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.
To understand twitch more, you can take a look at fast and slow twitch muscles. Type I slow twitch skeletal muscles are usually bright red, filled with myoglobin, have tons of mitochondria, and work by utilizing O2 to aerobically make energy (ATP) for contraction. These fibers make and split ATP at a slow rate.