Within the world of cycling, “to Everest” means to ascend and descend the same mountain repeatedly until the total elevation gained equals that of Mt. Everest, which is 8,848 meters. A record for this challenging feat was established a few years back, but it sparked a discussion about the significant tailwind the cyclist had during the climbs. How much of an advantage does tailwind provide to a cyclist during an uphill ride? Should there be restrictions on permissible wind speeds?
In cycling, “to Everest” refers to the challenge of going up and down a mountain until the cumulative height matches Mt. Everest’s elevation — 8,848 meters.
Following the establishment of a new “Everesting” record a few years ago, a lively discussion emerged on social media regarding the powerful tailwind of 5.5 meters per second (equivalent to 20 kilometers or 12 miles per hour) that accompanied the cyclist during the climbs. How beneficial was this tailwind? Should regulations be set on wind speed during such attempts?
Martin Bier, a physics professor at East Carolina University in North Carolina, became interested in this discussion and decided to delve into the physics behind it, leading to a small research project. He published his findings in the American Journal of Physics by AIP Publishing, revealing that the influence of wind is actually minor.
To provide some context: In the world of physics, cycling is simpler to analyze than running. “In running, the legs are constantly speeding up and slowing down, and the runner’s center of mass oscillates vertically,” explained Bier. “Cycling, on the other hand, relies on ‘rolling,’ which is more fluid, quicker, and more efficient; you are primarily working against gravity and friction.”
However, there is a peculiar aspect regarding air resistance. The force exerted by air friction increases with the square of your speed. For cyclists on flat surfaces or descending, air resistance typically constrains speed; thus, to double your speed, you would need to exert four times the force, and to triple your speed, nine times as much force is required. Conversely, when cycling uphill, speeds are comparatively lower, making air resistance less significant.
“When you’re riding up a hill, increasing your power output results in a proportional increase in your speed. In competitive cycling, attacks often happen on inclines because additional effort yields a larger advantage,” Bier mentioned.
During a solo Everesting challenge, the calculations involved are quite simple. The cyclist isn’t being pulled along by another rider, meaning the primary factors are watts of power, gravity, and resistance.
“At first glance, one might think a strong tailwind could offset the challenge of climbing hills,” said Bier. “You could imagine riding uphill as if it were flat due to the tailwind, with the downhill benefiting from a headwind that seems to balance it out. But that’s not accurate—the squaring of speeds complicates matters!”
Bier’s research indicates that while a tailwind may provide some assistance while climbing, the effort involved in ascending is largely about overcoming gravity. The downhill portion, while quicker and shorter, is where the headwind significantly impacts speed, typically reaching around 80 kilometers per hour (49.7 mph).
<p“Air resistance increases with the square of the speed, which leads to considerable reductions in speed when facing a headwind on the descent,” Bier asserted. “The advantage of the tailwind while climbing is effectively negated.”
The clear takeaway from Bier’s analysis is that waiting for ideal wind conditions won’t enhance your Everesting performance. “There are no shortcuts,” he emphasized. “To excel at Everesting, one must focus on losing weight and increasing power output through training. That’s what truly makes a difference—there’s no escaping that.”
