Studies related to and

Subjective, Behavioral, And Physiological Effects Of Acute Caffeine In Light, Nondependent Caffeine Users

Effect Decrease
Trial Design Double blind
Trial Length 24 hours
Number of Subjects 102
Gender Both Genders
Age Range 18-29, 30-44, 45-64
Body Types Overweight, Average
Notes for this study:
102 light, nondependent caffeine users were subject to varying doses of caffeine and tested for its psychostimulatory responses.

Sedation was significantly lowered and stimulation was higher, although still lesser to 20mg d-amphetamine (used as comparison) even when at 450mg caffeine. No significant interactions on euphoria or desire of 'more drug' were noted with caffeine, but were with d-amphetamine.

Performance on working memory was decreased at the 450mg dosage but processing speed at all doses was increased, most significantly at the 450mg dosage.

Effect Of Caffeine On Reactive Agility Time When Fresh And Fatigued

Effect Decrease
Trial Design Double blind
Trial Length n/a
Number of Subjects 10
Gender n/a
Notes for this study:
Caffeine ingestion, at 6mg/kg bodyweight, was able to slightly increase Reaction Time, Decision Time, and Movement Time when ingested in either fatigued or fully rested athletes.

Effects Of Caffeine And Glucose, Alone And Combined, On Cognitive Performance

Effect Increase
Trial Design Double blind
Trial Length n/a
Number of Subjects 72
Gender n/a
Notes for this study:
75mg of caffeine was ineffective in isolation in improving the parameters of learning and verbal consolidation (memory), but became effective when paired with 75mg glucose.

Caffeine in isolation was able to improve reaction time tests at 75mg.

Effects Of Caffeine On Repeated Sprint Ability, Reactive Agility Time, Sleep And Next Day Performance

Effect None
Trial Design Double blind
Trial Length n/a
Number of Subjects 10
Gender n/a
Notes for this study:
6mg/kg caffeine ingested 1 hour before exercise was able to increase intermittent sprint performance (best time and overall volume) but had no significant effect on reaction time.

Effects Of Diurnal Variation And Caffeine Consumption On Test Of Variables Of Attention (TOVA) Performance In Healthy Young Adults

Effect Increase
Trial Design Double blind
Trial Length n/a
Number of Subjects 64
Gender n/a
Notes for this study:
After 200mg caffeine, performance on the Test of Variables of Attention (TOVA) used for ADHD diagnosis showed increases in mental reaction and processing speeds in persons who routinely consumed little caffeine.

Individuals who routinely consumed more than 120mg caffeine were not affected in the same manner as naive users.