Martial arts is amazing for working out and it's more fun than doing situps all day, try boxing and if that's not your speed I'll add more types of martial arts in another list
Very cool and there's tons of videos on YouTube about boxing
BOXING TRAINING AT HOME FOR BEGINNERS WITHOUT EQUIPMENT
Some basics cause you gotta start somewhere
Basics of Boxing - Training for Beginners at Home
I like to check out a few people to see who I can pick things up from better, it's nice having multiple teachers
How to Box in 4 Minutes | Boxing Training for Beginners
Good to know and practice every day
Boxing 101: Learn the 6 Basic Punches for Beginners
Some motivation
becoming a boxer at home is easy, actually
Cause you have to workout first
10 Minute Beginner Boxing Workout | Good Moves | Well+Good
Good 101 course on boxing
How to Box 101 | Complete Boxing Tutorial for Beginners