anaerobic
Muscle color reflects its specialization for aerobic or anaerobic metabolism. Although humans are obligate aerobes , our muscle cells have not given up on ancient pathways which allow them to keep producing ATP quickly when oxygen runs low. The difference is more pronounced in chickens and grouse Figure below , which stand around all day on their legs. For long periods of time, they carry out aerobic respiration in their specialized-for-endurance red muscles. If you are familiar with grouse, you know that these birds flush with great speed over short distances. Such sprinting flight depends on anaerobic respiration in the white cells of breast and wing muscle, allowing rapid production of ATP in low oxygen situations.