| All zeitgebers mirror the cycle length of the earth's rotation and they therefore shaped circadian systems as they evolved. |
| The major zeitgebers pertinent to athletic performance include diet, daylight and temperature, exercise, social interactions, and drugs. |
| You are in conflict with all of the zeitgebers around you, and your need to work preserves this conflict. |
| Several candidates have been suggested as the zeitgebers for peripheral clocks, including glucocorticoids, retinoic acid and melatonin. |
| Much remains to be learned about zeitgebers for these tissues. |
| Future studies will be required to answer these important questions, as well to identify the major zeitgebers affecting the circadian clock of the heart. |
