A positive outcome of the many COVID-19 restrictions has been a huge boom in bicycling (New York Times, August 17, 2020). If you are a regular cyclist or are new to the sport, be proud. Humans riding on bicycles are more energy-efficient than any other form of transportation and any other animal. Vance Tucker of Duke University compared bicyclists to people and animals running, birds flying and fish swimming, as well as to people in motor-powered cars, boats, trains and planes (J Exp Bio, 1973;68(9):689-709). The less energy per weight you use to travel over a distance, the more energy-efficient you are. He found that the most efficient creature without mechanical help is a condor. With mechanical help, the cyclist comes out on top.
Here is a partial list, ranked from most to least energy-efficient: human on a bicycle, condor, salmon, horse, human in a jet plane, human walking, human running, human in an automobile, cow, sheep, dog, hummingbird, rabbit, bee, and mouse. Tucker found that rabbits, mice, bees and hummingbirds use the most energy per weight and therefore are very inefficient and tire the earliest.
A person on a bicycle is more energy-efficient than one using an automobile, motorcycle, train or plane, even though he is much slower. If you compare the amount of calories burned per mile in bicycling to other forms of locomotion, you will find that 100 calories supplies an average cyclist for three miles, a walker for one mile and a car for only 280 feet. A walking human uses 0.75 calories of energy per gram of body weight for each kilometer traveled, while a cyclist uses only a fifth as much, 0.15 calories per gram per kilometer. The WorldWatch Institute reported that when you ride a bicycle you use only 35 calories per mile, while walking requires 100 calories per mile, buses and trains use about 900 calories per mile per person, and a car uses about 1860 calories per mile (Ergonomics, 2008 Oct;51(10):1565-75).
Slow Riders Use Less Energy Than Fast Riders
Cycling is so energy-efficient that a good rider can go extraordinary distances. In 2014, Christopher Strasser won the Race Across America by cycling 3,098 miles in a record seven days, 15 hours and 56 minutes. He averaged 16.42 miles per hour. The record for a woman was set in 1995 at an average speed of 13.23 mph. Interestingly, slow riders use less energy per mile than fast riders. During a one-hour ride, a person riding a touring bike for nine miles burns 135 calories with an average power of 50 watts, while in an hour an experienced bicycle racer can go 30 miles but will burn 2150 calories and produce approximately 500 watts or 0.67 horsepower. You burn more calories per mile primarily because the faster you ride, the greater the wind and air resistance. Resistance varies with the cube of your speed. A recumbent bicycle is more energy-efficient because being lower to the ground reduces the size of the bike and body that is being blocked by wind and air resistance (Proc Biol Sci, 2001 Jul 7;268(1474):1351-60).
Consider an Electric-Assist Bike
Electric-assist bikes (bicycles with small motors, or “ebikes”) are becoming incredibly popular and make it possible for people who have not ridden in years to get all of the benefits of cycling. Try an ebike if you have weak muscles or lack of conditioning for any reason, or fear that you will not be able to keep up with other riders, or just a desire to have a little extra help when you want it. See my report on Electric-Assist Bikes and Trikes. Caution: Check with your doctor before starting a new exercise program.
Dr. Gabe Mirkin is a Villager. Learn more at www.drmirkin.com.
