Usually I get up between 6am and 6.30am and have something healthy for breakfast like poached eggs on brown-bread toast with no butter. I also make sure I have all my vitamin and mineral supplements with some organic orange juice.
My first session of the day is at 8am and it's usually with Geri Halliwell for two hours of cardiovascular fitness and weight training. That body did not come just from yoga.
My training sessions could be anywhere, so I'll drive to meet my second client for about 10am and eat a snack, such as fruit, on the way. I might do a one-hour session with a client in Hyde Park and then drive to Regent's Park for another hour's training at 11.30am. If we're outside, I'll work out alongside the client, but some people have their own gyms, in which case I would mostly direct.
At about 12.30pm I'll break for lunch and meet up with some other trainer friends. We'll have lunch somewhere nice like the Blue Bird Café on the King's Road. We talk about our clients - who's losing weight and who isn't; who's working hard; and who keeps cancelling. We all eat meat to get our protein intake.
After that we'll all go together to do our own weights work-outs at the gym for about an hour.
In the afternoons I leave some time to do interviews with the press. I trained Pierce Brosnan, Sophie Marceau, Denise Richards and Halle Berry for the last two Bond movies, so I get quite a lot of media attention. I've also written a fitness book, Commando Challenge, so people want to talk about that. I do about one interview every other day.
Halle Berry didn't need a lot of work to get her body looking the way it did in Die Another Day, but she put a lot of effort in. It's easy working with stars, because they're quite used to having trainers and nutritionists. Working with someone who's unused to exercise or the gym is much more difficult.
During the afternoon I'll talk to my ghostwriter, who's currently working on my second book, Commando Workout. I was a marine for seven years before starting this business, which explains the military theme. Then there might be other meetings to discuss new projects or clients.
By about 5pm I'll be at the Peak gym at the Carlton Tower to train with clients there. I work with a couple of models and various other members. I do about 12 hours' training there a week - it's a convenient location for me and it's got a nice atmosphere with a great view over London. They also do quite good food.
At about 8pm I head home and eat - probably just chicken, vegetables and maybe a protein shake. I then give myself 45 minutes to work on my second book and 45 minutes to answer e-mails from people who've got questions from my first book. I feel bad because I can't answer all the questions, but I only have a certain amount of time. Then it's straight to bed between 10.30pm and 11pm.
Interview by Jessica Gunn
Factfile
The Peak Health Club & Spa, Carlton Tower Hotel, 2 Cadogan Place, London SW1X 9PY
Tel: 020 7235 1234
Full membership fees: £1,970 per year or £522 per quarter (including three personal training sessions a week - not with Waterson)
Cost of one hour's personal training with Waterson: £75-£100
Just a minute...
Tell us a secret
Geri Halliwell's body isn't down to yoga.
What's the best thing about your job?
Seeing people reach their goals.
Who is your favourite celebrity among those you've worked with?
Halle Berry. She was the most fun.
What's the worst thing about your job?
Faking it when I get tired myself. It's awful having to fake enthusiasm for that last exercise session of the day.
What tips do you have for hospitality workers who want to improve their health and physique?
Be balanced. Don't try to do everything at once. Don't try to give up smoking, go on a diet and do more exercise all at the same time. Do one at a time, start with a little exercise and be moderate.