ClubPal allows you to create and assign your own groups to members. You can view the groups a members is in on their member page in the Admin area and assign groups by editing their profile.
The main benefit of adding groups to members is that you can then send an email to one or more groups. You could add a Coach group, or even Run Coach. If you then want to email all coaches or run coaches, you can do that by using the Smart Group feature of the compose email tool.
You will also find a Group filter on the Members list page at
Admin > Membership > Members page. You can export all members in this group or use this page to launch the Quick Compose email too.