Table 1.

Variables obtained at test in individuals who ingested (1) a placebo; (2) three mg of caffeine per kg of body mass (received caffeine); and (3) a placebo, but they were told they were given three mg of caffeine per kg mass (informed caffeine).

Variable (Units)	Placebo	Received Caffeine	Informed Caffeine	p
Resting heart rate (beat/min)	53 ± 8	52 ± 8	53 ± 9	0.509
Systolic blood pressure (mmHg)	116 ± 12	119 ± 9	117 ± 9	0.639
Diastolic blood pressure (mmHg)	66 ± 10	68 ± 7	66 ± 6	0.191
Urine specific gravity	1.013 ± 0.006	1.014 ± 0.005	1.017 ± 0.003	0.271