Participant characteristics
| Characteristic | Mean | Range |
|---|---|---|
| Age | 22 yr | 18–28 yr |
| Weight | 100 kg | 59–115 kg |
| Alcohol consumption (n = 14) | 6 Drinks/week | 2–16 Drinks/week |
| Nicotine consumption (n = 10) | 83 Cigarettes/week | 35–140 Cigarettes/week |
| Caffeine consumption (n = 12)1-a | 648 mg/week | 60–1680 mg/week |
↵1-a Twelve of 14 volunteers reported current use of caffeine. The two remaining volunteers reported that although they did not currently consume caffeine, they did not actively avoid it.