The majority of people who run do not set their intensity by measuring the weight on their knees. If you take someone with a fixed fitness and reduce their mas

The majority of people who run do not set their intensity by measuring the weight on their knees. If you take someone with a fixed fitness and reduce their mass, they will expend less energy per unit of time, but in order to effectively train you need to keep a target intensity, so you increase the amount of distance you cover per step or increase your cadence, either / both of which increases the energy consumed per unit of time. That's all I mean when I say that you just go faster.