Your Carbohydrate Intake Calculator for Sport

Background on High Carb

The last few years of sport nutrition has underwent a revolution. Professional riders are going faster than ever and we wanted to know how. Was the Lance Armstrong era of blooding doping back but just undetected? We hope not. There has been groundbreaking changes in nutrition intake regimes. Gone are the days of using a mix of protein and low glycemic index foods as a method of controlling your blood sugar. The goal was to hold back the insulin spike as long as possible and then go to "sugar-town" during the last phase of your event. However, this was hard for many folks to maintain so they instead gambled and played the sugar game hoping their guts would stay in tack!

New products such as Maurten with their Hydrogel technology have revolutionized nutrition. Check out our previous blogs. However, we have found one loophole! How much do you need as we all have different metabolisms? This was the variable that we noticed that needed some fine tuning. It's similar to people using the formula 220-age to determine your maximum heart rate. 90% of the time, this does not work so we do a VO2 test to measure your individuality. The questions that have come up with high carbohydrate nutrition include:

Should larger athletes should consume more than smaller athletes?
How much Maurten do you need to consume based on my VO2?
How much carbohydrate do you consume based off your training zones?

Carbohydrate Utilization by Zone

Over the last two decades, we would provide clients with their metabolic burn rate for each zone. From Zones 1-6, you would see your carbohydrate and fat burning rate in addition to your overall caloric energy expenditure per zone. Many of you have VO2 tests done by TCR over the years, this data will be there. If you never had a VO2 test done....it's time! Below are some examples to review:

Client #1: Male, 58 years, 88kg

Client #2. Male, 57 years, 72kg

Client #3. Female 45 years, 58 kg

Calories per hour:

If you look closely at the calories per hour, all of these numbers are different. Client #2 weighs 10 kg less than client #1 but his caloric burn rate is higher. i.e. 1033 calories per hour vs 922 calories per hour.

Carbohydrate / Fat Ratio:

Client #3 is female, 45 years. Her fat burning rate is significantly better than both men. 76% fat compared to 21 and 28% for Client #1 and #2 respectively. Her fat burning efficiency reduces her need for carbohydrate compared to the men.

As you can see from the above data sets, we all need individual carbohydrate calculators if you want to dial in your nutrition intake during exercise. The recommendation on packages are vague and can be inaccurate. Further, when your fat burning is taken into consideration, this can reduce the need for carbohydrate depending on what zone you are looking at. But, have no fear, we have come up with a calculator!

Carbohydrate Calculator

We have taken the three examples above and calculated the amount of carbohydrate that each person needs based of their unique metabolism. We'll look at Zone 1 through Zone 4 as these are the most used training zones.

Assumptions in determining your Carbohydrate needs:

Men have 699g of glycogen in the muscle and liver based on an 80 kg person.
Women have 499g of glycogen in the muscle and liver based on an 80 kg person.
We can use about 62% of our glycogen stores for exercise. The remainder being utilized for homeostasis and brain function.
Carbohydrate is 4 calories per gram
Fat is 9 calories per gram

As you can see below, a person's metabolism (VO2 score) and their ability to burn fat needs to be considered when calculating your carbohydrate intake.

Client #1:

The overall need for carbohydrate during Zone 3-4 exercise is minimal. This is due to the large amount of available glycogen available due to his body weight (88 kg) and lower metabolic rate.

Client #2:

This is a more typical example of an active cyclist who has a strong VO2 score and lower body weight. He would need to ingest 63g per hour of carbohydrate to maintain pace in a Zone 4 ride.

Client #3:

She has an efficient fat burning metabolism in Zones 1-2 as well as a high VO2 score. She still needs 205 calories per hour of carbohydrate during Zone 4 efforts.

I Want My Numbers!

We'd love to just say, take 80g per hour of carbohydrate as per the package instructions. The new hydrogel formation may allow you to do this without feeling nausea. However, we can recommend exactly what you need based off a VO2 test. We'll measure your burn rate and fat burning in each zone which will give us the data to dial in your nutritional intake. If you have done a test with us and would like your Carbohydrate Calculator numbers, please email us

We are big advocates of individuality with your training. Today, we have many metrics that help us train, rest and overall stay healthy. It's time to take that same approach to your sport nutrition.

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