quick start
  • Deliver endurance fuel
  • Increase alertness
  • Fuel short bursts of energy
  • Ensure quick recovery
  • Provide energy that lets you do the work to build muscle size and strength

Carbohydrate is the ultra–premium energy fuel and is vital for endurance and strength activities. Foods high in carbohydrates include pasta, bread, vegetables, fruit, legumes (like beans, peas, lentils, and peanuts), and even milk and yogurt. When you digest them, they become blood sugar. Blood sugar is then converted into a substance called glycogen, which is stored in your muscles and liver as your body’s premium source of available energy.

Glycogen is a high-performance fuel, but it burns quickly—and your body can’t store that much of it. After about 90 minutes of continuous exercise or during a day of intermittent strenuous physical activity, your muscle glycogen gets low. High heat and high intensity activity also increase the rate of glycogen depletion.

On the other hand, training increases your body’s ability to store glycogen. As you get into better shape, your muscles can store more glycogen to keep you going longer. When you are fit, your muscles are also better at replacing glycogen right after exercise. That is one reason why when you are in better shape, you don’t seem as tired as you did when you began training.

Your body makes glycogen from unprocessed carbohydrate–rich sources. Good sources of unprocessed carbohydrates include grains (rice, barley, whole grain bread, pasta, cereal), legumes, vegetables (spinach, zucchini, broccoli), and fruits (blueberries, bananas, and cantaloupe).

Performance problems from eating too few carbohydrates:

  • Lack of endurance: you might have to stop and rest before an activity ends
  • Decreased muscular strength
  • Harder to recover: no energy left for later in the day or for the next day
  • Slower speed: you must slow down to make it to the end
  • Reduced concentration: your brain gets fuzzy
  • Reduced coordination
  • Chronic fatigue
  • Lack of motivation
  • General fatigue and increased irritability

Consuming enough carbohydrate each day is necessary to meet the demands of physical training and refill muscle and liver glycogen supplies in between training sessions. Use the chart below to determine how many grams of carbohydrate you need each day.

How much carbohydrate do I need?

Carbohydrate needs per activity level
Activity Level Recommended Carbohydrate Intake, g/kg Recommended Carbohydrate Intake,
Low to moderate-intensity training activity, ≈ 30 min/day 3–5 1.36–2.27
Moderate-intensity training activity, ≈ 60 min/day 5–7 2.27–3.18
Moderate to high-intensity endurance training, 1–3 hrs./day 6–10 2.72–4.55
Moderate to high-intensity training, 4–5 hrs./day 8–12 3.64–5.45

Carbohydrate calculator

Enter the following information into the calculator to compute your daily carbohydrate needs.

Step 1: Choose your Daily Activity Level from the drop-down list.

Step 2: Enter your Weight in pounds.

Step 3: Your results for Carbohydrate Range and Daily Carbohydrate Needs will be displayed on the corresponding lines.


My Carbohydrate Needs Calculator

Daily Activity Level:
My Weight (in lbs.):
Carbohydrate Range (based on activity): _________ to _________
Daily Carbohydrate Needs (grams): _________ to _________

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