All you have to do, is do the exercise of the day and post that you've done it!
There's on via email and there's a different one in the "today on Spark" bar on the right. You can choose.
Also, if you don't have the equipment for it or physical limitations prevent it, do something that approximates it within your equipment and abilities. Eg today's is Assisted Triceps Dip Machine. I don't have one, so I'll do some standard tricep dips off my coffee table instead.
Deb, in New Zealand