CURLY HAIR HELP

So, I have curly/wavy (more curly than wavy) hair. I use the best products for curly hair and the no poo method. The problem is that I do gymnastics. When I go to gymnastics I always wear my hair in a bun. I obviously can not do a loose bun because it will fall out. When I come home from practice and take my hair out, my curls are all matted to my head and flattened and look really bad. I know I could wear it in a ponytail but i am so used to wearing it in a bun that wearing it in a ponytail gets annoying. Any comments or suggestions would be great! :)