Also Anytime Fitness operates the same way as Natalie described for Snap Fitness. In your case, you will need to make sure that there is always a trainer at the gym because of the customers you are targeting. Since you are dealing with retirees, keep in mind their age and their health issues or limitations they might be having. As Susan stated, how many retirees or senior citizens will be using the gym at those hours? Is it worth it to have it open and staffed 24/7 if the number of the people working out at those times doesn’t support such decision? A surveillance camera can help, but it’s not a substitute or as efficient as an onsite personnel.
As far are your trainers keeping their certification credentials, they need to keep up with the requirements of continuing education from their organization. If not, then they will lose them. You can also check on them to make sure they are doing so.