But the arrival of the dockless bike-share model was received mostly with praise and excitement in a city that has embraced biking as a mode of transportation. Some biking aficionados said they hope the companies will indeed bring more bikes to underserved communities of the District, including the Northeast and Southeast quadrants.
It sounds super-gross but please try to imagine it: Red muscles, pink muscles, and white muscles. The red muscles are red because they contain lots of myoglobin: a protein that binds iron and oxygen. Your blood has a similar protein called hemoglobin which binds iron and oxygen.
Skeletal muscles are divided into two muscle fiber types: Slow-twitch (type I) muscle fibers contract more slowly and rely on aerobic metabolism. They contain large amounts of mitochondria and myoglobin, an oxygen-storage molecule. The reddish color of myoglobin is why these fibers may be referred to as red fibers.