Jun 23, 2021


Physicians and psychologists around the world have surmised that the COVID-19 pandemic had a very negative effect on many young people’s health and mood, but they had no way to prove it. 


Now, in a first-of-its-kind study, researchers from Tel Aviv University (TAU) and the Academic College of Tel Aviv-Yaffo have scientific proof, based on data from “smartwatches” and a dedicated application to monitor 169 subjects before and during Israel’s second COVID-19 lockdown (from May to October 2020). 


During the lockdown period, restaurants, schools, hotels, fitness clubs, swimming pools, malls and all other facilities (except for food stores and pharmacies) were closed, and people’s movement was restricted to 500 m from their homes (except for commuting to work and to other essential activities).


The watches and app provided the researchers with accurate daily data for measuring the quality of life characteristics such as mood, stress, duration and quality of sleep, heart rate at rest, meeting others, and physical exercise. The team aimed at finding out whether age, gender and chronotype moderate the effects of such changes on well-being using both wearable monitoring devices (Fitbit) and daily self-reported digital questionnaires.


The study was conducted by a group of experts from the Fleischman Faculty of Engineering at Tel Aviv University led by Dr. Erez Shmueli, Dr. Dan Yamin, Shay Oved and Merav Mofaz, in collaboration with TAU’s Prof. Noga Kronfeld Schor of the School of Zoology at the university’s Faculty of Life Sciences and the Sagol School of Neuroscience, and Dr. Anat Lan and Prof. Haim Einat of the Academic College of Tel Aviv-Yaffo. 

The study was recently published at the leading Journal of the Royal Society Interface under the title “Differential effects of COVID-19 lockdowns on well-being: interaction between age, gender and chronotype.” The unprecedented restrictions imposed due to the COVID-19 pandemic altered our daily habits and severely affected our well-being and physiology. The effect of these changes is yet to be fully understood,” the authors stated. 


The data they collected showed that, in the general population during the lockdown, the subjects slept more (6:08 vs. 6:01 hours) met fewer people face to face (11.5 vs. 7.8 daily encounters), exercised less (30 vs. 27 minutes), walked less (daily step count of 8,453 vs. 7,710) felt less happy (0.87 vs. 0.76 on a scale of -2 to 2) and exhibited a lower heart rate at rest (62.6 vs. 62.1 beats per minute).


Among the young participants, a more substantial drop was registered in the daily step count – from 9,500 steps before to 8,200 steps during the lockdown. In comparison, the average daily step count in people aged 60 years and over decreased from 7,500 to 7,200.


The lockdown was also very damaging to the moods of younger subjects. On a scale of -2 to 2, their average score declined from 0.89 before to 0.72 during the lockdown, while older subjects reported only a small decrease – from 0.85 to 0.8.


Interestingly, when focusing on the younger age group, the increase in how much time they slept was expressed mainly in late chronotypes (the tendency of the individual to sleep at a particular time during a 24-hour period) — 7:05 hours before vs. 7:24 during the lockdown.


Late chronotypes, especially in the age of our younger group which usually work or study and have younger children normally suffer sleep loss.  With no need to wake up the children or carry out everyday obligations, the more relaxed social schedule induced by the lockdown could allow them to wake up later without using an alarm clock and increase their time sleeping. In contrast, when zooming in on the older age group, the increase in sleep-duration was mainly expressed in early chronotypes (6:48 hours before vs. 6:58 during the lockdown). It is possible that this population could not perform some early social activity like group sports, but other explanations may also be possible.


Analysis by gender revealed that while men’s stress level decreased from -0.79 before to -0.88 during the lockdown, women’s stress rose from -0.62 to -0.52. The researchers suggest several possible explanations for these findings. 


First, according to Israel’s Finance Ministry, more women lost their jobs (fired or sent to unpaid vacation) than men. Second, schools and day-care centers were closed during lockdowns. and parents to young children had to stay with them at home. Several studies reported that during lockdowns, men were more concerned about paid work while women were more worried about childcare. Third, according to Israel Police data, domestic violence against women increased during lockdowns.


In addition, the lockdown was more ‘effective’ in keeping women from meeting others face to face. While for men, the number of such encounters decreased from 11 to nine, women reported a sharper decline from 12 to seven daily encounters on average. Face to face encounters, even a random meeting with a neighbor or a public transportation driver, are known to improve people’s mood and reduce depression and anxiety. 


“During lockdowns, women were more secluded and stressed than men, and generally their welfare and mental health were significantly more affected than those of the men,” Shmueli added. “We were lucky. Roughly two years before the outbreak of the pandemic, we planned a large-scale experiment with the goal of providing earlier and improved diagnosis of infectious diseases, by integrating multiple sources of data such as self-reported questionnaires and smart watches. Clearly, we didn’t have COVID-19 in our mind back then, but the running experiment allowed us to monitor subjects for a relatively long period before and during the second lockdown in Israel.”


The findings, he continued, “are important by themselves and suggest that certain subpopulations should receive more attention than others during lockdowns. However, in addition to the direct negative effects of lockdowns on wellbeing, lockdowns may also indirectly affect our immune system – it is well known that mood, stress, physical activity and sleep duration and quality have a major effect on our immune system. Paying more attention to the affected subpopulations may therefore help in coping better with the virus and even improve the effectiveness of vaccines.”