U.S. track legend Michael Johnson paid a visit to Arsenal's London Colney training ground, with former 200 and 400 meter Olympic champion providing some fitness training for the youngsters.

Some of the Arsenal players regularly visit Johnson's running performance school in Texas, as the Gunners players look to improve their techniques while sprinting, with Ignasi Miquel the latest to reap the benefits.

Arsene Wenger revealed Johnson was not officially a part of the club, but explained the effect going through such a training regime has on the players. "He has no role at the club," Wenger is quoted as saying by the Daily Mirror. "He is a runner. We sometimes co-operate with his school.

"For example, if a player needs to work on some aspects of his physical side, we send them there for preparation. It is a fantastic school, but he is not directly involved with our team.

"This summer it has been Ignasi Miquel and a few youth players. Has he come back faster? Not fast enough to win a gold medal!

"But you have two ways to run quickly - I will teach you now. First, is to do as quickly as possible your movement, but you gain that very quickly, you will not improve that at the age of 18.            

"The second is that, every time you make your movement, to have more power on your push. That is quite logical. If I can run at the same pace but can gain power every time I push, I gain one inch more. I will be quicker if I can repeat the frequency of my movement.

"He (Miquel) gained some power, but it is always very difficult to measure if you are 18 or 19 - even if you do nothing, you become a man and you look more muscular.

"You get an injection of testosterone between 18 and 21, 22, sometimes up to 23. Then you are a real man. Some get it at 19, some at 20-21."

Arsenal take on Olympiakos Wednesday in the Champions League and Wenger will be desperate to get back on winning terms as well as pick up another three points in Europe.