Personally, I use IF to help control my bodyweight and fat %. But lots of clients and athletes often ask me how on earth you can do this and still train... Well, it's all about working out what works for you and your body around your training plan. 

For example, the 5:2 principle doesn't work well for me as I can't train hard on the off days. However, a 14-16hr daily fast does... I'll try to do my cardio work when fasted and then do any HIIT or S&C sessions later in the day when I'm fuelled. Where for some people, who have a very busy work schedule, the 5:2 principle is thrown in on busy day's where training just isn't possible and it works well.

It can work great for all types of clients and athletes, however, you need to get it right for you.

Have a read of this article by Training Peaks and if you'd like to discuss how to make it work for you then just get in touch.