Walk vs. Run: Which is Most Efficient?
When you’re trying to conserve energy, the fastest way to travel isn’t usually the best
I backpack at least once every summer. On these trips, I usually travel 15 miles (24 km) each day, for multiple days, trekking from one secluded valley to another and carrying all my supplies. The fewer calories I burn, the less food I need to carry. In my case, energy efficiency becomes a critical planning question: Do I consume fewer calories walking or running?
The Data
There is nearly a century of academic research on locomotion efficiency. I’m partial to this 1976 paper that used “high-speed” film (my GoPro records at a higher frame rate) to measure limb movement and calculate the total energy expenditure to maintain movement. The authors found that walking is more efficient at typical speeds, but rapidly loses efficiency vs. running as speed increases.
Recent research continues to produce similar results. Walking is most efficient at about 3.5 MPH (5.6 KPH) runners have fairly consistent energy consumption, gradually dropping with speed.
