Flexibility and Mobility is the most underused, underdeveloped and under-trained aspect of training and fighting.
Lack of it affects everything. Your speed, power, movement. You will get tapped easier due to lack of full range of movement. You can't kick as high, kick as fast or generate the full power in your strikes.
Stiffness is a huge disadvantage and physical weakness.
You have to stretch and work on your mobility. But that's something most don't want to do. They don't want to spend the time to develop it and then maintain it.
Do not skip the essential part that's going to make everything else better.
Get the full 10-min flexibility and mobility session I do every time I train.
AlexandrovichUnleashed.com