I'm a global ambassador for the World Wildlife Fund and United for Wildlife and I am also a Unicef UK ambassador. It's important to me to support charities. I never want to take my wealth for granted.

I wouldn't say I'm a spender in the sense that I'm going out on huge spending sprees. However, to be able to function at the top of your game on the professional tennis circuit often requires an element of frequent spending.

Boxing, mixed martial arts and tennis are the hardest sports to train for.

My fitness trainer's English, my physio's English, some of my friends are English. I don't have a problem with English people at all.

I first had money for investment just at the time of the 2008 crisis and shares have been highly volatile since then. So I do have shares in my pension but I have tended to invest in specific projects that include property and private companies that have been very well researched by my advisers.

Give it everything you've got. Leave nothing out there.

Contrary to my image, I do have a sense of humour.