Performance/Cognition/Weight

Caffeine

The world's most widely consumed psychoactive substance and one of the most rigorously proven ergogenic aids, enhancing endurance, strength, power, attention, and fat oxidation.

Caffeine

Caffeine

92
score
A
evidence
Caution
risk

Proven Benefits

01Increases muscular endurance
02Enhances muscular strength and power
03Improves endurance time-trial performance
04Enhances attention, alertness, and mood
05Increases fat oxidation and thermogenesis
06Reduces perceived exertion during exercise

Chemical Forms

Recommended
  • Caffeine anhydrous (capsules/tablets — most studied)
  • Natural caffeine from coffee or green tea
  • Caffeine gum (faster buccal absorption for acute use)
Avoid
  • Caffeine powder (bulk) — extreme overdose risk
  • High-sugar energy drinks (added sugar negates benefits)
  • Proprietary blends with undisclosed caffeine amounts
Expert Note

Capsules produce the greatest ergogenic effect in studies

Protocol

Amount
3 - 6 mg/kg body weight
Frequency
as needed (pre-exercise)
When
45-60 min before exercise

Condition-Based Dosing

Endurance performance (cycling, running, swimming)
3 - 6 mg/kg, 45-60 min before exercise
Strength and power training
3 - 6 mg/kg, 30-60 min before training
Cognitive performance and alertness
1 - 3 mg/kg (100-200 mg) as needed
Fat oxidation and weight management
3 - 5 mg/kg before fasted cardio or throughout the day
Low caffeine sensitivity / habitual users
Consider 5-7 day washout before key events

Safety & Limits

Upper Safe Limit
400 mg/day for healthy adults (FDA general guidance)
Cycling
Safe for continuous use

Contraindications

Anxiety disorders (may exacerbate symptoms at ergogenic doses)
Cardiac arrhythmias or uncontrolled hypertension
Pregnancy (limit to ≤200 mg/day; some guidelines advise avoidance)
Insomnia or sleep disorders (avoid within 8-10 hrs of bedtime)
Children and adolescents (no established safe ergogenic dose)
Concurrent stimulant medications (additive cardiovascular effects)
GERD / peptic ulcer (increases gastric acid secretion)
Seizure disorders (may lower seizure threshold at high doses)

Synergies

L-Theanine

Smooths caffeine's stimulant edge; reduces jitters while preserving focus

Creatine

Complementary performance pathways: caffeine for CNS, creatine for ATP

Taurine

Combined CAF+TAU improves anaerobic capacity and reaction time over either alone

Avoid Combining With

  • ✕Sleep (caffeine's half-life of 5-6h severely disrupts sleep quality)
  • ✕Adenosine buildup (chronic use upregulates adenosine receptors — tolerance)
  • ✕Anxiety-prone individuals (may worsen anxiety at ergogenic doses)
  • ✕Melatonin (caffeine counteracts melatonin's sleep-promoting effects)
Updated 4/15/2026