- Researchers say our genetics are designed to make us run at energy-efficient speeds to preserve calories.
- They say that may explain why some runners have trouble improving their race times.
- Experts say there are ways to train your body to overcome this hereditary limitation.
Your brain may tell you that you need to run faster to become a better runner.
But your genetics may have a different idea.
That might be why it’s so difficult for long-distance runners to improve their times.
Researchers from Stanford University in California and Queens University in Ontario combined data from runners monitored in a lab, along with 37,000 runs recorded on wearable fitness trackers.
They found humans’ natural tendency is to run at a speed that conserves caloric loss, something that racers trying to improve times must overcome.
The scientists studied running mechanics for 15 years but hadn’t studied real-world running until this research project.
“We were able to fuse the two datasets to gain new insights and combine the more messy wearable data with the gold standard lab experiments to learn about how people run out in the world,” said Jennifer Hicks, PhD, the study’s co-author and the deputy director of Stanford’s Wu Tsai Human Performance Alliance, in a statement.
The team was surprised to find the consistency they found across the combined datasets.
“We intuitively assume that people run faster for shorter distances and then would slow their pace for longer distances,” said Jessica Selinger, PhD, a study co-author and a neuromechanics researcher at Queens University, in a statement.
That turned out not to be the case.
Most of the runners analyzed ran at the same speed, whether it was a short run or a long run over 10 kilometers.
The authors reported that from an evolutionary perspective, it makes sense that humans would run at the speed using the least amount of energy. It’s a trait that has also been observed in animals.
However, humans now have different reasons for running. When the goal is speed, humans have to find different ways to get around their natural tendency to conserve energy.
“We can train the body to become more efficient even when running at faster speeds,” Todd Buckingham, Ph.D., the chief exercise physiologist at The Bucking Fit Life in Atlanta, told Healthline. “A lot of this has to do with the neuromuscular adaptations that occur within the body.”
“Imagine there are 100 muscle fibers that are firing in your legs while you’re running,” he explained. “Of those 100 muscle fibers, only 50 actually need to be firing in order to move your body forward at the speed you’re running. This is because the body has not established the most efficient neuromuscular pathways. Instead of firing only the muscles that are required, it overcompensates because these efficient pathways have not been established.
“It’s like doing a maze,” he added. “The first time you do the maze, you’re going to take a lot of wrong turns and end up doing extra work. However, after several repeated attempts of the same maze, you become faster and more efficient, only taking the route that leads you to the exit the fastest. The connection between our nerves and muscles responds in much the same way. So, the more you run, the more efficient you become because you’re teaching the body which fibers should be firing and which shouldn’t.”
Each person has different muscular abilities translating to how they perform, said Dr. Theodore Strange, the chair of medicine at Staten Island University in New York.
How they perform beyond that can depend on how they take care of themselves.
“Based on body size, muscle mass, weight, etc., each runner has an energy efficiency range,” Strange told Healthline. “Runners can improve their times with good nutrition, knowing and maintaining a good weight that one is comfortable with, stretching before and after exercising, better than adequate hydration, resting appropriately, and setting goals for both time and distance.”
Strange said runners having enough water in their body is “paramount.”
“Drinking a lot of electrolyte replacement drinks with high sugar is not recommended as routine. These drinks should be used to replace fluids after active running with a lot of sweating,” Strange said.
“Running faster requires practicing and monitoring time based on distance and speed,” he said. “This is most easy to do on a track and increasing speed weekly for interval distances will improve time. Interval speed training and increasing the interval time helps.”
Running at a comfortable weight for each individual is important, but weight loss, when appropriate, can help improve running time.
Experts also advise people not to set unrealistic expectations and to be patient with weekly increases in speed and distance. They can then get comfortable with certain distances and time, especially for beginners.
“An example would be to start at 5 (kilometer) run and get to a level of speed that is comfortable,” said Strange. “Run a few races as the competitive atmosphere and adrenaline help also. Finally, always stretch those muscles out and keep limber especially post running. This helps prevent injuries like sprains and strains.”
The study’s authors said their research also produced a few tips to share.
“Listening to music with a faster pace has been shown to help speed up stride frequency, which can then increase running speed,” Selinger said. “Picking faster running buddies can give you a boost.”
Fitness data from wearables can also provide insight.
“You can look at connections with the built environment and access to recreation resources and start to layer all of that data to really understand how to improve physical activity and health more broadly,” said Hicks.