Basic cycling nutrition.
Three basic calorie-containing components: carbohydrate, fat, protein (and alcohol, depending on who you talk to).
During moderate exercise (~60%of VO2max or less) the body uses ~50% carbohydrates and 50% fat/protein. During intense exercise (>~80% VO2 max), the body uses carbohydrate almost exclusively – the only substrate that can provide energy quickly enough. We store ~500 grams (~2000 calories) of carbohydrate in our bodies as glycogen; when we’ve depleted all the glycogen during intense exercise, we “hit the wall” or “bonk.”
- Carbohydrate = 4 calories/gram
- Fat = 9 calories/gram
- Protein = 4 calories/gram
- Alcohol = 7 calories/gram
We also rely on many other factors, including water and electrolytes, to provide the optimal environment for the chemical reactions of nutrition and muscle contraction to take place. These, too, are depleted during exercise.
By optimizing carbohydrate, water, and electrolyte delivery to muscle, we can provide the right amount of “fuel” for the muscles and the right environment for the muscles to work during intense exercise.
Lower intensity training diet should consist of:
Higher intensity training diet should consist of:
- ~60% carbohydrate (~6 grams per kg of body weight)
- 12-15% protein
- 30% or less fat
Carbohydrates and exercise
- 65-70% carbohydrate (8-10 grams per kg of body weight)
- 12-15% protein
- 20% or less fat
Hydration and exercise
- 1-4 grams of carbohydrate per kg of body weight 1-4 hours before event.
- 30-60 grams of carbohydrate (120-240 calories) per hour during event.
- Start hydrated – lots of fluids in the 24 hours prior to event, avoid excessive alcohol/caffeine.
- 500-750 ml per hour – 5-10 ounces every 15-20 minutes, or one large water bottle per hour.
- If event is greater than one hour, should use an electrolyte-containing energy drink that has
between 6 and 10% carbohydrate (% carbohydrate = grams carbohydrate/ml of fluid x 100).
*Low carbohydrate diets have been shown repeatedly to impair endurance performance.
- The body is primed to replace spent glycogen most efficiently immediately after exercise.
- Having 1 gram of carbohydrate pound of body weight within 30 minutes of finishing exercise and again 2-4 hours later will replenish the majority of glycogen within 24 hours – crucial if training intensely/racing several days in a row.
10 questions that put supplements to the test (from Serious Cycling by Ed Burke, Ph.D.)
- What scientific evidence is available to support the claim?
- Where were the scientific studies conducted?
- By whom? What were the researchers’ and laboratories’ qualifications?
- Do the researchers have a commercial or financial interest in the company?
- Where was the study published? Was it a reputable scientific journal or a magazine?
- Was the study peer reviewed?
- Are there any other studies to support or deny the claims?
- What do recognized experts in the field say about the research?
- Who are the experts? What are their credentials?
- Do the experts have a financial interest in the product?