you might have stumbled over something that's called calisthenics and thought Wow that's impressive! and you may wonder, what's better for building muscle? the answer is it depends. let's say your 12-14 then it's not recommended to start weightlifting, so calisthenics would be a great alternative for growing some muscle and getting in shape. calisthenics is great for boosting testosterone which is essential to building muscle!, but let's say you're way past 14, then i would definitely recommend weight lifting or combining them, because if you just want to put on that muscle and get jacked, then you will have the weight training to put on that muscle mass, and the calisthenics as more high intensity training which burns more calories and will help you shred that fat.