The first kettlebell workshop I ever attended was taught by Mike Mahler. I had probably held a kettlebell twice in my life. I hear about his workshop, I think "awesome", and off I go. The deal was that if you brought your own kettlebell with you, you got a copy of his DVD. So I take a 4kg kettlebell. It’s the smallest one they make…but hey, I was new and I thought it was the right size for me. Well, I proceeded to get teased all day about my “baby rattle”. By the end of the day, Mike and his assistants had literally bullied and scared me into getting a 12kg above my head…something that I considered impossible at the time. I was barely able to drive home, I hurt everywhere for a week, but I learned two important lessons:

1. I am much tougher than I thought; and

2. If you already work out, don't buy the smallest kettlebell.

So, what size kettlebell is right for you? First of all, understand that no system is foolproof and everyone is different. The information below is a generalization based on my experience with many clients but you could be the exception, meaning: if your intuition tells you something different to what you read below, go with your gut.

Before we start, a technical side note.  Since kettlebells are from Russia, they are always listed in kilograms (kg) and not pounds (lbs).  So, to save you running to get your calculator or a Google search, here are the kettlebell sizes translated into pounds for those of us that are metrically impaired:

4kg = 9lbs  /  8kg = 18lbs  /  12kg = 26lbs  /  16kg = 35lbs

I know that may not seem like a lot of weight, but don’t let the numbers deceive you. Kettlebell training involves constant movement with a lot of repetitions; you will be amazed at how heavy they can feel after just a few minutes. So, use the following guidelines to pick the right size for you:

For Women:

If you have never worked out in your life, have trouble carrying a gallon of water 20 yards, and are skinny and underweight, you should probably start with the 4kg.

If you don't work out at all but are moderately to seriously overweight, trust me when I tell you: you are stronger than you think you are. The 8kg is probably a better choice for you.

If you work out "a bit" and can lift 15lbs above your head with one hand a couple of times, get the 8kg. You might have to work up to doing all of the reps in my workouts, but it's better to have a slightly-too-heavy kettlebell than one that's way too light.

If you work out quite a lot and can get 25 pounds above your head a number of times, (and your shoulders are very strong and stable with no previous shoulder injuries) get the 12kg. Again, you might have to work up to doing all the reps in my workouts.

If you are really strong, have plenty of experience with kettlebells and your cardio is great, get the 16kg, but be warned that this is not a beginner or intermediate weight for women. Swinging 35lbs around and above your head is serious business.

For Men: (don't let your testosterone get the best of you)

If you have never worked out in your life, have trouble carrying a gallon of water 20 yards, and are skinny and underweight, you should probably start with the 8kg.

If you don't work out at all but are moderately to seriously overweight, you are stronger than you think you are, and the 12kg is probably a better choice for you.

If you work out "a bit" and can lift 30lbs above your head with one hand a few times, get the 16kg. You might have to work up to doing all of the reps in my workouts, but it's better to have a slightly-too-heavy kettlebell than one that's way too light.

If you work out quite a lot and can get 35 pounds above your head a number of times, (and your shoulders are very strong and stable with no previous shoulder injuries) get the 16kg or the 20kg.

And if you are really strong, have plenty of experience with kettlebells and your cardio is great, get the 20kg or heavier, but be warned that these are not beginner or intermediate weights for men. Swinging 44lbs around and above your head is serious business.

You might even decide to buy two sizes: an 8kg and a 12kg are a great beginner pair for most women. Men could start with the 16kg and 20kg. But again, I urge you to go with your gut. If you would be really nervous lifting the 12kg over your head, go with the 8kg and build your confidence first. All of these size kettlebells can be purchased on my website for a discounted price. Hopefully you’ll have a similar experience to mine, and find that you're tougher than you think you are!