“If you were to stick me in a prison where all I had was a 16kg or 20kg kettlebell, and you told me I would only be let out when I was in the best shape of my life, I could pull it off,” legendary strength coach Dan John confidently tells me. I have every reason to believe him.

“I’ve been lifting weights since 1965, coaching since 1979, I just broke the national record for the clean and jerk in my age group, I’m stronger than anybody you know, and I’m 67,” he adds, by way of a CV. John also invented the goblet squat, which is now a staple move in a host of strength training routines.

But why the kettlebell? This free weight often sits overlooked while gym-goers make a beeline for shiny new machines.

“Because you can stick a kettlebell in the corner of any room in your house and you have a whole gym,” John says. “You can get your cardio work done, your mobility work done, your flexibility work done and increase your strength. It is a one-stop shop for training.”

Once you’ve been won over by the kettlebell’s many benefits, the only thing standing between you and “the best shape of your life” is knowing how to use it effectively. Luckily, John is here to help with that too.

Below, he shares his three founding principles for successful kettlebell training, and a three-move workout which applies each of them to impressive effect.

Rule one: the body is one piece

You might be familiar with body part splits or bro splits – a training method which involves choosing a muscle group or two to target on different days of the week. But to John, this way of working out has another name: “Frankenstein’s monster training”.

“This is a horrible way for 99.99 per cent of your readers to train,” he says. “The body is one piece. Walking does wonders for the spinal column, and the eyes and the vestibular system; it’s not just for your feet, ankles, legs or butt, it’s a whole-body movement. Getting away from that way of thinking is so much healthier for most people.”

Putting this into practice could look like two or three full-body workouts (like the one below) per week.

“As you learn more moves, you can also figure out that one day a week is a mobility day, one or two days a week are ‘get sweaty’ days, one or two days a week are ‘get strong’ days, and the piece of equipment remains the same,” says John.

Read more: This is how to perform a deadlift correctly, according to a strength expert

Rule two: don’t neglect your mobility

Mobility is often conflated with stretching and other flexibility practices nowadays. But, by definition, it simply means the ability to move freely.

For a successful strength training session, you need to access certain positions while supporting extra weight, with the bottom of a squat and a strong overhead position (where your arms are extended above you) paramount among them.

To help with this, John recommends a straightforward daily practice: spend 30 seconds hanging from a pull-up bar, then 30 seconds sitting in the bottom of a goblet squat. This will improve your mobility and prepare your body for the exercises ahead.

Read more: I tried Alex Yee’s running workout and it humbled me in just 40 minutes

Rule three: foundational exercises for beginners

You can build a comprehensive kettlebell training programme on just three foundational exercises; the kettlebell swing, the goblet squat and the press-up (John usually lists the Turkish get-up in place of the press-up, but omits it from this beginners’ guide due to its complexity).

“We call those the hardstyle three,” he says. “With these, we can challenge most people in a training programme.”

But how many should you do? While some factions of social media push a “more is better” message for exercise, John uses the concept of the minimum effective dose, or MED for short. For these three exercises, those doses are 75-125 kettlebell swings, 15-25 goblet squats and 15-25 press-ups per workout. This should provide “a routine that will provide fitness, longevity, health and performance,” he says.

As for the weight you should be lifting, John reckons a 20kg kettlebell will adequately challenge most men, while 10kg is a good choice for most women. However, this can vary on a case-by-case basis.

“Many people will need to go heavier or lighter depending on age, experience, health and goals,” John adds.

Read more: Rucking is the fitness trend that’s here to stay – here’s why you should try it

How to do Dan John’s three-move kettlebell workout

Now you’ve learned the fundamentals of successful kettlebell training, it’s time to put your newfound knowledge into action. To do that, John prescribes “the humane burpee” – a full-body workout which uses all three of the essential kettlebell exercises. Here’s how to do it.

John recommends focussing on using good form for each exercise – achieving full squat depth, maintaining whole-body tension during the press-ups, drawing power from the hips for the kettlebell swings, and so on. But that doesn’t mean you should slow your pace drastically and sacrifice all intensity. This workout is designed to get you sweaty and strong, so you should try to flow smoothly through the moves.

“If you have to stop, you stop, but your goal is to do it with minimal breaks,” he says. “The only time we would [want to] rest is iduring the transition from the press-up back up to the swing.”

So there you have it, a full body session using a single piece of affordable equipment and three rules for great form and development. If time or your bank balance prevent you from heading to the gym or attending fitness classes, you can flex just as hard with the help of a humble kettlebell from the comfort of your living room.

Read more: ‘Badass’ Friends star Courteney Cox can do a perfect chin-up at 60 – you can too with these three tips