The 5ft 5in midfielder knows he needs to build himself up to handle the rigours of the Premier League.
"I have been working a lot in the gym after normal training to build myself up and get stronger," Anita told the Sunday Sun.
"I am doing this so I can play more games for Newcastle and play well in them. I have started doing a lot of running on my own as well because my physical condition needs to improve because I am operating at a higher level now.
"I have settled in a little bit. I say that because on the park I can play better. I am hard on myself. This football in England is very different to what we have in Holland.
"There is a lot more running, which means I have to keep improving myself in training because it's so important to be able to cope with the demands"