The science
Read the published research
These are selected works from the research behind this library. A study's setting and participants matter when considering what it can tell you about travel.
Body-clock timing
Baehr, Revelle and Eastman (2000). Individual differences in the phase and amplitude of the human circadian temperature rhythm: with an emphasis on morningness-eveningness.
Duffy and colleagues (2011). Sex difference in the near-24-hour intrinsic period of the human circadian timing system.
Light and circadian timing
Khalsa, Jewett, Cajochen and Czeisler (2003). A phase response curve to single bright light pulses in human subjects.
Brown and colleagues (2022). Recommendations for daytime, evening, and nighttime indoor light exposure.
Sleep and naps
Daan, Beersma and Borbely (1984). Timing of human sleep: recovery process gated by a circadian pacemaker.
Brooks and Lack (2006). A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative?
Caffeine and sleep
Gardiner and colleagues (2023). The effect of caffeine on subsequent sleep: a systematic review and meta-analysis.
Gardiner and colleagues (2025). Dose and timing effects of caffeine on subsequent sleep: a randomized clinical crossover trial.
Sleep in flight
Doherty and colleagues (2023). The impact of long haul travel on the sleep of elite athletes.
Roach and colleagues (2018). Flat-out napping: the quantity and quality of sleep obtained in a seat during the daytime increase as the angle of recline of the seat increases.
Travelling across time zones
Waterhouse, Reilly, Atkinson and Edwards (2007). Jet lag: trends and coping strategies.
Some of this research comes from laboratories, athletes or flight crews rather than passengers on holiday. The works collected here do not establish how you will feel after following a ChronoFlow plan.
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