You can build both size and strength from kettlebells, but you’re going to have to use some heavy weight to get there!
There are three different training cycles within the “Strong!” program.
Most men do well with 53lb kettlebells. You can keep them in the trunk of your car and you can get a workout wherever you’re at; in a park, in the parking lot or in your yard. But make no mistake: Kettlebells can be a huge ally in the quest for mass. Also if you can bench press 225 or more start with the 53s. So to build muscle with kettlebells you need to ensure that every set challenges you between 7 – 15 reps.
If not then get the 35s. Program. Basically if you can do 50 pushups, 10 pull-ups, and 100 bodyweight squats, start with the 53lb kettlebells. The premise of Kettlebell STRONG! The Strong! is that you can get brutally strong with one pair of kettlebells by repeatedly performing one compound exercise well—the Clean and Press.. The way most people are using them in the gym is as a lightweight way to break a serious sweat, and nothing else. Never train to failure or you …
This process is detailed in the multi-phase, multi-mechanism “Strong!” program. Imagine taking a set of kettlebells into your gym, farmers walking them past reception and doing a killer workout while everyone else is struggling away on the elliptical. You will burn a lot of calories, shed a lot of fat, and develop a well-toned physique from kettlebell work. While some may argue that kettlebells put you at a mechanical disadvantage (which is what forces you to use less weight), it really all boils down to tension.
However, if you are out of shape and just getting into training, start off with a 35lb kettlebells. If you don't associate kettlebell exercises with building muscle, well, that's understandable. Trust me, if you’re in the 10-53 lb kettlebell range like most people, then you’re never going to be the next Arnold! If the weight is too heavy then you will build strength and tire out before 7 reps and if the weight is too light you will fly past 15 reps and build endurance instead. With kettlebells, you can decrease the training load by up to 75% and still make significant progress in strength, power, and body composition goals.