Paired with its companion app, JaxJox’s smart kettlebell offers coaching smarts as well as interchangeable weights.

Another space-saving selectable kettlebell that’s great if you’re tight on room, the JaxJox KettlebellConnect 2.0 works much the same as the Bowflex Selecttech 840, with a hard plastic shell that houses a set of interchangeable weight plates. But unlike most of the best kettlebells, this one also has a brain that brings your swing training to life. So it’s a kettlebell and a coach.   

Men’s Fitness verdict

With on-demand content, coaching and smart tracking, JaxJox is revolutionising kettlebell workouts. These smarts don’t come cheap though.
  • Decent top weight
  • Counts reps, sets and weight
  • Bulky with a big footprint
  • Hardware and premium app are pricey

How we test the best adjustable kettlebells

Our testers Kieran Alger and Leon Poultney are experienced product reviewers of all manner of fitness kit. They tested these kettlebells at various weights and through a range of exercises at high rep ranges to see how they handle. They marked each one for grip, comfort (and weight range for the adjustable options) and gave an overall score that takes build quality, performance and price into consideration.

JaxJox KettlebellConnect 2.0 features

The JaxJox KettlebellConnect 2.0 packs motion sensors inside that not only track reps, sets and power, but let you follow complete drill-by-drill workouts on your smartphone, or join on-demand coach-led classes, tracking stats as you go. You’ll have to pay a Peloton-style premium to access all of them, though. Currently that’s $24.99 per month.

It will also spit out a FitnessIQ score, which is essentially just a number that goes up the more you train. However, it’s a good way to benchmark your weekly progress and incentivize your kettlebell home workouts

The weight options are slightly heavier than the Bowflex across the range. They shift up initially in 3kg and then 2.5kg increments and include six weights: 5.5, 8.5, 11, 13.5, 16.5 and 19kg. The automatic switching at the press of a button is a shade easier than the Bowflex, too. 

Like the Bowflex, the JaxJox KettlebellConnect 2.0 is notably bulky. As a result, I felt that sometimes it was more awkward to use and doesn’t feel as natural as your regular kettlebell alternatives. That may be a trade-off worth making for the connected smarts and space-saving gains, but if you’re a beginner the heft and shape might work against you. On the plus side, the handle is wide enough for double-handed drills and offers a good non-slip grip. 

The other thing to note is that the JaxJox needs power for the selection and smart training features, so you need to stow it near a plug. You will get around 14 hours of training time on a single charge, though. 

Weight range5.5kg-19kg (12lbs-42lbs)
Number of weights6
FeaturesAutomatic weight switching; Coaching app (subscription-based)