Lucy Cheah, 24, is a personal trainer and fitness instructor.

Why do you love your job?

I love going to work with different people, and I love it when clients see they have achieved their fitness goals. Exercise is so important; it makes people feel good about themselves and releases happy hormones. After they finish working out and showering, they are happier and more energetic; they walk out with red cheeks, feeling that everything is just like sunshine.

What sort of things do you have to do?

I teach group classes in step aerobics, body pump and body combat, and private one-on-one sessions too. Clients come in with their own fitness objectives for a consultation. I design an exercise programme tailored for them, taking injuries and special conditions into account. Sometimes people come in with an unrealistic image of what they want to look like. I try to meet them halfway, educating them so that they become more confident and aware of how amazing and capable the body is - not just its shape.

Is there any advice you'd give someone with their eye on your job?

You need to be properly qualified, with a diploma in first aid. Being experienced and fit is not enough. Clients expect you to have theoretical knowledge. It's more than just telling people to do push-ups - you need to explain why the exercise works, and be flexible in how you convey that message. People may understand better if you physically show them how to do something, instead of just telling them. You need to be able to spot and correct any muscle imbalances, to improve their technique.

What sort of skills should a good personal trainer have?

Personality counts for a lot. You need to be a good listener who's able to counsel people like a friend, giving them advice on nutrition and lifestyle as well as exercise. Clients expect you to motivate them, and to work as hard as they do. People are never satisfied with their bodies - often you have to tell them not to be too harsh on themselves.

How's the salary and career progression?

Once you are qualified and registered as a fitness instructor or personal trainer with the Register of Exercise Professionals, you can start to build up a client base. You can work in a gym, teaching classes and giving personal training sessions. Or you can get in your car and visit your clients for private lessons.

As a freelance personal trainer, you can earn between £30 and £100 an hour. If you work as an instructor in a gym, salaries start at £13,000 to £16,000 per year, plus commission - although that depends on the gym and your level of experience.