The secret to athletic success might lie in the humble potato.
New research from the University of Illinois found that potato puree is just as effective as commercial carbohydrate gel in maintaining blood sugar and performance levels in trained athletes. The trial focused on prolonged exercise, one of the most demanding types of physical activity.
Boil'em, mash'em, stick'em in a stew!
"Research has shown that ingesting concentrated carbohydrate gels during prolonged exercise promotes carbohydrate availability during exercise and improves exercise performance," said University of Illinois kinesiology and community health professor Nicholas Burd, who led the research.
"Our study aim was to expand and diversify race-fueling options for athletes and offset flavor fatigue."
Potatoes are a much more cost-effective alternative to carbohydrate gels, the team explains. Furthermore, these gels tend to be very sweet and puree would offer a savory alternative. All this sounds excellent in theory, but nobody knew how well the taters actually performed -- so the team set out to see how the two compare in practice.
The team worked with 12 participants who were healthy and devoted to their sport, averaging 165 miles (267 kilometers) per week on their bicycles. The researchers wanted their participants to be representative of athletes; so all the participants have been cycling for years and had to pass a test to qualify for the trials (a 120-minute cycling challenge followed by a time trial).
The participants were randomly assigned to one of three groups. The first group only consumed water during the experiment (control group), the second was given a commercially available carbohydrate gel, and the third an equivalent amount of carbohydrates from potatoes. The team standardized what the participants ate for 24 hours before the experiment to limit outside influences.
Throughout the exercise, the participants' blood glucose, core body temperature, exercise intensity, gastric emptying, and gastrointestinal symptoms were recorded. The researchers also measured concentrations of lactate, a metabolic marker of intense exercise, in their blood.
"We found no differences between the performance of cyclists who got their carbohydrates by ingesting potatoes or gels at recommended amounts of about 60 grams per hour during the experiments," Burd said. "Both groups saw a significant boost in performance that those consuming only water did not achieve."
Both carbohydrate groups showed almost the same increase in plasma glucose levels and heart rates, different from the water-only group. They also had better results on the trials.
One difference between the two groups, however, is that those who ate potatoes reported significantly more gastrointestinal (GI) bloating, pain, and flatulence than the other groups. The authors note that they had to eat a larger volume of potatoes to match the glucose content of the gels, which produced these results.
"Nevertheless, average GI symptoms were lower than previous studies, indicating that both (carbohydrate) conditions were well-tolerated by the majority of the study's cyclists," the researchers wrote.
"All in all, our study is a proof-of-concept showing that athletes may use whole-food sources of carbohydrates as an alternative to commercial products to diversify race-fueling menus," Burd said.
The paper "Potato ingestion is as effective as carbohydrate gels to support prolonged cycling performance" has been published in the Journal of Applied Physiology.