Sorry but No. That would be "providing a service" As a recreational pilot you can only fly for "recreation".
NOW if you film the practice for your own enjoyment then you are fine.
In other words( as far as anyone asking is concerned) you are NOT filming for anyone but yourself.
Its all about the "Intent" of your flight. If you intend to fly your Drone for the purpose of filming practice for the coach then you cannot do that without a part 107. (you cannot provide a service. Even for free.)
If you Intend to fly your Drone to video practice to watch yourself then you are fine. Maybe invite the coach to come see some of your "Personal" Videos. I know it sounds funny but thats kinda how the rules work. Always think of intent.