Ever since I've started running like a penguin with its butt on fire I've saved so many precious calories

How are they measuring wasted energy? Like, if a get from point A to point B then how was that energy wasted? How does a penguin waste less? I'm confused by this stat.

Yeah it sounded like bullshit to me since humans are so energy efficient we can hunt by running after animals until they're exhausted. Seems like it's from this 2000 study published in Nature.

Penguins use twice as much calories moving around on land as other similar sized land animals. It was thought this was due to them being more adapted to swimming which resulted in them waddling when they walked on land which was inefficient.

Turns out that thought was only half true. They use more energy to get around on land because they're not adapted to walking, but waddling isn't the cause. Waddling is actually more energy efficient, for the speed penguins move at. The research suggested the excess energy use is due to the muscle fibers in their legs. Their short legs require powerful, but inefficient, muscles to support their large bodies. The waddling might actually be a way to cut down on their energy use while on land.
- From what I've read we are energy efficient but this is not the main reason why we are good persistent hunters.
  
  We have two main advantages, one we can stand above the tall grass to spot our prey from afar but mainly we sweat !
  
  We are extremely good at regulating our internal temperature in hot climates compared to other animals, this way we can just follow them until they overheat at which point they physically have to stop.
  
  This is also why persistent hunting is practiced by tribes in the hot savanna of Africa, I have not heard about any example of persistent hunting in cold climates.
- Former penguin biologist here, it's bullshit.
I think it's the percent of your kinetic energy you lose with each stride. I have no idea how that would be measured, but it makes the most sense.