Jet|NNP Lag|NN :|: Pathophysiology|NNP and|CC Cures|NNP The|DT longest|JJS Monday|NNP of|IN my|PRP$ life|NN I|PRP recently|RB returned|VBD to|TO the|DT US|NNP from|IN Australia|NNP .|. 
The|DT 14-hour|JJ flight|NN took|VBD me|PRP from|IN Monday|NNP morning|NN in|IN Sydney|NNP to|TO Monday|NNP morning|NN ,|, again|RB ,|, in|IN L.A.|NNP Crossing|NNP the|DT date|NN line|NN messed|JJ up|RP my|PRP$ sense|NN of|IN time|NN enough|RB without|IN the|DT added|JJ bonus|NN of|IN thinking|VBG I|PRP should|MD be|VB heading|VBG to|TO bed|NN just|RB as|IN the|DT sun|NN began|VBD to|TO climb|VB into|IN the|DT California|NNP sky|NN .|. 

You|PRP may|MD be|VB familiar|JJ with|IN the|DT concept|NN :|: Jet|NNP lag|NN .|. 
The|DT catch-all|JJ name|NN for|IN circadian|NN misalignment|NN ,|, the|DT disruption|NN of|IN sleep|NN cycles|NNS and|CC circadian|NN rhythms|NNS .|. 
If|IN you|PRP 've|VBP had|VBN the|DT pleasure|NN of|IN crossing|VBG time|NN zones|NNS in|IN a|DT jet|NN plane|NN ,|, whether|IN it|PRP was|VBD a|DT mere|JJ three-hour|JJ hop|NN from|IN one|CD coast|NN of|IN the|DT US|NNP to|TO the|DT other|JJ or|CC a|DT trip|NN to|TO another|DT continent|NN ,|, chances|NNS are|VBP ,|, you|PRP 've|VBP experienced|VBN some|DT amount|NN of|IN jet|NN lag|NN .|. 

The|DT pathophysiology|NN of|IN jet|NN lag|NN Normally|RB ,|, two|CD systems--the|JJ homeostatic|JJ system|NN and|CC the|DT circadian|NN system--work|JJ together|RB to|TO produce|VB a|DT 24-hour|JJ sleep|NN cycle|NN .|. 
During|IN the|DT day|NN ,|, the|DT homeostatic|JJ system|NN slowly|RB accumulates|NNS a|NNP '|POS sleep|NN drive|NN ,|, '|'' a|DT desire|NN to|TO sleep|VB that|IN increases|NNS as|IN a|DT function|NN of|IN time|NN spent|VBD awake|JJ .|. 
The|DT circadian|NN system|NN generates|VBZ an|DT alerting|VBG signal|NN in|IN opposition|NN to|TO this|DT sleep|NN drive|NN ,|, which|WDT ,|, during|IN the|DT day|NN ,|, keeps|VBZ a|DT person|NN from|IN feeling|NN increasingly|RB sleepy|JJ .|. 
An|DT hour|NN or|CC two|CD before|IN bedtime|NN ,|, this|DT signal|NN subsides|NNS ,|, and|CC s|VBZ /|NN he|PRP realizes|VBZ it|PRP 's|VBZ time|NN to|TO hit|VB the|DT pillow|NN .|. 
The|DT sleep|NN drive|NN dissipates|VBZ as|IN a|DT person|NN sleeps|VBZ and|CC by|IN morning|NN (|( assuming|VBG a|DT full|JJ night|NN 's|POS rest|NN and|CC possibly|RB some|DT coffee|NN )|) ,|, s|VBZ /|NN he|PRP will|MD be|VB feeling|VBG alert|VB and|CC ready|JJ to|TO go|VB again|RB .|. 

Robert|NNP Sack|NNP wrote|VBD a|DT delightful|JJ paper|NN [|NN PDF|NNP ]|NN on|IN jet|NN lag|NN ,|, by|IN the|DT way|NN ,|, which|WDT is|VBZ where|WRB I|PRP 'm|VBP getting|VBG much|JJ of|IN my|PRP$ information|NN .|. 

So|IN we|PRP 've|VBP got|VBN a|DT nice|JJ cycle|NN of|IN sleep|NN .|. 
Jet|NNP lag|NN is|VBZ what|WP happens|VBZ when|WRB the|DT homeostatic|JJ and|CC circadian|NN processes|NNS are|VBP misaligned|JJ .|. 
For|IN example|NN ,|, the|DT circadian|NN system|NN may|MD signal|VB a|DT person|NN to|TO be|VB alert|VB when|WRB it|PRP 's|VBZ not|RB actually|RB morning|NN ,|, or|CC may|MD be|VB reduced|VBN during|IN daytime|JJ hours|NNS ,|, causing|VBG daytime|JJ sleepiness|NNS because|IN the|DT homeostatic|JJ sleep|NN drive|NN is|VBZ no|DT longer|RB cancelled|JJ out|RP .|. 

But|CC I|PRP do|VBP n't|RB want|VB to|TO be|VB sleepy|JJ !|. How|WRB do|VBP you|PRP beat|VBP jet|NN lag|NN ?|. 
Robert|NNP Sack|NNP lists|NNS three|CD primary|JJ approaches|NNS :|: 
Reset|NNP the|DT body|NN clock|NN 
Prescribed|NNP sleep|VB scheduling|NN 
Medication|NNP to|TO counteract|VB daytime|JJ sleepiness|NNS or|CC insomnia|NN 

Let|VB 's|PRP start|VB with|IN the|DT first|JJ one|CD ,|, as|IN it|PRP turns|VBZ out|IN to|TO be|VB the|DT most|RBS complicated|VBN .|. 

Resetting|NNP the|DT body|NN clock|NN The|DT two|CD most|RBS effective|JJ ways|NNS to|TO reset|VB the|DT body|NN clock|NN are|VBP 1|CD )|) through|IN bright|JJ light|JJ exposure|NN ,|, and|CC 2|CD )|) timed|VBN melatonin|NN administration|NN .|. 

Light|NNP is|VBZ one|CD of|IN the|DT most|RBS important|JJ cues|NNS about|IN time|NN of|IN day|NN and|CC has|VBZ the|DT greatest|JJS effect|NN on|IN circadian|NN timing|NN (|( much|RB smaller|JJR effects|NNS are|VBP seen|VBN from|IN regular|JJ activities|NNS and|CC meals|NNS ,|, for|IN example|NN )|) .|. 
Studies|NNS have|VBP shown|VBN that|IN without|IN light|JJ cues|NNS ,|, totally|RB blind|JJ people|NNS tend|VBP to|TO have|VB free-running|JJ circadian|NN rhythms|NNS with|IN an|DT average|JJ period|NN of|IN 24.5|CD hours|NNS ,|, instead|RB of|IN the|DT usual|JJ 24|CD .|. 
If|IN a|DT person|NN is|VBZ exposed|VBN to|TO bright|JJ light|JJ early|RB in|IN the|DT day|NN ,|, the|DT person|NN 's|POS internal|JJ clock|NN is|VBZ reset|NN to|TO an|DT earlier|JJR time|NN ;|: if|IN exposure|NN is|VBZ instead|RB in|IN the|DT evening|NN ,|, the|DT internal|JJ clock|NN is|VBZ reset|NN to|TO a|DT later|JJ time|NN .|. 
Brighter|NNP light|NN has|VBZ more|JJR of|IN an|DT effect|NN (|( such|JJ as|IN the|DT sun|NN ,|, at|IN 3000|CD to|TO 10,000|CD lux|NN )|) ,|, though|IN lower|JJR intensities|NNS (|( e.g.|NN ,|, 100|CD -|: 550|CD lux|NN )|) can|MD produce|VB changes|NNS .|. 

Artificial|NNP light|JJ sources|NNS can|MD be|VB used|VBN to|TO supplement|VB daylight|NN ,|, to|TO help|VB reset|VB a|DT person|NN 's|POS internal|JJ clock|NN to|TO the|DT correct|JJ new|JJ time|NN zone|NN when|WRB traveling|VBG .|. 
Alternatively|RB ,|, a|DT person|NN could|MD wear|VB very|RB dark|JJ glasses|NNS ,|, as|IN light|JJ avoidance|NN could|MD help|VB minimize|VB the|DT problems|NNS of|IN light|JJ exposure|NN at|IN the|DT wrong|JJ time|NN of|IN day|NN or|CC night|NN .|. 

Resetting|NNP the|DT body|NN clock|NN ,|, Part|NN 2|CD :|: Melatonin|NNP Melatonin|NNP is|VBZ a|DT hormone|NN that|WDT has|VBZ been|VBN linked|VBN to|TO the|DT regulation|NN of|IN circadian|NN rhythms|NNS and|CC sleep|VB cycles|NNS [|NN PDF|NNP ]|NN .|. 
Melatonin|NNP is|VBZ secreted|JJ by|IN the|DT pineal|NN gland|NN at|IN night|NN ;|: secretion|NN is|VBZ suppressed|VBN by|IN light|JJ exposure|NN ,|, and|CC as|IN such|JJ ,|, the|DT hormone|NN can|MD be|VB thought|VBN of|IN as|IN a|DT "|'' darkness|NNS signal|VBP .|. "|'' 
If|IN doses|NNS of|IN melatonin|NN are|VBP administered|VBN in|IN the|DT morning|NN ,|, circadian|NN rhythms|NNS will|MD be|VB shifted|VBN later|RB ;|: evening|NN doses|NNS shift|VBP rhythms|NNS earlier|RBR .|. 
Timing|NN of|IN the|DT doses|NNS is|VBZ more|RBR important|JJ than|IN amount|NN per|IN dose|NN ,|, though|IN it|PRP remains|VBZ to|TO be|VB seen|VBN what|WP the|DT optimal|NN dose|NN and|CC optimal|NN time|NN of|IN administration|NN is--trials|JJ have|VBP been|VBN done|VBN with|IN doses|NNS from|IN 0.5|CD to|TO 10|CD mg|NN ,|, at|IN times|NNS ranging|VBG from|IN three|CD days|NNS before|IN departure|NN to|TO five|CD days|NNS after|IN arrival|NN in|IN the|DT new|JJ time|NN zone|NN .|. 

If|IN doses|NNS of|IN melatonin|NN are|VBP combined|VBN with|IN light|JJ exposure|NN ,|, the|DT results|NNS are|VBP what|WP you|PRP might|MD expect|VB :|: synergistic|JJ if|IN both|DT are|VBP administered|VBN to|TO produce|VB a|DT time|NN shift|NN in|IN the|DT same|JJ direction|NN (|( both|DT earlier|JJR or|CC both|DT later|RB )|) ;|: antagonistic|JJ otherwise|RB .|. 

Sleep|VBP ,|, wake|NN ,|, sleep|VB ,|, wake|NN The|DT second|JJ way|NN to|TO beat|VB jet|NN lag|NN :|: Sleep|VBP at|IN weird|JJ times|NNS .|. 
Slowly|NNP adjust|VB your|PRP$ sleep|NN schedule|NN to|TO match|VB that|IN of|IN your|PRP$ destination|NN ,|, or|CC keep|VB your|PRP$ home|NN sleep|NN schedule|NN for|IN a|DT while|NN after|IN you|PRP arrive|VBP .|. 
The|DT problem|NN with|IN this|DT is|VBZ that|IN your|PRP$ sleep-wake|JJ schedule|NN wo|MD n't|RB match|VB up|RP with|IN that|DT of|IN the|DT people|NNS around|IN you|PRP ,|, and|CC if|IN you|PRP need|VBP to|TO be|VB awake|JJ for|IN breakfast|NN at|IN 7|CD am|VBP or|CC for|IN a|DT meeting|NN in|IN the|DT afternoon|NN ,|, your|PRP$ sleep|NN schedule|NN may|MD interfere|VB .|. 
Use|NN this|DT method|NN at|IN your|PRP$ own|JJ risk|NN .|. 

Drugs|NNS for|IN everything|NN Lastly|NNP ,|, we|PRP have|VBP sleep|VB medicines|NNS .|. 
As|IN you|PRP might|MD guess|VB ,|, hypnotic|JJ medications|NNS combat|NN insomnia|NN and|CC stimulants|NNS fight|VBP off|RP daytime|JJ sleepiness|NNS pretty|RB well|RB ,|, because|IN by|IN definition|NN ,|, that|DT 's|VBZ what|WP they|PRP do|VBP .|. 
Both|DT benzodiazepine|NN and|CC non-benzodiazepine|JJ drugs|NNS have|VBP been|VBN shown|VBN to|TO be|VB effective|JJ in|IN the|DT first|JJ case|NN ;|: for|IN the|DT latter|NN ,|, the|DT most|RBS common|JJ solution|NN is|VBZ to|TO consume|VB more|JJR coffee|NN [|NN PDF|NNP ]|NN .|. 
This|DT works|NNS !|. 
In|IN the|DT study|NN linked|VBD ,|, subjects|NNS were|VBD treated|VBN with|IN slow-release|JJ caffeine|NN or|CC with|IN melatonin|NN prior|RB to|TO a|DT long|RB eastward|RB flight|NN ;|: the|DT caffeine|NN subjects|NNS were|VBD less|RBR sleepy|JJ than|IN either|DT melatonin|NN or|CC placebo|NN .|. 
Granted|NNP ,|, caffeine|NN subjects|NNS also|RB took|VBD longer|RBR to|TO fall|VB asleep|RB later|RB and|CC awoke|VBD more|RBR frequently|RB ,|, but|CC that|DT may|MD be|VB a|DT risk|NN you|PRP have|VBP to|TO take|VB .|. 

Lagging|NNP behind|IN Light|NNP ,|, melatonin|NN ,|, drugs|NNS ,|, strange|JJ sleep|NN schedules|NNS .|. 
Of|IN course|NN ,|, the|DT only|JJ solution|NN that|WDT will|MD always|RB work|VB is|VBZ time|NN .|. 
The|DT homeostatic|JJ and|CC circadian|NN processes|NNS need|VBP to|TO realign|VB ,|, and|CC while|IN the|DT aforementioned|JJ ways|NNS of|IN beating|NN jet|NN lag|NN can|MD fast|RB track|VB the|DT process|NN ,|, it|PRP still|RB takes|VBZ time|NN .|. 

UPDATE|NNP :|: ;|: I|PRP was|VBD alerted|VBD by|IN a|DT friend|NN of|IN the|DT existence|NN further|JJ research|NN of|IN which|WDT I|PRP was|VBD unaware|JJ :|: Another|DT way|NN to|TO reset|VB your|PRP$ sleep-wake|JJ cycle|NN is|VBZ to|TO stop|VB eating|VBG .|. 
If|IN you|PRP fast|RB for|IN about|IN 12|CD to|TO 16|CD hours|NNS ,|, your|PRP$ body|NN clock|NN will|MD reset|VB ,|, with|IN whatever|WDT time|NN you|PRP break|VBP your|PRP$ fast|RB as|IN morning|NN .|. 
The|DT Fuller|NNP ,|, Lu|NNP ,|, &|CC Saper|NNP paper|NN [|NN PDF|NNP ]|NN ,|, published|VBN in|IN Science|NNP ,|, discusses|NNS the|DT mechanism|NN ,|, though|IN a|DT more|RBR recent|JJ paper|NN argues|VBZ that|IN the|DT Fuller|NNP et|CC al.|NN results|NNS are|VBP inconclusive|JJ .|. 

