I tried the 6-12-25 workout method for building strength with a single kettlebell — here's what happened

Woman holding a kettlebell on her right shoulder against a grey backdrop wearing white crop top
(Image credit: Shutterstock)

Always on the hunt to make my muscle building efforts more efficient, I was feeling excited when I recently stumbled across the 6-12-25 workout method. Well, until I found out what it entails. 

The 6-12-25 method is a bodybuilding training routine where you perform three sets of different exercises for the same muscle group: 6 reps of a heavy compound movement, 12 reps of a moderate weight exercise, and 25 reps of a light isolation exercise to maximize muscle growth.

With isolation and compound moves both offering muscle-building benefits and complementing each other, I knew I was in for a solid workout. Most people would probably suggest using the 6-12-25 method in a gym setting so you can use a mix of equipment for each section of the workout structure.

For example, the barbell is a good tool for performing compound moves with, dumbbells provide a selection of weights for the moderate weight exercises and machines are good for performing controlled lighter isolation exercises with. 

However, I've had a busier week than anticipated and with no time to get to the gym, I decided to try the 6-12-25 method at home using one of the best kettlebells for the full routine. Note, I train with an adjustable kettlebell at home which meant I was able to work with lighter and heavier weights for this workout.

Here's what happened when I tried the 6-12-25 method at home.

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What did my 6-12-25 workout look like?

Focusing on my chest muscles, here's what my workout looked like:

  • Exercise 1: Kettlebell Push Press (6 reps — heavy compound exercise)
  • Exercise 2: Kettlebell Floor Press (12 reps — moderate compound exercise)
  • Exercise 3: Lying Down Kettlebell Flyes (25 reps — light isolation exercise)
  • Repeat three times over

I didn't allow myself any rests between each exercise but I did give myself a one minute rest period between each set. I also spent five minutes after the workout stretching my chest and upper body to help with my recovery and avoid any post-workout stiffness.

I went too easy on the first round

I like a challenge, but I'd been warned that the 6-12-25 method isn't for the faint-hearted. It turns out I took this a bit too seriously.

I kept the weight very manageable for the first section of the method, which involves six reps of a heavy compound exercise. In my case, this was an overhead press, done on each side of my body with my trusty kettlebell.

As soon as I moved on to the kettlebell floor press, I realized I wasn't using enough weight to feel challenged by the workout. Sometimes I do the opposite when I train at the gym, picking a weight that's too heavy for me because I don't want people to judge the weight I'm working with.

While, it was nice not feeling this pressure while doing the workout at home, the 6-12-25 method sets out to exhaust the target muscle group so I needed to increase the workload to get that chest pump going.

a woman performing a kettlebell press on the floor

(Image credit: Shutterstock)

The 25 isolation exercises were tough

I felt strongest during the the six and 12 rep sections of the workout but when it came to keeping the form and effort up during 25 reps of kettlebell flyes on the floor, the chest burn was burning.

This was to be expected. Isolation exercises can feel harder than compound exercises because they target a single muscle group, putting all the stress and workload on that specific muscle without the assistance of other muscles. In the other two exercises, I had other muscles supporting my chest during the moves.

Although I was working with lighter weights, my muscles were fatigued from the earlier sections of the routine and by the end of the 25 reps I needed the break to recuperate before the next set. However, I liked feeling like I was getting a solid chest pump and I liked the efficiency of the workout.

The 6-12-25 method is extremely versatile

I can see why doing the 6-12-25 method at the gym will be more favorable to many as it offers a wide range of weights and machines, allowing you to easily adjust the load for different rep ranges (6, 12, and 25 reps) and in some instances target the muscle groups more effectively.

That being said, I was pretty impressed at how effective using a kettlebell at home was. Since I was using an adjustable kettlebell I had the scope to implement progressive overload into my future 6-12-25 routines, which is essential for muscle growth and strength improvements. 

Plus, the 6-12-25 method is one you can apply to different muscle groups to help build strength, muscle mass, and endurance all over.

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Jessica Downey
Fitness Writer

Jessica has been a fitness writer at Tom’s Guide since 2023, bringing three years of experience writing about health, fitness, and the great outdoors. Her passion for exercise began during her childhood, where she spent weekends hiking and competing in local athletics club events. After earning a master’s degree in journalism from Cardiff University, Jessica found the perfect way to combine her love of storytelling and fitness into a career.

Jessica is passionate about testing fitness gear and tech, using her reviews to help readers make informed buying decisions. She ran her first marathon in April 2024, finishing it in 3 hours and 48 minutes. Through her training, she’s developed a deep understanding of what it takes to grow as a runner, from effective workouts and recovery techniques to selecting the right gear for every challenge.

When she’s not at her desk, Jessica enjoys spending time in the kitchen crafting new recipes, braving cold water swims and hiking.