Have you ever wondered whether walking or running to work burns more calories, even if you cover the same distance? The answer lies in the science of metabolic cost—how much energy our bodies expend during physical activities like walking and running.
Understanding metabolic cost
The energy expenditure associated with any activity is termed its “metabolic cost.” This cost accounts for the energy our organs consume to perform the activity. Researchers have studied this extensively, using measurements of oxygen consumption and carbon dioxide production to estimate the energy expended.
Back in the 1970s, scientists determined that running consumes more energy than walking for the same distance. But why is this the case?
Energy dynamics of walking vs. running
When we observe someone running, one noticeable difference from walking is the greater vertical movement of their pelvis and head. This vertical oscillation requires our lower limb muscles to generate more force, thereby consuming more energy. Essentially, part of the energy expended during running goes into lifting our bodies up and down, rather than propelling us forward directly.
This increased vertical movement during running significantly contributes to its higher energy expenditure compared to walking. Even after completing the run, our bodies continue to expend additional energy due to increased body temperature and the need to replenish energy stores. This post-exercise energy expenditure is more pronounced after running than after walking, mainly due to the higher intensity of the activity.
Speed matters
The calorie expenditure between walking and running also depends on the speed. For a “normal” walking speed of around 5 km/h, the energy expended may eventually exceed that of running if the pace is very slow. This is because our bodies have a basal metabolic rate, which means we expend a certain amount of energy per unit of time regardless of the activity’s intensity.
Conversely, at speeds exceeding 8 km/h, running becomes more energy-efficient compared to fast walking. The coordination required for fast walking increases muscle activation without benefiting from the tendon elasticity utilized in running. Studies have shown that people naturally transition from walking to running on a treadmill when the energy cost of walking surpasses that of running at higher speeds.
Practical implications
Whether you choose to walk or run to work, both activities contribute positively to your overall health and energy expenditure. Running may burn more calories due to its higher intensity and post-exercise metabolic effects, but the difference depends on factors like speed and individual metabolic rates.
In conclusion, the decision to walk or run should consider personal preference, fitness goals, and time constraints. Both activities offer substantial health benefits, from cardiovascular fitness to mental well-being. So, whether you briskly walk or opt for a morning run, the most important thing is that you’re engaging in regular physical activity—helping you stay healthy and energized throughout the day.
Remember, every step counts towards a healthier you!
