It improves libido for sure. It has test boosting properties for sure but isn't proven to work for everyone. It mostly boosts no production and dopamine. Which makes it a feel good herb not much more. With more Nitric Oxide you will get better pumps when working out. Which is a plus.
Exactly what I was about to ask.
Also whenever your coach asks you to do something that you that might sound a little weird you should always question him/her why?
If he can't give a reasonable explanation to why you are doing something/eating something or what ever you should look for another trainer.