Our natural body clocks mean some people are naturally ‘morning types’ whereas others prefer evenings. For many people, the way their natural internal body clock is inclined can make the demands and schedules of work and lifestyles especially challenging. The standard 9-5 Monday to Friday work week is ideal for morning types because their body clock prepares them to fall asleep early at night and to be active early in the morning.
Evening types can find it difficult to cope with a standard work week and experience social jetlag. Social jetlag occurs when the timing of our sleep is not matched with that of our body clock. The symptoms of social jetlag are the same as the jetlag we experience when travelling across time zones and include fatigue and irritability.
Individual types can be identified by taking the test on the following link
While a majority of people, at 35%, are classed as ‘moderate morning types,’ meaning they feel best waking up between 5am to 6:30am and going to bed between 9:30pm to 10:45pm, 30% are ‘moderating evening types’ (waking 8:30am-10am, bedtime 12:45am-2am) and 27% are ‘definite morning types’ (waking 4am-5am, bedtime 9pm-9.30pm). A smaller part of the population are ‘definite evening types,’ with 8% preferring to wake 10am to 11:30am and go to sleep 2am-3am*.
These patterns change in a predictable way across people’s lifespans. Perhaps unsurprisingly, during adolescence (10-19 years) most people drift towards the evening type, before shifting to become more morning types as they grow older. In addition, men are more likely to be at the extreme end of the morning and evening scale compared to women.
Dr Alexandra Holmes, Research Director at Baines Simmons specialising in fatigue risk management in aviation and other safety-critical industries, offers the following advice to help people adapt their body clocks:
“Harnessing opportunities to work flexible work hours can enable evening types to adjust their work timings so that they can be more alert and efficient at work. Research shows that matching shift schedules to types increases sleep duration by an average of one hour.
“If you are an evening type struggling with social jetlag and want to be able to go to sleep earlier, research has shown that a camping trip in the countryside can be beneficial. When we go camping and are exposed to bright light all day, and there is a lack of electrical light at night, our circadian rhythms are re-set so that we go to bed earlier and sleep longer**.
“Try to make complementary choices about your work hours and how to spend your time off. For example, if you are a morning type, do not volunteer to work the night shift. On the other hand, if you are an evening type and want to volunteer for overtime, shifts that finish late would be a good choice.
“Of course, many of us inevitably do have to work hours that do not match our type. If you are a morning type who has to work late shifts, heavy curtains in your bedroom can help you to avoid exposure to sunlight in the early morning and allow you to sleep later.
“If you are an evening type working shifts that start early, try to avoid caffeine and bright light in the evening. Using electronic devices such as smartphones should also be avoided at least two hours before you go to bed because they emit bright light that increases alertness”.
* Source: Knutson, K. L., & von Schantz, M. (2018). Associations between chronotype, morbidity and mortality in the UK biobank cohort. Chronobiology International, 35(8), 1045-1053
** Source: Stothard, E.R., McHill, A.W, Depner, C.M., Birks, B.R., Moehlman, T.M., Ritchie, H.K., Guzzetti, J.R.Chonoy, E.D., LeBourgeois, M.K., Axelsson, J., & Wright, K.P. (2017).Circadian entrainment to the natural light-dark cycle across seasons and the weekend. Current Biology, 27(4), 508-513.