What does this expression mean: "sound health"?

[Mala]

Sir,

Could you have a look at the following statement. Do you think its grammatically correct?

"Imagine if you are not healthy just for a single day. Your whole schedule for the day gets disrupted and the schedule for subsequent or linked activities also get affected."

Thanks.
Regards

[Mister Micawber]

.
It is grammatically correct, but could do with some styling:

Imagine that you are unhealthy for just a single day: your whole schedule is disrupted and all subsequent activities are affected.

Also, remember that its means belonging to it, and it's means it is/has.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber