Office manager: Every vacation an office worker takes significantly reduces the psychological exhaustion experienced on the job.
Conclusion
To reduce psychological exhaustion as much as possible over the year, workers should divide their vacation time in several short vacations, rather than one or two long ones.
Evidence
Each vacation a worker takes significantly reduces the psychological exhaustion experienced on the job.
Evaluate
The author is thinking,
When author's have Plans / make Recommendations, we're implicitly judging a comparison between this world and the alternative world in which we follow their Plan/Rec. What else might be different in that world?
If I were trying to argue against this argument, I would say that people might rather have a couple longer vacations, because it allows them to go to Europe or Africa or Asia or what have-you.
3-4 day vacations get kind of limiting, because you're usually staying within driving distance.
Also, are we sure that people come back from these "long weekends" super refreshed, or does it need to be 8 days down in Cabo ... deep time, doin' nothin', that allows workers to be psychologically replenished?
Goal
Look for an answer making objections that there would actually be more psychological exhaustion in this world of shorter vacations, either because we wouldn't like our vacation options as much or because we wouldn't get the stress relief of deep time from longer vacations.