You can give them suggestions about different things they can do when they are home or in their free time and it doesn’t look like they are exercising (even though they are great activities). For example take the stairs instead of the elevator, when shoveling snow use a shovel and not a snow blower, when they cut the grass they should use a mower which they have to push manually instead of a self-propelled one, walk more instead of driving, etc.
I hope this helps!
You could also do a seminar on stress reduction techniques, mind/body connections, have local gyms or personal trainers do demo classes to see the different forms of exercise, Getting rest sleep and its relationship to weight gain, environmental toxins, diet myths vs. realties, detoxes: good or bad, have a few local farmers come in (organic is it worth the price?), etc.
Think of all the areas that impact a person’s health. You can also poll the employees to see what they want to learn more about.