Carbohydrates

Carbohydrates, or carbs, are sugars, starches and fibers in food.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 200.} Glucose circulates in the blood as the main energy source for cells and is stored as glycogen in muscle and liver.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 200.} Carbohydrate provides 4 calories per gram.^{2International Personal Trainer Academy, Certified Personal Trainer Textbook, p. 486.} It isn’t an essential nutrient because the body can make glucose from certain amino acids.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 200.} The NSCA calls it the primary fuel for athletic performance.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 125.}

In practice

• For endurance clients training 90 minutes or more a day, the NSCA recommends about 7 to 10 g/kg per day.^{4Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 126.} Clients doing strength, sprint or skill work can usually get by on 5 to 6 g/kg.^{4Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 126.}
• Those amounts may not fit a calorie deficit: set protein and fat first, then use the remaining calories for carbohydrate.^{4Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 126.}
• Carbohydrate needs follow total energy needs.^{4Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 126.} Beyond roughly 50 to 100 g a day, which prevents ketosis, its role is fuel.^{4Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 126.}
• Many combinations of carbohydrate, protein and fat support training equally well.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 125.} The NSCA recommends adjusting intake to the training program and the client’s past response.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 125.}

How much carbohydrate do the guidelines recommend?

ISSA gives a range of 45 to 65 percent of daily calories for adults.^{5International Sports Sciences Association, Fast Track Study Guide: Nutrition, p. 1.} The NSCA says up to 60 to 70 percent is commonly recommended for physically active clients, but adds that higher-carbohydrate diets don’t suit everyone: some clients gain weight or see higher triglycerides on them.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 125.}