The video · check no. 2

Carbon “super shoes”, checked

The famous number for carbon-plated running shoes is 4%. Across fourteen studies and 271 runners, the average is about 2.75% — and nearly all of it was measured on flat ground. The whole check in four and a half minutes, narrated.

4:45 · 1920×1080 · English subtitles, burned in Download the MP4

Every number in this video is traced to a source in the full write-up: read the complete check — fourteen studies, 32 sources, and the fine print that a video can't carry. Where something is our own estimate rather than a measurement, we say so.
Want to run your own numbers? The free calculators — pace, race predictor, heart-rate zones, climbs and aero — each show the formula they use.
Music: “Airport Lounge” — Kevin MacLeod (incompetech.com), licensed under CC BY 4.0.