If you're looking to improve your core muscles and get a great full-body workout at the same time, kettlebells are a fantastic option. You don't need to spend a fortune on equipment either, because a single kettlebell is all you need to get started.
I highly recommend the Amazon Basics Cast Iron Kettlebell—it's a really well-made weight that I use myself. The 10 and 15lb versions are ideal for beginners and currently have 15% off the usual price making them even better value.
Me and kettlebells go way back, but after a long layoff following injury, I wasn't able to use the heavier kettlebells I already own. So I began looking for lighter versions that wouldn't cost the earth but were still cast iron rather than plastic. After scouring the available options, I decide on an Amazon Basics Cast Iron Kettlebell and have been really impressed. Despite the low price tag, they're made from solid iron with a smooth and durable finish. I've been using mine for months now and it has proved to be really good quality.
My 10kg (22lb) model pictured will probably be a little heavy for most beginners, so I'd recommend lighter weights. In the US, Amazon's kettlebells come in imperial sizes, while in the UK (where I am), they're metric.
The Amazon Basics kettlebell range starts at 10lbs and goes up to 60lbs (6 to 20kg in the UK and Europe), so there are plenty of options whatever your level.
My simple kettlebell routine
Here's my three-move routine that uses straightforward exercises but will give you great results in just a few minutes per day. Go for as many reps (up to 20, or 10 each side) and rounds as you feel comfortable with at first, but aim for three rounds once you get the hang of things.
1. Kettlebell swing
2. Single arm clean and press
3. Goblet squats
Of course, that's not the only routine you can do. You can start with this kettlebell workout for beginners and then graduate on to this full-body kettlebell workout. Or target a body part with this kettlebell workout for arms, or these kettlebell abs exercises.