A jog is a fun way for many recreational runners to stay fit and burn calories. However, it turns out that people tend to settle into the same, comfortable pace on short and long runs — and that pace is the one that minimises their body’s energy use over a given distance.
Jessica Selinger, a biomechanist at Queen’s University in Kingston, Canada, says, “I was really surprised.” “I would have assumed that people run faster over shorter distances and slower over longer distances.”
Selinger and colleagues combined data from over 4,600 runners who completed 37,201 runs while wearing the Lumo Run fitness device with lab-based physiology data. The study, published on April 28 in Current Biology, also demonstrates that running faster or slower than one’s optimum speed consumes more energy.
“There is a speed that will feel the best for you,” Selinger says. “At that speed, you’re actually burning fewer calories.”
The runners ranged in age from 16 to 83, with BMIs ranging from 14.3 to 45.4. However, regardless of the participants’ age, weight, or gender, or whether they ran only a limited range of distances or runs of varying lengths, the same pattern appeared in the data repeatedly.
According to Melissa Thompson, a biomechanist at Fort Lewis College in Durango, Colorado, who was not involved in the new study, researchers previously believed that running was performance-driven. She claims that the new study is “about preference, not performance.”
According to Selinger, the majority of related research has been conducted in university laboratories, with study subjects who are generally younger and healthier than the general population. The researchers could track many more runs in real-life situations by utilising wearable gadgets than is possible in a lab. This enabled the researchers to examine a “far bigger cross section of mankind,” she says. Treadmill studies assessing energy usage at various speeds with participants representative of those in the fitness tracker data were utilised to establish the most energy-efficient speeds.
The study is noisier than lab data since it involves a wide variety of situations and does not control for factors like fasting before running. Nonetheless, the sheer volume of real-world runs captured by the wearable devices supports a convincing general rule about how humans run, according to Rodger Kram, a physiologist at the University of Colorado Boulder who was not involved in the study. “I believe the rule is correct.”
The findings do not apply to very long runs when exhaustion sets in, or to race performance by professional athletes or those who intentionally train for speed. And a runner’s ideal speed might fluctuate over time due to factors such as training or age.
There are some fast ways for folks who wish to speed up and burn more calories to temporarily overpower their body’s natural inclinations: Listen to lively music or jog beside someone who moves quicker, suggests Selinger. “However, it appears that your choice is to revert to that optimum.”
The findings correspond to observations of optimal pacing in animals such as horses and wildebeests, as well as how humans tend to walk at a speed that minimises their individual energy use (SN: 9/10/15).
According to coauthor and Stanford University biomechanist Scott Delp, “it makes sense that humans would be adapted to run at an optimum speed for minimising energy use.” Consider yourself an early human ancestor out hunting challenging prey. “It could be days before I get my next meal,” he admits. “So I want to expend the least amount of energy getting there.”