The Broad Street Run may be a couple of months away but it’s never too early for competitors to start a training plan — and that includes focusing on nutrition.

This year marks the 40th anniversary of the Philadelphia Department of Parks and Recreation’s annual Blue Cross Broad Street Run, which will be on May 5. The iconic run, which has drawn 40,000 participants, is the largest 10-mile road race in the country.

Right now, runners are beginning to increase their mileage, and work on endurance and strength, said Robin Danowski, assistant professor of nutrition at La Salle University.

“It is important in the training period for them to get adequate calories as well as carbohydrates," said Danowski.

Carbohydrates are a primary source of energy for the body. But the amount that athletes need depends on their body weight. Most athletes need to eat five to 12 grams of carbohydrates per kilogram of body weight a day, she said. Try to spread out your intake of carbohydrates during the day so your body has easily accessible forms of energy.

Whole grain breads, cereals, and pastas as well as fruits, milk, corn, and beans are all good examples of carbohydrates, she said.

Runners should also include protein in their diet to help repair and reverse muscle damage. Protein also helps lessen the fatigue brought on from training. Good sources of protein include chicken, turkey, eggs, fish, tofu, and lentils, she said.

It is important for runners to keep tabs on their weight during the weeks leading up to the race day to make sure they are not gaining or losing too many pounds, she said. It will also indicate whether they are properly hydrated, she said, as a sudden loss of about 2 percent of overall weight could be a sign of dehydration.

Later during the taper period, when runners decrease their mileage to be rested for race day, competitors should remember that they don’t need to eat as much so they don’t gain weight, Danowski said.

Taking dietary supplements may minimally improve performance but will not make much difference for the average person, she said.

The night before the race, consume a meal high in carbohydrates, said Danowski. (This is often referred to as “carb loading.”) Some people choose to have a larger meal the night before the race. Others find a smaller meal minimizes gastric distress, she said.

And stay away from alcohol the day before the event as it can interfere with the metabolism of glycogen in the liver, she said.

Danowski suggests that, immediately before the race, runners avoid high-fiber meals and foods that can lead to gastrointestinal distress such as prunes, beans, broccoli, and anything from the cabbage family.

Sports gels and bars can be used to provide energy. A handful of jelly beans can also work, Danowski said. Avoid chocolate in bars, which can melt and cause a mess, she said.

As the leader of Team Philly race training, Ross Martinson has been helping beginner to intermediate runners prepare for the Broad Street Run for 10 years.

He recommends runners identify foods that won’t upset their stomach or leave them feeling bloated on race day.

“The days before the race are not a good time to try to lose weight,” said Martinson, owner of Philadelphia Runner. “If you are short on calories, you will pay for it on race day."

Martinson, a previous top-five finisher in the Broad Street Run, stays away from a heavy carb-loading meal the night before the race. He prefers a turkey club sandwich, instead.

“You want to feel light and fast on race day,” he said

On race day, he brings a plain bagel and a banana to the race. He also makes sure to have his own water bottle so he can avoid the crowds at the first water station.

It is not all about what you eat; what you drink matters, as well.

“We know that dehydration can lead to impaired performance,” Danowski said.

The amount of fluid needed varies with each individual, she said. Sweat rates, hot and humid weather, and the intensity of the run all factor in to determine how much runners need to drink.

If your urine is pale yellow, you are adequately hydrated, Danowski said.

Plain water is good up to a certain point, but if you are running for more than 90 minutes, sports drinks can help replace lost electrolytes and carbohydrates, Danowski said. Coconut water is a good hydration source because it is high in potassium and contains sodium, both of which are lost during sweating, she said.

At the Broad Street Run, Gatorade will be available at four of the 10 water stations. Runners should look for the green cups at miles 2.2, 6.3, 7.8 and 8.5.

Make sure to pay careful attention to the cup color at the water station, said Martinson.

“I’ve definitely dumped Gatorade on my head by accident,” he said. “It can be a surprise.”