Four out of five workers in Korea feel exhausted when they return to work after summer vacation, a poll showed on Thursday.According to Job Korea, a local online job search engine, about 77.8 percent of 457 respondents said that they are suffering from lingering fatigue from summer holidays.Of those who are still stressed, 72.9 percent said they have “lost morale to work and feel listless,” while others also said they had problems like sleeping disorder, headache, or skin diseases.On average, it took about 2.5 days to completely recover from such side effects.In order to recover from such depression, respondents tried to “live a more regular life,” “sleep more,” or “avoid drinking and go home early.”By Kang Yoon-seungIntern reporter