Discussion
This is a survey on the recovery after COVID-19 infection, including the
symptoms after infection, the impact on psychology and sleep. A total of
1013 Chinese residents were surveyed. The results showed that 91.21%
had fever after infection, most respondents had fatigue, muscle and
joint pain, sore throat, nasal congestion and runny nose and cough and
sputum, Kessel et al. also showed that[13] the
symptoms of patients infected with COVID-19 can be divided into
physical, mental and social symptoms. Besides, the lingering symptoms of
COVID-19 infection can have a significant impact on work and daily
functioning. Previous studies have shown that it can take 60 days or
longer for some infected people to recover from
symptoms.[14, 15] The most common symptoms are
fatigue, muscle soreness, etc., and older people, women and people with
other diseases have a higher risk of fatigue,[16]in addition, this study also found that cough, expectoration and changes
in taste and smell are also the same.
In this survey, the time to turn negative after infection ranged from 2
days to 39 days, 71.27% of the infected people turned negative for
about a week, and a small part of them turned negative for more than 20
days. Multiple studies showed that the time from the diagnosis of
infection to the negative test was one to two weeks for more than
two-thirds of the interviewees. Generally, the virus needed 1-2 weeks to
disappear in the body. More severe viruses can take up to six
weeks.[17] Regular physical exercise can help
prevent infection and reduce infection
symptoms,[18] which is consistent with the results
of this study.
Cardiopulmonary endurance was significantly lower after COVID-19
infection than before infection, a finding similarly reported by Singh
et al. Peak oxygen uptake (VO2peak) was significantly
lower in patients who recovered from COVID-19 compared to before
infection[19] (70±11% vs 131±45% P <
0.01), and the better the cardiopulmonary endurance level was after
infection, there was a significant positive correlation between
cardiopulmonary endurance level and the time of negative conversion with
the shorter time of negative conversion. Clinton A. et al. found
patients infected COVID-19 with poor cardiorespiratory endurance had a
higher risk of hospitalization.[20] Therefore, we
need to pay more attention to our cardiopulmonary function, people who
have not been infected with COVID-19, we should call on them to
participate in regular exercise. For people who are experiencing
COVID-19 infection or have been infected, it is suggested to reduce
unhealthy lifestyle and gradually recover or start their own exercise.
We should all improve our awareness of cardiorespiratory endurance and
the health benefits it can bring.
Surveys on anxiety show that women are more anxious than men, which may
be related to women’s higher psychological
susceptibility.[21] Previous studies on SARS
survivors have also found women have higher levels of stress, anxiety
and depression.[22] There is a significant
difference between the number of symptoms of infection and GAD-7 score.
The more symptoms there are during infection, the higher the GAD-7
score, that is, the more anxious the infected person will be. A
meta-analysis showed that among the patients surveyed, at least one
symptom persists, which is a common situation.[23]Therefore, attention needs to be paid to the mental health problems
caused by COVID-19 infection, especially for those at risk. Sleep
quality was significantly decreased after infection, which, like
anxiety, was more significant in women. In a previous survey, sleep
quality is also correlated with mental health,[24]which is consistent with the results obtained in this paper.
The survey on regular exercise and sedentary situation showed that
31.49% had regular exercise habits and 39.68% were sedentary people.
After COVID-19 infection, 75.32% stopped their original exercise
habits, which may be related to the widespread media reports that it is
not appropriate to exercise immediately after COVID-19 infection. It can
be seen that people’s lives will be more or less changed after COVID-19
infection, and exercise is one of the factors affected. Our research
conclusion suggests that the time to turn negative and to decrease fever
in sedentary people is significantly longer than that in non-sedentary
people, and the time to decrease fever in people who exercise
irregularly is significantly longer than that in people who exercise
regularly. A study by Chen et al on physical activity and risk of
hospitalization for COVID-19[25] shows that
sedentary behaviors such as watching TV, this suggests that we should
increase physical activity in daily life, reduce sedentary time, and
exercise appropriately to improve physical fitness. Other recent studies
have shown that low energy expenditure as shown by a higher BMI is
highly associated with the risk of hospitalization and severe
complications of COVID-19,[26] but our study did
not support this view, which may be related to the fact that the
population we investigated was patients with mild COVID-19 infection.
The benefits of increased physical activity may not end there. Meyer et
al. ’s investigation[27] pointed out that
maintaining and strengthening physical activity participation and
reducing screen time during the COVID-19 pandemic may reduce mental
health hazards, and increasing physical activity is an effective
strategy to address the physical and mental health risks of the COVID-19
pandemic.[28] This has also been demonstrated at
the molecular mechanism level.[29]
In order to properly evaluate the results of this paper, some
limitations should be considered. First of all, this study was an
anonymous online questionnaire survey, and the respondents were mostly
aged 18-25 and highly educated. Second, this survey is a cross-sectional
study, lacking follow-up data and using a scale instead of face-to-face
interviews, so it can only indicate that the subjects do have anxiety or
sleep problems to a certain extent, but medical diagnosis cannot be
made. Moreover, the long-term impact of COVID-19 on mental health may
come from infection of people around them or socio-economic problems.
Follow-up studies are needed to investigate psychological changes.
Third, because the online questionnaire survey relies on smart phones,
there are relatively few data for teenagers and the elderly. Fourth, the
sample size is not large enough, and there may be some correlations
between variables that cannot be observed. Fifth, the proportion of
women in this survey is also higher than that of men, which makes up for
the lack of female data in some previous articles. However, there may be
some bias in the study due to the large sample of women. In addition,
the subjects of this study were mainly asymptomatic or mildly infected
Omicron variants of novel coronavirus, which did not represent the
status of patients with severe/critical illness.