I was very active at school, but at uni I had new priorities, ever-changing timetables, and it was hard to get into a routine. I got lazy. When I moved home after graduating, I wanted to get fit again, but the gym got boring very quickly. I’d seen CrossFit pop up on Facebook, so I checked it out. Three years later, I’m there five times a week.

Every time you go to the CrossFit gym (or “box”, as it’s known) you’re doing something different. Classes are an hour long and everybody does the same workout, which has been written up on a whiteboard by the coach. The workout of the day or WOD (CrossFit has its own language, which you pick up fairly quickly) could include any or all of weightlifting, running, rowing or bodyweight squats and pull-ups. They’re all fairly standard movements that you would do in the gym, but the coaches mix it up from day to day.

I go to the 7am class at CrossFit Bath every weekday before work, and it’s normally all the same faces that turn up. It’s very sociable. There’s a wide range of people in our class, of all ages, genders and backgrounds; people you might never otherwise associate with, you get to know really well. You all do the same workout and experience the same pain. In a good way.

The best thing is that everything is measurable. You might not do the same workout for six months, but when it comes round again you can see how you’ve improved. You get competitive, not so much with your peers as with yourself. It’s had a massive impact on my body. I’ve put on muscle mass and become leaner, fitter and stronger.

It’s very addictive. I’m not unusual in devoting so much time to it. My colleagues think I’m crazy, but I find that going before work wakes me up and sets me up for the day. I sit at my desk pretty much all the time, so CrossFit is a perfect way to stay active. It never gets boring.

My weekend workout

Number of sessions per week? Usually five.
Best post-CrossFit breakfast? A recovery shake, porridge, bacon and eggs – I tend to be quite hungry.
Most exhausting move? Wall ball. You throw a medicine ball up to a 10ft target, catch it, squat down and do it again.

Five ways to get started

1 Most CrossFit gyms run taster sessions, where you learn the basics and finish with a workout. They’re really useful, whether you’re a fitness fanatic or haven’t stepped foot in a gym in your life.

2 Don’t try to run before you can walk. The boards showing the workout of the day will have recommended weights for experienced CrossFit goers. If in doubt, consult a coach.

3 In an Amrap (as many reps as possible) workout, you should still focus on form over speed. If you’re doing lots of half-press-ups, or pull-ups where your chin doesn’t get over the bar, you won’t see any improvement in six months’ time.

4 Inappropriate footwear can lead to injuries. Running trainers have thick, spongy soles which are great for cushioning feet over long distances. But if you’re doing a squat or a deadlift, they can make for an unstable base. It’s better to have a flatter sole.

5 Any gym can claim to run CrossFit classes, but not ensure you get the best (and safest) coaching. Find your nearest on the official site.

• Bex Hall, coach and member of Team Reebok UK

Essential kit

From left: Reebok CrossFit Nano 6.0 trainers, £89.95, reebok.com; Rehband Core Line RX knee sleeve, £22.50, kitbox.co; Classic SGF Speed skipping rope, £25, sgfspeedropes.com.

• Do you have a passion for exercise? Send your story to fitness@theguardian.com