Webinars are great (more work) but I’d do a free teleconference where you just “talk” and people can hear and ask questions (you can also mute them out which I do). I have them submit questions prior to the teleconference.
So, something like this “7 Secrets to Stay Fit During the Holidays” Everyone wants to know this right? 🙂
You can promote through your social media, email contacts, gym contacts and let them know they can tune in or get a FREE replay.
I use http://www.freeconference.com/ Totally free unless you want the recording $6 for replay sent to your attendees.
I had over 130 people sign up for my teleconference and I use it now for other promotional ads and giveaways in my email newsletters etc.
Hope this helps and good luck on your call!