Failure to prepare the hip flexors for 90 minutes and your performance could be one to forget.
More after the break
To the layman the hips serve no significant purpose to the movements of football, but this couldn't be further from the truth.
In actual fact, they play a crucial role in a number of actions relevant to football.
To make sure you're able to kick harder and run faster than your opponents, you need to get your hip flexors ready for the activities ahead.
A simple workout with a foam roller is the ideal place to start, as Erith explains.
"The hip flexors is an area that is notoriously tight with footballers because they're so heavily used," he told FFT.
"In the mornings we work with a foam roller. This helps the player loosen up, get rid of any tightness from yesterday's training and get them mobile for the main session."
In this video Erith takes Micah Richards through a typical pre-activation session using a foam roller at City's training ground. Watch and learn.
Micah is an ambassador for If U Care Share, a charity that encourages young people to discuss their problems: www.ifucareshare.co.uk
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Switch on your glutes for 90 minutes: Part one
Switch on your glutes for 90 minutes: Part two
Fire up your hips for action: Part two