Thanks guys, been working hard for it
Now I need some help (for a change), now having access to a pullup bar I decided to add some ab exercise to the usual situps and dragonflags. I want to do some of those exercise where you hang from the bar and kick your legs up and touch the bar with your feet, twisting your legs in a circle etc. Now I have no idea what to call these so excuse my lack of knowledge in calisthenics stuff.
Now as soon as I started doing these, no stretching obviously, going rambo mode for a change

while supposedly I was working my abs, my quads started pulling really badly to the point that I had to stop. This is where I need your help, are there any tips like should I stretch (lol, obviously), should I bend my legs instead of keeping them straight? or any other technique that might help.