I admit, it doesn't look pretty. After trying out a few different weights - and putting my back out in the process - I'm at the till paying £20 for what looks like a great big ball of iron. But that's exactly what a kettlebell is - a cast iron canonball with a handle sticking out of the top. It looks faintly medieval - the sort of thing that would be kept in a dungeon alongside a poleaxe and iron maiden. But for all its ugliness, this is a piece of kit that promises great results for a person's lower back, legs and shoulders. It also strengthens the body's 'core,' in case you were getting particularly concerned about the state of that.

I've chosen a 3kg weight, which is frankly a baby compared to some of the other boulders on offer. It's recommended that you don't get carried away in choosing your first kettlebell, and pick a weight that feels challenging but manageable. Anything too heavy will not only be a pain in the neck to get home (literally) but will put you at serious risk of injury, and that's just counter-productive. Be patient, and work your way up to a larger weight gradually.

If this is your first time with a kettlebell, and you have no intention of joining a class, I'd really recommend cruising around YouTube for some video pointers. Not only will the awful ones give you a few laughs, but vids such as this one will give you some great ideas on how to put together an effective kettlebell workout. I also find that it helps to see the moves in action so you can compare how the professionals are doing it with your own limp wristed efforts. And then hastily correct your form, obviously. If you prefer to get your kicks from analysing diagrams, there are also plenty of how to books you can buy on Amazon.

I've been using my kettlebell for around a fortnight now, and one of the first things I noticed was how different it feels to working out with a standard dumbbell. This is because the kettlebell's asymmetrical shape makes it an 'unstable' object, and when used correctly it puts the body 'off balance,' triggering all 38 core muscles. Spending just 20 minutes a day blitzing through basic moves such as the 'swing,' 'snatch,' and 'clean and press' has earned me the reappearance of my shoulder blades and a pretty toned pair of arms, as well as taking my muscular endurance up a notch. It's also - dare I say it - quite fun. There's something a bit primal about swinging around a cannonball in the privacy of your own bedroom, and there's no denying sticking with it can get you quick results. Just steer clear of low-hanging fixtures....

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