How much of my personal statement should I leave for extra-curricular activities?

A small paragraph of your personal statement should include any extra-curricular activities you would like to mention. This might amount to about 10% of your overall statement. However it's important that most of your statement should be academic, or to do with your work experience. For some universities it is more important that extra-curricular activities are present than others, but it is also important to present yourself as a rounded person since medicine is a social profession as well as an academic one. It is also important to remember that if you cannot fit everything you wanted to into your statement then it is possible to request some things to be put into your teacher's reference, such as positions of authority you may have held. Therefore you can prioritise using the short space you have for reflection on your work experience, a vital part of a medical school application.