Cycling Nutrition with Monique Ryan: That bloated feeling

Dear Monique,I have a very distended stomach after cycling for more than an hour. I used to think that it only happens on very long rides like the Leadville 100, but have noticed that it occurs on much shorter rides too. It doesn’t seem to matter if I only drink water or any combo of energy drinks and gel or bars. I am a bit concerned that the nutrition I take in isn’t getting past my stomach until I am done riding. I have experienced severe cramping in my legs about three-fourths of the way through a race and have wondered if the bloating is related and what to do about it. Thanks for your

Dear Monique,

I have a very distended stomach after cycling for more than an hour. I used to think that it only happens on very long rides like the Leadville 100, but have noticed that it occurs on much shorter rides, too. It doesn’t seem to matter if I only drink water or any combo of energy drinks and gel or bars. I am a bit concerned that the nutrition I take in isn’t getting past my stomach until I am done riding. I have experienced severe cramping in my legs about three-fourths of the way through a race and have wondered if the bloating is related and what to do about it. Thanks for your time and help.
Gary

Dear Gary,
Your problem is not uncommon as many cyclists often fill their stomachs with a variety of sports nutrition products in an attempt to meet higher energy needs during intense training and racing. When you consume various sports nutrition products in attempts to hydrate and fuel-up, these products are still essentially outside your body. First, they need to make their way through your gastrointestinal system, and then get into your bloodstream. The speed at which the fluid, fuel and electrolytes that you ingest become available to your body is affected first, by how quickly they empty from your stomach, and then by how quickly they are absorbed through the small intestine.

Unfortunately, what can result from a focused attempt to obtain carbohydrate calories for high fuel needs, is that your stomach becomes overfull and does not empty quickly or comfortably. And if fluids and foods are slow to empty from your stomach, they can’t reach your small intestine quickly, making fluid, energy, and electrolytes available to your body. So it is possible that slow stomach or gastric emptying that delays the optimal delivery of fluid, fuel, and electrolytes may result in leg cramping in susceptible endurance athletes, as well as not adequately offset dehydration, replace electrolytes, or offset muscle glycogen losses. Clearly, fluid and food choices that allow for optimal gastric emptying are going to have the most positive effect on athletic performance, and prevent other related side effects.

Several factors are know to slow down gastric emptying: Exercise above 70 to 75 percent of  VO2 max, dehydration, mental stress or anxiety, higher calorie content of beverages, high osmolality of a drink (refers to the total number of particle such as carbohydrate and sodium in the solution).

In contrast, having a larger volume of fluid in your stomach (before some degree of dehydration sets in) can also encourage your stomach to empty more quickly.

Gastric emptying of liquids is clearly affect by a number of factors, with the most important being volume and energy content of your drink. Osmolality is really of secondary importance and probably has little effect on gastric emptying when your fluid choices are within the range of most commonly consumed sports drinks.

Most importantly, increasing the carbohydrate content of your intake beyond what you can consume from a sports drink will delay stomach emptying. Most sports drinks fall in the range of 6 to 8-percent carbohydrate concentration, which is a good balance of fluid and carbohydrate for endurance training in warmer weather.

When ingesting a sports drink in warmer weather, your goal should be to match your sweat rate as closely as possible, to minimize underdrinking or prevent overdrinking. Check your weight in the buff before and after training. Each pound of weight loss represent 16 ounces of sweat that you did not replace with fluid during training. Keep track of how much fluid you consumed. If you add the fluid consumed to the fluid equivalent of the weight loss, you can see what your total sweat losses were during that ride.

Once you have a sense of your sweat rate, you can see just how closely you can match your sweat losses with your drinking efforts. Just as sweat losses among cyclists can vary, so can gastric emptying rates. However, practice in training can help to optimize your ability to take and tolerate more fluid, and consequently deliver more carbohydrates and electrolytes to your body. Starting a training ride or a race with a half-full stomach, and drinking early on during exercise will encourage faster gastric emptying. Drinking larger gulps also encourages your stomach to keep emptying.

Once you have established your drinking regimen in relation to your sweat rate and personal tolerances, then you can determine how many grams of carbohydrate that you consume per hour. Generally, harder endurance efforts require about 1 grams of carbohydrate per kilogram of body weight. However, for ultraendurance efforts lasting longer than four hours, your may find that you need additional fuel. That’s where gels and bars come in. If you add these concentrated carbohydrate products into your fueling plans, keep in mind that they will slow down gastric emptying. Consuming them with water is best, and try to use them gently in small, regularly spaced doses as needed. If you are significantly dehydrated when you consume these more concentrated products, delayed stomach emptying and discomfort could result- so please experiment with these products in training.

Example:170 lb. / 77 kg cyclistSweat rate: 2 quarts per hourFuel needs: 77 to 92 g carbohydrate per hour (1 to 1.2 grams/kg)

If this athlete consumes 1.5 quarts (48 ounces or 1440 ml) of a 6-percent concentration sports drink per hour, he will receive 84 g of carbohydrate for fueling needs.

Focused drinking with a sports drink should always be your primary nutrition strategy during longer rides.

Monique


Monique Ryan Monique Ryan, MS, RD, LDN is a nationally recognized nutritionist with over twenty-two years of experience and is owner of Personal Nutrition Designs, a Chicago based nutrition consulting company that provides nutrition programs for endurance athletes across North America. Monique consults with the Chicago Fire Soccer Team, and was the nutritionist for Saturn Cycling from 1994 to 2000. She has also consulted with the Volvo-Cannondale Mountain Bike Team, the Gary Fisher Mountain Bike Team, and the Rollerblade Racing Team. Monique has consulted with USA Cycling, and was a member of the Performance Enhancement Team for the Women’s Road Team leading to the 2004 Athens Olympics. She has also provided nutrition consultation services to USA Triathlon for coaching clinics, athlete clinics, and for the resident athlete team and was a member of the USAT Performance Enhancement Team for the 2004 Athens Olympics. Monique is the author of “SportsNutrition for Endurance Athletes,” 2nd edition (March 2007), from VeloPress,which provides sports specific nutrition for road cycling, mountain biking, running, triathlon, swimming, rowing, and adventure racing. She is also author of “PerformanceNutrition for Winter Sports” (PeakSports Press), “Performance Nutritionfor Team Sports” (PeakSports Press), and “Complete Guide to Sports Nutrition. Monique is a regular contributor to VeloNews, Inside Triathlon, Outside, and ACE Fitness Matters. Please send your questions to velonewssteve@competitorgroup.com.