It is known that red muscle fibres

It is known that red muscle fibres in animals can work for longer periods of time continuously. How
is this possible?

Red or dark muscles store myoglobin and hence, oxygen for meeting the gap between supply and consumption during continuous activity. Therefore, these muscles can continuously work and respire aerobically for long periods. High proportion of these muscles allow athletes to participate
in long duration events like cycling, swimming and distance running, etc.