With all this traveling, bad weather, shitty trains I got sick so I can't train outside at the moment. So for all fellas out here who can't leave your homes right now or just don't want to, I wanna show you how one can easily build muscle at home. One of my favorite things in bodyweight training are so called animal movements(bear crawls, duck walks, etc.). They are proven strength builders and widely used by martial artists and American football players as a part of their training routines.
So here is my personal calisthenics routine for muscle growth consisting of only two exercises: duck walks and crab walks. All you need to do is just go long distances 5 days a week. In each exercise just walk back and forth. In each workout you should cover distance that you can't cover in one set, so you just keep walking until fatigued, then stop, take some rest and continue. Move and rest until you've covered all distance. That's it. Those exercise are, as one fitness guru once called them, inefficient movement so it engages lots of muscle fibers and stimulates body to primarily burn fat for energy. Paraphrasing a great coach Ross Enamait "Complete challenging tasks and you will grow". Oh yeah and don't forget to eat well (without building material there's no muscle)!
To your success!