By Arnie Baker, M.D.
It’s pretty obvious that hydration and nutrition is important during cycling, but it’s also helpful to pay attention to it leading up to an important event.
If you take time to prepare the night before, you’ll be much more likely to ride strong. Here are my recommendations on preparing nutritionally for your next big ride or race.
Key Cycling Nutrition Points
- Start exercise well-hydrated.
- Start exercise glycogen-loaded in both muscles and liver.
- Dinner: Pre-event meal high in carbohydrate. If planning to exercise for more than 4 hours, or 2 hours in high heat and humidity, add salt to foods.
- Breakfast: Cyclists should aim for at least 1,000 calories. Runners may not be able to eat as much — perhaps only a few hundred. Walkers and triathletes will be in between .
- Pre-workout calories benefit both endurance and strength athletes, both aerobic and anaerobic work.
- Start prolonged exercise in the heat salt-loaded.
- Be prepared for start delays. Have easily digestible fluids and calories available at the event in case of a start delay.
Hydration
Exercise can be dehydrating. It is best to start well-hydrated.
Intracellular hydration is different from vascular hydration. Drinking 16 to 32 ounces (500 to 1,000 milliliters) in the hour before a workout or event may improve vascular hydration, but may not improve intracellular hydration.
Intracellular hydration requires adequate hydration in the 24 to 48 hours before exercise.
Although athletes are often advised to drink 16 to 32 ounces in the hour before exercise to assure adequate hydration, this is not always the best strategy.
If you are already well-hydrated, and your workout or event does not allow for easy urination, you may not want to drink that much before exercise and be forced to race with a full bladder.
For example, if you are going to race a 20-kilometer (12.4-mile) bicycle time trial under temperate conditions, dehydration during the roughly 30-minute event is not likely. If you have kept up with losses up to the hour before your race start, drinking a full water bottle (16 ounces, 500 milliliters) within 30 minutes of your race start is not likely to improve performance, and may worsen it.
On the other hand, keeping up with fluid losses, and drinking a bottle just before the start of a hot 2-hour hilly cycling road race makes sense, especially if fluids on route are limited, you are discrete, and you have the skills to urinate while riding.
Calories
You need fuel to work. Starting hungry – calorically deficient – is a bad strategy. If exercising at high intensity, you’d like your stomach empty. You do not want to have a heavy meal in the minutes before an all out effort. This is especially true for runners.
On the other hand, if exercising for many hours at moderate or low intensity, solid food near the start time may be fine. This is especially true for cyclists.
Planning to ride a recreational century? The 100 miles will burn about 3,000 calories. By pacing, riding moderately at the start, it may be easy to have a few hundred calories of solid food just before the start.
Top Up Blood Sugar and Glycogen
For basal metabolism and exercise associated with warming up, you may use 250 calories per hour. Ingesting this amount of caloric energy in the hours before your workout or event may allow you to keep glycogen levels in both liver and muscle high and prevent lowering of blood sugar levels at the start.
The closer to your hard workout or intense event start, the more you will rely on liquids, rather than solids, to provide calories.
Carbohydrate in solution may not be necessary for events as short as 30 minutes, although some studies have shown benefit even for events of this duration.
For workouts or events lasting an hour or longer, topping up energy supplies is important. The longer your event, the more important it is to start with a full tank.
Caloric Mix
Big meals and fatty meals ingested within an hour of intense exercise can cause performance problems. Fats delay the emptying of the stomach. When blood supplies are diverted to the intestines to aid digestion, less blood is available to go to the working muscles. Intestinal cramps may also result.
If you’re entering a road race of 70 miles and it is not going to get “hot and heavy” until two hours or 50 miles into the race, a balanced meal, not based solely on carbohydrate, may stay with you longer, helping to mete out energy over the few hours of your event. Tour de France riders, for example, typically include fats and protein along with their pre-race carbohydrate meals.
Some foods may have the right caloric mix, but be hard to get down. For example, even if comprised mostly of carbohydrate, some energy bars may feel like balls of cardboard in the mouth and stomach.
Insulin and Low Blood Sugar Levels
When carbohydrate solutions are ingested 30 minutes before exercise, insulin levels may rise and blood sugar levels may fall immediately before exercise starts.
Depending upon type of sugar, formulation, and the exact timing of the sugar load, pre-exercise carbohydrate may also result in higher or lower blood sugar levels during the first 10 minutes of exercise. Even if blood sugar levels fall, studies generally show that performance is the same or improved.
Pre-event feedings have concentrated on carbohydrate calories. Feedings with medium-chain triglycerides have not been shown to improve performance.
Missing Breakfast?
Runners often race without breakfast; this is not a recommended strategy.
An evening meal with a high fat content may help, because liver glycogen stores may be relatively spared by the slower digestion and metabolism of fats and the resulting longer entry of nutrients from the gastrointestinal tract into the bloodstream.
Salt Loading
In general, it is probably best for good health to consume a diet relatively low in sodium.
If you are going to workout or race for several hours or more in the heat, it may be difficult to replace sodium during your exercise. Adding a tablespoon of salt (6,600 mg sodium) to foods over the course of the 24 hours before your exercise may be a good strategy.
The best way to get extra sodium is by eating salty foods. The night before long workouts in the heat add some salt to your pasta meal or have high sodium foods such as pizza, pretzels, or soup. Tomato juice and V-8 are high-sodium fluids.
It is preferable to eat salty foods or drinks rather than ingest salt tablets. Studies have shown that salty foods and drinks appropriately stimulate thirst, and so prevent the unintentional ingestion of dangerously high amounts of sodium.
Keep Pre-Event Supplies Handy
Start delays of several hours or longer may occur because of event permitting problems, weather delays, or roadwork problems. Be prepared to keep fluids, calories, and even salt levels high, with a cooler stocked with solids and liquids. Be prepared for short delays with easily digestible supplies. Be prepared for substantial delays with “real food.”
Follow these tips, and you’ll be much more likely to finish your next important cycling event without bonking, cramps or suffering from gastrointestinal distress.
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