My client Vince recently wrote me, “This was not my best ride. Maybe my worst. A few 18-20 percent grades that I walked. Lots of 10-15 percent hills. I was struggling at 9 mph for a time and quickly added calories and jumped to 13 plus mph. I need more calories.”
Vince figured out by the end that he needed to eat more calories. If he’d just started eating enough early in the ride it would have gone quite differently.
A Little Physiology
You are always metabolizing a combination of fat and glucose when you’re riding. Riding below your anaerobic threshold (AT), also called lactate threshold, about 50% of your energy is coming from glucose and 50% is coming from fat. Above your AT the major source is glucose although you are still burning fat. The harder you ride above AT the more glucose per minute you are burning.
Glucose is stored in the body as glycogen. Your body can store about 1,800 calories of glycogen. (1,400 in the muscles, 320 in the liver and 80 in your blood.) How much you store depends on your body size and your fitness.
Your body has about 100,000 calories of energy stored as fat, an unlimited supply of fat. Even the skinniest pro has enough body fat to fuel a long race.
Protein provides only about 5% of the energy for the working muscles, although it is important for rebuilding muscle damage after a ride.
Approximate Calorie Needs While Bicycling
Many cycling computers and apps like Strava estimate how many calories you are burning based on your weight, speed and amount of climbing. If you don’t have a computer use this table to estimate your burn rate. This assumes that you are riding on the flats, not drafting and on a calm day.
- 12 mph (19.3 km/h) burns 2.5 Cal / Lb / Hr (5.6 Cal / Kg / Hr)
- 13 mph (20.9 km/h) burns 2.8 Cal / Lb / Hr (6.2 Cal / Kg / Hr)
- 14 mph (22.5 km/h) burns 3.1 Cal / Lb / Hr (6.8 Cal / Kg / Hr)
- 15 mph (24.1 km/h) burns 3.4 Cal / Lb / Hr (7.4 Cal / Kg / Hr)
- 16 mph (25.7 km/h) burns 3.7 Cal / Lb / Hr (8.1 Cal / Kg / Hr)
- 17 mph (27.4 km/h) burns 4.0 Cal / Lb / Hr (8.9 Cal / Kg / Hr)
- 18 mph (29.0 km/h) burns 4.5 Cal / Lb / Hr (9.8 Cal / Kg / HR)
- 19 mph (30.6 km/h) burns 4.9 Cal / Lb / Hr (10.7 Cal / Kg / HR)
- 20 mph (32.2 km/h) burns 5.4 Cal / Lb / Hr (11.8 Cal / Kg / HR)
If a roadie weighs 140 lbs. and is riding at 14 mph then the rider is burning 140 lbs X 3.1 Cal / lb. / hr. calculates to 434 calories / hour. These are approximate figures. The roadie is burning roughly 400 – 500 calories / hour
The American College of Sports Medicine (ACSM) recommends consuming 25 to 60 grams of carbs (100 to 240 calories) per hour after the first hour of exercise. Note that the recommendation is for calories of carbs only.
Fueling for Different Length Rides
How much fuel you should consume depends on the duration of your ride:
1 – 2 hours: About 100 – 200 total calories of carbs from a combination of a sports drink and/or a snack.
2 – 3 hours at a moderate pace: About 100 – 150 calories / hour of carbs from a combination of a sports drink and/or a snack.
2 – 3 hours at a fast pace: About 200 – 250 calories / hour of carbs from a combination of a sports drink and snacks.
4 – 5 hours at a moderate pace: About 200 – 250 calories / hour of carbs from a combination of a sports drink and snacks.
4 – 5 hours at a fast pace: About 250 calories / hour of carbs from a combination of a sports drink and snacks.
Examples of What to Eat Riding
What are the best things for you to consume? Food and drink you like and that agree with your stomach so that you’re more likely to consume them. Here are some examples:
- Sports drinks, average, 24 oz. water bottle — about 150 calories, all from carbs.
- Gel, average, 1 — about 100 calories, all from carbs.
- Banana, medium — about 110 total calories, 100 from carbs.
- Fig Newtons, 2 —about 110 total calories, 90 from carbs.
- Bagel, plain, 1 — about 290 total calories, 230 calories from carbs.
- Granola bar, average, 1 — about 115 total calories, 90 from carbs.
- PowerBar, Chocolate, 1 — 240 total calories, 180 calories from carbs.
- Clif Bar, Chocolate Brownie, 1 — 240 total calories, 170 calories from carbs.
- Oatmeal cookie, average, 1 — 81 total calories, 48 calories from carbs.
- Hammer Bar, Chocolate Chip, 1 — 220 total calories, 105 calories from carbs.
I’ve listed these in order from highest to lowest percentage of carbs / serving. Note that real food (bananas, newtons, bagels and granola bars) has a higher proportion of carbs than the different sports bars. Real food is also tastier and cheaper than sports products, which (despite marketing claims) provide no performance advantage.
Bottom line: Eat Tasty Carbs!
More Information
For pros the team chefs and soigneurs prepare a combination of sports products and regular food such as boiled potatoes, rice cakes, panini and cut-up fruit to provide an assortment of flavors. Providing a lot of variety is the key to getting through a day of racing without bonking.
My eArticle Eating and Drinking Like the Pros describes in detail what they eat for breakfast, during a race, after the race for recovery and for dinner. The eArticle includes a dozen recipes to make your own riding nutrition, each of which I tested with clients and friends. The 15-page Eating and Drinking Like the Pros is just $4.99.
The principles and recommendations for eating before, during and after a ride apply to all roadies. These are explained in my eArticle Nutrition for 100K and Beyond. Although written for roadies riding 100K and farther, all riders can learn from it. In addition to showing you how to estimate about how many calories per hour you burn I describe what to for endurance, tempo and intensity rides. I explain the difference between simple and complex carbohydrates and describe the glycemic index, which measures how fast your blood sugar rides after eating or drinking a specific item. I also discuss hydration and electrolytes. I conclude by discussing what you should eat every day to ride your best. My 17-page Nutrition for 100K and Beyond is just $4.99.
Coach John Hughes earned coaching certifications from USA Cycling and the National Strength and Conditioning Association. John’s cycling career includes course records in the Boston-Montreal-Boston 1200-km randonnée and the Furnace Creek 508, a Race Across AMerica (RAAM) qualifier. He has ridden solo RAAM twice and is a 5-time finisher of the 1200-km Paris-Brest-Paris. He has written over 40 eBooks and eArticles on cycling training and nutrition, available in RBR’s eBookstore at Coach John Hughes. Click to read John’s full bio.
This is a very educational & worthwhile article. I like the detail & the summary of food intake to the ride. I’m seriously considering buying the book. I only have a vague understanding of riding & food intake.
The calories per hour numbers are high, especially at the lower speeds. The number at 12 mph implies around 120 watts (24% metabolic efficiency).