Crossfit has to be one of the absolute best exercise plans out there because it exercises so many different muscle groups and is great for both strength training and aerobic exercise. Only go to a legit crossfit trainer who has been certified though, there are quite a few fake ones out there.
I am a very athletic guy and been a swimmer my whole life. Cross Fit is NO joke and pushed me to the edge of my cardio and strength work-outs. I went to about 5 classes (my buddy owns a franchise) and it was straight military boot camp. Although they do have classes for beginners and more advanced. I HIGHLY recommend these classes and you will notice results. I got to the gym 5 days a week and after 1 of these classes I had to take 3 days off cause my body was worked very hard and needed rest... 5 out of 5 stars.
Novices try to do everything the trainer says within the time restriction, but that leads to bad form and injuries. Avoid that. Take your time, do things well and you will not have to worry!
I use them everyday when I go jogging everyday.It makes me be focus on my exercise time & is great to use it everywhere that I go to my exercise places