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Pacing yourself with light – post-exam recovery, micro-breaks and the summer solstice

Post-exam recovery – sleeping in is not the best solution

Lots of young people around me have finished their exams and don’t see the sun before noon. It may feel like a daily battle to get them out of bed- but here’s why it’s worth the fight – and some tips that will help.

Irregular sleep patterns are bad for long-term health –

A one standard deviation increase in sleep regularity predicted a 20.4±2.0% reduced risk of all-cause mortality. O020 Sleep regularity is a stronger predictor of all-cause mortality than sleep duration or sleep efficiency in ~60 000 UK Biobank participants.

Sleep accounts for up to 25% of variance in academic performance too. Sleep quality, duration, and consistency are associated with better academic performance in college students

So what’s that got to do with light?

The lighting in the average home is bright enough to disrupt the body clocks of around half of us. And homes with energy-efficient lights had nearly double the melanopic illuminance of homes with incandescent lighting. Evening home lighting adversely impacts the circadian system and sleep

Bright light in the morning sets the body clock so we fall asleep earlier – and wake up earlier the next morning too. Effects of light on human circadian rhythms, sleep and mood 

Dark nights are just as important: A standard lightbulb (100 lux) during sleep compared to dim light (3 lux) for just one night is enough to increase heart rate variability (a measure of stress) and sensitivity to insulin the next morning. Light exposure during sleep impairs cardiometabolic function.

Five tips to help them to be their best – 

  1. Set a Consistent Schedule: 🕙 Establish a regular bedtime and wake-up time, even on weekends. Consistency helps regulate your body’s internal clock and promotes better sleep quality. Aim for 7-9 hours of shut-eye each night!
  2. Get up and into daylight before 10am every day- it doesn’t have to be energetic – a coffee by an open window will be a good place to start
  3. Power Down Your Devices: 📱💻🚫 Say goodbye to screens at least an hour before bed. The blue light emitted by devices can disrupt your natural sleep hormones. Swap screen time for relaxing activities like reading a book or listening to calming music.
  4. Create a Peaceful Sleep Environment: 🌙✨ Make your bedroom a sleep-friendly oasis. Dim the lights, keep the temperature cool, and eliminate distractions. Invest in comfy bedding and block out any annoying noises. Create a cozy haven that invites deep slumber!
  5. Ditch the Late-Night Caffeine: ☕️⏰ Avoid caffeine and energy drinks in the late afternoon and evening. They can interfere with falling asleep and disrupt your sleep cycles. Opt for herbal tea or decaf options instead. Your future self will thank you!


Circannual rhythms and the solstice.

Wednesday marks the summer solstice in the Northern Hemisphere – and the day when your cortisol levels are likely to be at their lowest. 

From tomorrow, they’ll start to rise again – rising by around 5% for every hour delay in sunrise.  The effects of season, daylight saving and time of sunrise on serum cortisol in a large population

Cortisol levels are one valuable indicator not only of the daily or circadian rhythm (cortisol is considered the ‘complementary hormone to melatonin: ideally, one rises as the other falls).  Where in the world? Latitude, longitude and season contribute to the complex co-ordinates determining cortisol levels.

But this powerful cyclical seasonal variation confirms the findings of a huge analysis of over 46 million person-years that, just like animals, we experience ‘coordinated seasonal set-points with a winter−spring peak in the growth, stress, metabolism, and reproduction axes.’  Hormone seasonality in medical records suggests circannual endocrine circuits.

Time to celebrate the sun – and top up your Vitamin D levels for the winter that’s just around the corner. Vitamin D and your health: Breaking old rules, raising new hopes


Too busy to take a break?

You may be gulping down lunch at your desk because you want to get everything done before the weekend.

But you’ll be more productive if you take micro-breaks. 

15 minutes outside – even in a Norwegian winter – protected busy people against burn-out. Restorative experiences across seasons? Effects of outdoor walking and relaxation exercise during lunch breaks in summer and winter.

A break for lunch improved their protein and micro-nutrient intake too, boosting the benefits of that detachment too.  Recovery from work: testing the effects of chronic internal and external workload on health and well-being

A quick walk around the block will do at least three things that will help you tackle that to do list and get out of work on time –

  1. Daylight – likely to be tens if not hundreds of times brighter outside- will help you sleep better tonight and boost your alertness – can be as good as a coffee  Bright light alone or combined with caffeine improves sleepiness in chronically sleep-restricted young drivers
  2. Back pain – 53% of variance in back pain is linked to poor lighting – getting up will give your body a break  Musculoskeletal, visual and psychosocial stress in VDU operators after moving to an ergonomically designed office landscape
  3. Computer vision syndrome – a change of scene will increase blink rate and give dry and itchy eyes a break  Real-Time Blink Detection as an Indicator of Computer Vision Syndrome in Real-Life Settings: An Exploratory Study

You’ll get a bit of perspective on that list so you can make the most of the weekend and celebrate National Take Back the Lunch Break Day too. 


And finally, your body clock as a swing

A brilliant talk by Olivia Walch with some novel ways of thinking about light interventions and shift work – what if sleep was like being on a swing – you’d want to make sure you gave the system a push at the end of the curve, not in the middle. Olivia shares surprising ways that maths can help with the forced arhythmia caused by shift work and how light can help – Part of the excellent series by Manuel Spitzchan.

Olivia Walch: Understanding sleep, circadian rhythms and math modeling through shiftwork

Ps/ not too late to join me at the Care Managers Show next Friday 

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