How do you keep fit?
I try to run for half an hour a day, longer at weekends. I also play netball in a staff team and I've taken up belly-dancing, which is great exercise as well as great fun.
What got you started?
I couldn't run more than five minutes without getting out of breath, so last year I decided to do something about it. A friend who was a keen runner suggested I give it a try. I entered a 10km race, and worked to a training plan. That really got me motivated.
How do you make time?
6With difficulty. I like to run each morning, so it's mostly a case of setting the alarm clock a bit earlier. That's fine at this time of year but hard in the winter when it's cold and dark.
Have you felt the benefits?
Absolutely. I'm less stressed, and I sleep better at night. I also feel sharper during the day, with none of those low-energy moments. And the running has improved my netball.
I 'm training to run the Berlin marathon this autumn, so I've lots of hard work ahead of me. Every Sunday I'm supposed to run for 10 minutes more than the previous week. It's a daunting prospect, but I like a challenge.
How active are your colleagues?
Very. The men play five-a-side after school every Friday, and our staff netball team has been doing well in the local leagues. I've even persuaded some other teachers to come along to belly-dancing.
If you start exercising, you'll probably find you eat more. Don't worry - it's natural.
Kalea Haran, 26, teaches business studies at Harris city technology college, London borough of Croydon