title: Caffeine maintains vigilance and improves run times during night operations for Special Forces.
abstract: OBJECTIVE
  This study examined the effects of caffeine (CAF) on vigilance, marksmanship, and run performance during 27 h of sustained wakefulness in Special Forces personnel.
  
  
  METHODS
  There were 31 soldiers (29.8 +/- 5.4 yr, 86.4 +/- 8.6 kg) who were divided into placebo (PLAC, n = 15) and CAF (n = 16) groups. A 6.3-km control run was completed on the morning of Day 1. In the evening of Day 2, soldiers performed a control observation and reconnaissance vigilance task (ORVT) in the field. This 90-min task was repeated twice more between 02:00 and 06:00 on Day 3 during an overnight period of sleep deprivation. Marksmanship was assessed before and after the ORVT. PLAC or 200 mg of CAF gum was administered at 01:45, 03:45, and approximately 06:30 on Day 3. A final 6.3-km run commenced within 30 min of receiving the final dose.
  
  
  RESULTS
  ORVT was maintained in CAF at control levels of 77 +/- 13% during the overnight testing. However, values decreased significantly for PLAC from 77 +/- 15% to 54 +/- 29% and 51 +/- 31% during the first and second overnight testing periods, respectively. CAF had no effect on marksmanship but improved 6.3-km run times by 1.2 +/- 1.8 min. Run times slowed for PLAC by 0.9 +/- 0.8 min from approximately 35 min during the control run; the changes in performance were significant between groups.
  
  
  CONCLUSIONS
  It was concluded that CAF maintained vigilance and improved running performance during an overnight field operation for Special Forces personnel.
authors: DRDC Toronto, Toronto, ON, Canada. tom.mclellan@drdc-rddc.gc.ca
authors: Tom M
authors: TM
authors: McLellan
authors: Gary H
authors: GH
authors: Kamimori
authors: David M
authors: DM
authors: Voss
authors: Douglas G
authors: DG
authors: Bell
authors: Karl G
authors: KG
authors: Cole
authors: Dagny
authors: D
authors: Johnson
mesh_terms: D000328:Adult; D002110:Caffeine / Q000008:administration & dosage* / Q000494:pharmacology; D002940:Circadian Rhythm / Q000187:drug effects*; D005389:Firearms; D006801:Humans; D008297:Male; D008887:Military Medicine; D008889:Military Personnel; D009520:New Zealand; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D012420:Running / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
chemical_list: D002110:Caffeine