If you compete and train in a martial art, then both strength & flexibility are valuable physical assets that you will no doubt want to build & develop.
Create a more functional workout and kill 2 birds with 1 proverbial stone with these exercises.
Remember to warm up and build up your strength & flexibility gradually. You can definitely injure yourself doing some of these exercises:
Great for shoulder strength and hip mobility.
Can place stress on the lower back.
Weighted Downward Dog
Hindu Press Ups