Just don’t get sick…
So, my serious answer is that I plan 48 weeks of training per year, and 4 “recovery” weeks. The recovery week is every 13th week. No matter what, my group classes will not run on those 4 weeks per year. If I intend on taking a vacation, I try to schedule it during these 4 weeks. I pretty much intend on taking 2-3 of those weeks per year completely off. So, my clients will know ahead of time that we won’t be training during those weeks. They will receive some workout ideas for this time off, but most of it will be more on the recovery side of things because they need a break too.
As far as getting sick, I don’t think it works well to have a replacement. I haven’t tried it before, but you would have to make sure that the person is trained well enough to not hurt your clients. If they do have this much training, they likely have a client base of their own. I just don’t know many qualified trainers who are sitting at home willing to work when they get that call.
Those days where you can’t work are why I decided to save 8% of what I make training as sort of a PTO fund. Basically 48 weeks * 5 days per week is 240 and I assume that I will take up to 20 days off per year (max), so that is where I get the 8%. You could just pay yourself the higher rate and take it out of your personal emergency fund, but I like the separation. If I have to take a day off, I just take my average pay out of the fund and I’m good to go.