Ever hit the wall? Then you understand the title of this column!
In last week’s newsletter there was an excellent column Cycling Nutrition: How to Eat during Rides by Arnie Baker, MD. I’ve coached at camps with Dr. Baker and have several of his books. His key points are:
- For events longer than one hour, consume at least 300 calories per hour of exercise
- Aim for at least 8 ounces (250 milliliters) of fluids, every 15 to 30 minutes, depending upon the heat.
- Have carbohydrate-in-water solutions (for example, maltodextrin or sports drinks), rather than plain water.
- Carry two water bottles. Or use a hydration system (for example, CamelBak).
- For multi-hour events in conditions of heat and humidity, consume salty foods, and sodium-rich solutions and gels.
In this column I’ll amplify on his recommendations for eating and salt and discuss the potential problems of his recommendations on hydration.
Dr. Baker writes, “It is typical to use 2,500 to 3,000 calories during a cycling century (one-hundred miles). Energy loss depends upon work rate. Work rates may be up to 1,200 calories per hour. Some of this energy comes from the body’s stores of carbohydrate (glycogen) and fat.
Your body has about 1800 calories of carbohydrates stored as glycogen in your muscles and liver. You also have nearly 100,000 calories of fat! Your glycogen stores are limited to a few hours of hard riding, which is why eating carbs is so important.
Dr. Baker continues, “Some energy needs can be met by consuming calories while exercising. Depending upon your size, your body can use up to 300 ingested carbohydrate calories per hour (about 1 gram per kilogram per hour). As a rule, try to consume this many calories for every hour you exercise. Multiple studies confirm that athletes perform better when they fuel while exercising.
Consuming 300 calories of carbs per hour is not the consensus recommendation.
Eating 30 to 60 grams (120 to 240 calories) per hour is recommended in the Position Paper: Nutrition and Athletic Performance by the American Dietetic Association, Dietitians of Canada and the American College of Sports Medicine.
Carbohydrate Supplementation During Exercise: Does It Help? How Much Is too Much by Asker Jeukendrup, PhD states, “Carbohydrate from a single source, such as glucose, can only be oxidized at rates of approximately 60 g/h. When a combination of carbohydrates is ingested (e.g., glucose and fructose) oxidation rates of slightly more than 100 g/h can be achieved if large amounts of carbohydrate are ingested (e.g., > 140 g/h).”
Different carbohydrates (maltodextrin, sucrose, glucose, fructose, etc.) are digested by different metabolic pathways, which is why you can digest more per hour if you consume several kinds of carbs.
Dr. Baker says, “Calories can come from solids, gels, or solutions.”
Yes, sports nutrition products can provide the calories you need; however, they don’t result in better performance than real food, which is cheaper and usually tastier.
Danger of Drinking Too Much
Dr. Baker writes, “Fluid is lost primarily in the urine and through sweating. The kidneys have a tremendous ability to dilute or concentrate urine. They can rid the body of large excesses of fluids when the need arises. They can also concentrate urine if a person becomes dehydrated.”
The American College of Sports Medicine published a Position Stand Exercise and Fluid Replacement in 2007. It states that during exercise and heat stress urine output decreases. “When fluids are over consumed during exercise there may be a reduced ability to produce urine to excrete the excess volume.” In other words if you drink an excessive amount of fluid because you’re concerned about dehydration you may not urinate all the excess fluid.
Dr. Baker continues, “Sweat rate depends upon work rate and climate (heat and humidity). During hard work in hot desert-like conditions, it is possible to lose more than a couple of quarts (liters) per hour. Sweat rates have been measured up to 3.5 quarts per hour and 17 quarts per day.”
Sweat rate does depend on how hard you are working and how hot it is. However, sweat rate is very individual. It depends on how big you are and your gender. Women have lower sweat rates primarily because of smaller bodies. As you become more acclimated to riding when you are hot, you start to sweat at a lower core temperature, and you sweat more, which keeps your core temperature lower. You’ve probably been on a ride in the heat when some roadies are dripping sweat and others are barely sweating.
Dr. Baker writes, “For events longer than one hour, or one-half hour in the heat, water replacement is important. … Aim for 8 ounces of fluids every 15 minutes in the heat. That is about one quart (liter) every hour. Although you may lose more, it is doubtful that drinking more will be helpful because your body probably cannot process more than that. (With nutritional training, athletes learn to tolerate up to 12 ounces every 15 minutes.)”
The ACSM position stand Exercise and Fluid Replacement states, “In general, dehydration is more common, but over-drinking with symptomatic hyponatremia is more dangerous. Dehydration can impair exercise performance and contribute to serious heat illness …. while exercise-associated hyponatremia can produce grave illness or death.”
Hyponatremia is abnormally low blood sodium. The paper Hyponatremia among Runners in the Boston Marathon states, “We observed that hyponatremia occurs in a substantial fraction of marathon runners and can be severe. The strongest single predictor of hyponatremia was considerable weight gain during the race, which correlated with excessive fluid intake.” Although the study was of runners the same points apply to roadies. When you drink too much, you can’t urinate out the excess fluid so you start retaining fluid and gain weight.
The paper’s key conclusion is, “Because runners vary considerably in size and in rates of perspiration, general recommendations regarding specific volumes of fluids and frequencies of intake are probably unsafe and have been superseded by recommendations favoring thirst or individual perspiration rates as a primary guide.”
Put simply drink to satisfy your thirst, not according to a schedule.
Dr. Baker’s two other hydration recommendations are to drink a something with carbs and to carry two bottles or a hydration system. Drinks with carbs are easier to digest and provide some of the calories you need. I recommend that my clients carry two bottles or one bottle and a hydration pack. One bottle is a sports drink and one with water. Which sports drink is best? In terms of performance they’re all the same – drink the one you like.
Dr. Baker writes, “Sodium is the electrolyte priority for the aerobic endurance athlete.”
Sodium is the primary electrolyte in sweat. The amounts of the other electrolytes are very small and you get plenty in a normal diet.
Dr. Baker notes, “A low concentration of sodium in the blood [hyponatremia] is associated with weakness, fatigue, seizures, and occasionally death.”
He continues, “The body loses about one gram of sodium per quart (liter) of sweat. After a gallon (4 quarts, 4 liters) of such loss, the average total daily intake of sodium may be inadequate to meet demands, and the blood sodium may drop. In temperate weather conditions, this may take 4 or 5 hours. In high heat conditions, sodium depletion can occur in just a couple of hours.
“For aerobic-endurance athletes, it is reasonable to plan on an intake of up to a maximum of one gram (1,000 milligrams) of sodium per liter of fluid loss. This is about one-half teaspoon of salt. Salt in beverages is often unpalatable. Salty-snacks, including low-fat pretzels, saltines, and pickles are often a good choice for athletes at rest stops. Carry salt and sprinkle it on oranges or cantaloupe slices.”
Note that although Dr. Baker is recommending something like sports drink for fluid replacement, he isn’t recommending sports drinks to replace sodium. The sodium concentration in sports drinks is less than the sodium concentration in your blood so drinking a sports drink will dilute your blood sodium just like drinking water.
He also isn’t recommending taking electrolyte replacement supplements. One popular supplement contains 120 mg of sodium per capsule. To consume 1,000 mg of sodium you’d have to take eight capsules! Some supplements do contain significantly more sodium per capsule. If you want to use a supplement read the label to determine the amount of sodium. I carry salt tablets.
If you eat properly then you will ride well and enjoy riding.
Here are four related columns of mine:
- 14 Nutrition Tips for Endurance Riders
- Nutrition for Performance
- Learning from the Pros: Cycling Nutrition
- Eat, Race, Win Lessons from the Tour de France
I’ve also written several eArticles on nutrition:
My eArticle Nutrition for 100K and Beyond combines the best current research and my 40 years of riding and coaching to teach you proper sports nutrition. I explain the types of fuel, how to estimate how many calories you burn on a ride and what to consume during the ride. I also explain what to eat before and after the ride. My 17-page Nutrition for 100K and Beyond is just $4.99.
Nutrition for 100K and Beyond is included in my bundle of three eArticles Endurance Training and Riding:
- Beyond the Century describes training principles and different training intensities and how to integrate these into program of long rides. Although written for roadies doing longer events all of the principles also apply to shorter events. I lay out an 8-week plan to build up to a century and then a 200-km ride (about 125 miles), plans, which could be easily adapted to shorter rides.
- Nutrition for 100K and Beyond provides you with the information you need to fuel your engine before, during and after endurance rides.
- Mastering the Long Ride gives you the skills you need to finish your endurance rides. Effective training provides your base, and proper nutrition gives you the fuel. The key to success is to use your smarts to complement your legs.
The 50-page Endurance Training and Riding bundle is $13.50
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. What they consume may surprise you in terms of the variety and seemingly unusual nature of some of the food and drink. The findings hold lessons and benefits for cyclists at all levels. Eating and drinking like the pros offers you the same nutritional benefits, which you can customize to our own needs – typically at a fraction of the cost of commercial sports food and drink, if you choose to make your own. I worked with a professor of nutrition and an expert on hydration and electrolytes (both experts are cyclists). 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.