Liverpool defender Jamie Carragher is keen to play for as long as he can.
He is eager to carry on playing as long as possible and he pays close attention to his personal fitness.
"You get more mature and have an understanding of how your body works and it is a short career so you have to maximise it as much as possible," he said.
"Fitness was drummed into me when I was growing up and as you get older that becomes more apparent and you have to look after yourself.
"Once you reach 30 people start questioning your fitness or whether you have lost your ability and teams start looking for younger players so you have to look at the fitness side of it."