Around 30 years of longhaul flying has left me little better at dealing with shift/night/timezone effects. I realise that flying usually has timezone changes whereas ATC shift patterns do not, however I feel there are significant similarities so my comments should be pertinent. I think, essentially, I learned two fundamental points over the years:
1) You generally find the the best (or perhaps least worst) way to deal with each work/rest pattern by trial and error. Everyone is different and what suits one may not necessarily suit another. For example some can rest, or even sleep, in anticipation of a night duty but many (including me) cannot.
2) The effects do certainly become more pronounced with advancing years. I agree with
DC10RealMan and
CAP493 that around the age of 40 the body becomes less tolerant of disruptive sleep/work patterns and recovery times both during and after such work patterns start to get longer; thereafter, and certainly by age 50, the effects progressively increase such that shift work (particularly nights) can then have a significant life effect.
I also agree with
CAP493 when he says:
The best H24 ATC shift cycles move backwards from mornings through afternoons to nights - this has been determined as being the least onerous on and most easily accommodated by, the body's circadian rhythm.
In my experience the human body generally adapts more readily to a sleep pattern which involves lengthening the 24-hour day, rather than to one which shortens it.
There is some interesting aeromedical reading (if you can stay awake long enough!) in a couple of Aerospace Medical Association research articles, namely
Clockwise and Counterclockwise Rotating Shifts: Effects on Sleep Duration, Timing, and Quality and
Rapid Counterclockwise Shift Rotation in Air Traffic Control: Effects on Sleep and Night Work. Both are free to download, in either HTML or pdf.
JD
