I would base this decision on
How much time will it take start to finish for you?
How many participants?
What level of training will you be doing?
Do they all have the same fitness goals?
Are you teaching a specific task to enhance performance?
What do you charge for group training?
Can you offer an incentive: 5 classes for $100 10 for $185? per person?
Hockey players are generally really fit under all of that gear!!