PRACTICE IS AS IMPORTANT on the flute as on any instrument. As with all wind instruments, the length of time spent practising depends very much on the condition of the embouchure and how long the lips and lungs can keep going.
Though professional players get used to playing for long periods of time, it is not possible to continue playing a wind or brass instrument for as long as, say, a keyboard instrument. Many older players find that they can no longer physically achieve what they could when younger.
The instrument itself also needs to be warmed up to be in the best playing condition – as Anna Pyne explains.