By Amy Lawrenson
Every day for years a new CrossFit WOD (workout of the day) has been posted online; these workouts are always varied strength and condition focused, high intensity and short (we’ve championed express workouts before).

So, yesterday in the pouring rain I made my way to a central London park to take part in Reebok’s The Sport Of Fitness Has Arrived campaign to launch its new Cross Fit workouts and Boxes (Reebok’s name for CrossFit gyms).

To really get an idea of what it's all about I did a WOD with the Reebok Ambassadors Jack Osbourne and Christine Bleakly in a timed CrossFit workout. The WOD consisted of 20 burpees, 15 sit-ups, 15 press-ups, 15 squats, 12 sit-ups, 12 press-ups, 12 squats, 9 sit-ups, 9 press-ups, 9 squats, then 20 more burpees. It took me around 7 minutes and I was really out of breath!

‘CrossFit is a shorter, more intense workout and you really feel like you’ve worked your whole body,’ Christine told me.

So I know what you’re thinking - seven minutes, that’s nothing! I work out four times a week, so I’m not exactly out of shape but today I am in so much pain, almost as much as the day after I ran my last half marathon. The great thing about CrossFit is that WODs can be done at home, or at Cross Fit Boxes which are rolling out nationwide, and they don’t take all that much time. Also, unlike most gyms you workout all together and there is a true sense of team work.

‘I don’t particularly enjoy working out on my own, which is why CrossFit works perfectly for me’, said Jack Osbourne. ‘There’s lots of camaraderie and competiveness but when you work out as a team you really push and support each other to achieve your fullest potential.’

But can short, sharp workouts really make a difference? I’m going to be investigating the benefits of Cross Fit and will be putting it to the test, plus I’m going to find out more about the Paleo diet CrossFit-ters embrace. Click here to see out how I got on and to find out how you can get involved...

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For more information in the meantime visit reebok.com/fitness