My mat will need replacing before long as it's starting to wear down quite a lot. It was just a cheapie one from Sports Direct that I've had for years. In particular, I'm looking for a slightly thicker one as we have wooden flooring and at the ripe old age of 34, my knees are starting to play up 
Any recommendations for a mat? Ideally from the UK and can afford up to £30, but £40 at a push if it's worth it.