There are many sub-niches under health and fitness. This will all depend on you which one you want to target: Weightlifting Aerobics Hair Loss Skin Care Weight Loss Back and neck pain Joint pain Yoga Cycling Running Anti-aging Eating habits Eating disorders Health issues - each by subject - there are so many to list. The list can go on and on. You just need to figure out which one you want to target and build your site around this subject only. Furthermore, you can break these down into other sub-categories to add these to your website or blog. There are different types of dance people use for health. Many gyms offer certain types of exercise dance classes that a person can join. You have different types of yoga. Right now people across Europe are getting into **** Yoga. Yes, this sounds very funny but they will do yoga holding a glass of ****. I have no idea who invented this, but for some reason, it is really taking off.