How lockdown and social distancing changed our sleep-wake cycles

22 Jul 2020

As the restrictions on public life gradually ease across Europe, we are only just starting to uncover the full effects on our mental and physical health.

At LYS, we’ve taken the chance to review our data for the last few months from the Light Diet® programme. 

The data gives a fascinating insight into how – and why – the pandemic has changed our daily routines and affected our wellbeing.

If you’ve struggled with your sleep during lockdown, our findings could help you identify the problem.

Here’s a summary of our findings so far.

We’re sleeping more, but not necessarily feeling more rested


Average sleep time (in hours)

Sleep during lockdownDuring lockdown, the time we spent asleep or in bed increased dramatically. LYS data suggests that average sleep time increased by almost 35 minutes. 

At first glance, this seems like good news. Increased sleep time has a range of benefits: from better mood and concentration to a stronger immune system.

However, despite the fact that sleep quantity increased, our data does not show a statistically significant improvement in people’s energy levels.

Perceived energy levels (self-rated 1-10)

Energy levels during lockdownDuring lockdown, sleep quality marginally increased. But for perceived energy levels, the results are flat.

So why, if we’re sleeping more, are we not feeling more rested? Stress, anxiety or reduced physical activity could all be factors.

But LYS data also suggests that light could be having a significant effect on our energy levels.

We’ve been exposed to higher levels of harmful light in the evening

Harmful evening light exposure (in minutes)

Harmful light during lockdownStudies show that high-intensity light before bed increases the time it takes to fall asleep and disturbs sleep quality. It seems that with less time outdoors and no social plans, people spent significantly more time looking at screens in the evening.

We’ve had less natural light during the day

Natural light exposure (minutes)

As you might expect, people have spent more time indoors. Whilst this might seem straightforward, it’s easy to forget the knock-on effects. The data shows that the changes to our daily routines have made a big difference to our light exposure. 

Light has a profound influence on how well we sleep and how energised we feel. These results potentially explain why energy levels haven’t improved despite people spending more time in bed.

Our internal clocks have drifted to Night Owl

Chronotype comparison

Chronotype comparison

Overall, people’s sleep-wake cycles became more evenly distributed. There was also a trend away from early types towards late types. In other words, more people acted like ‘Night Owls’ during lockdown.

One explanation could be that remote-working means people settled into their natural rhythms. With no commute and more flexible schedules, people may have had more freedom to live according to their true internal clock.

However, morning light could also be a factor in the drift towards later chronotypes.

We’re getting less morning light

Early Morning Light (Light Diet® goal out of 100)

Morning light is crucial for maintaining regular sleep patterns. It’s the environmental cue that ‘sets’ our internal clock. Without good levels of light in the morning, people will tend to drift and wake up later in the day.

It’s possible that this trend contributed to the overall shift towards later chronotypes. Our lack of morning light potentially made it more difficult to wake up on time and stick to a regular routine. 

The LYS Light Diet®

If you’ve struggled with your sleep during lockdown, the problem could well be light.

Small changes to your daily routine – such as minimising screen time before bed and getting as much light in the morning as possible – are simple steps that could make a big difference to your sleep, mood and energy levels.

To help people stay happy and healthy, we’ve created an innovative wellbeing programme called the LYS Light Diet® . 

Using a discrete wearable sensor, the 2-week programme analyses the impact of light on your health and wellbeing. Designed to coach you to better habits, the Light Diet® gives insightful tips and advice on how to live healthier with light.

Find out more about the LYS Light Diet®