Dr Dale Rae, senior researcher, Division of Exercise Science and Sports Medicine, Department of Human Biology, and Rageema Joseph, PhD candidate, Department of Molecular and Cell Biology, UCT


A self-sustaining clockwork generates circadian rhythms inside the cells of most organisms. It is becoming increasingly apparent as we become more independent of the planetary day-night cycle that this internal clock has health implications. When travelling across time zones, circadian rhythms become out of phase with the day-night cycle, causing jet lag. Many live in a permanent state of desynchronisation, or ‘social jet-lag’. This can increase the risk for obesity, cardiovascular disease, type 2 diabetes and cancer. These lectures explore the mechanism governing the clockwork inside the cell, the importance of plants telling time, how our biological clocks are set by the environment and how they become desynchronised, what the best times for physical activity and sleep are, what happens to sleep and health when circadian rhythms and sleep are disrupted, and finally what can be done to optimise sleep.


1. What is a circadian clock? Circadian timing in plants: flowers and defence   Ms Rageema Joseph

2. Circadian rhythms in humans: resonance and disruption   Dr Dale Rae

3. Circadian aspects of physical activity and sleep   Dr Dale Rae

4. Circadian rhythms and sleep: perspectives on health and disease   Dr Dale Rae

5. Optimising sleep   Dr Dale Rae


Recommended reading

Koukkari, W.L. & Sothern, R.B. 2006. Introducing Biological Rhythms. New York: Springer Science + Business Media.

Dement, W.C. & Vaughan, C. 1999. The Promise of Sleep. New York: Dell Publishing.



Date: 21 – 25 January 
Time: 9.15 am
COURSE FEES Full: 550,00  Staff and Students R275,00
Venue: LT3 Kramer Law Building UCT