Caffeine

Mechanisms:

• Adenosine receptor antagonist (blocks sleepiness signals)
• Increases catecholamine release (dopamine, norepinephrine, epinephrine)
• Enhances calcium release in muscle fibers
• Reduces perceived exertion during exercise
• Increases fat oxidation

Key studies:

• Goldstein et al. (2010): ISSN position stand confirming ergogenic effects
• Grgic et al. (2020): Meta-analysis showing strength and power benefits
• McLellan et al. (2016): Review of cognitive enhancement effects

Effect sizes:

• Endurance performance: 2-4% improvement
• Strength/power: 3-7% improvement
• Reaction time: 5-10% faster
• Perceived exertion: Reduced by 5-6%

Limitations:

• Tolerance develops with chronic use
• Individual genetic variation (CYP1A2 gene)
• Can impair sleep if taken too late
• Withdrawal symptoms with cessation

Performance dosing:

• 3-6 mg/kg body weight (200-400mg for most people)
• Take 30-60 minutes before training
• Higher doses (6mg/kg) not necessarily better - more side effects
• For cognitive tasks, lower doses (1-3 mg/kg) often sufficient

Timing:

• Half-life is 5-6 hours (varies by genetics)
• Avoid within 8-10 hours of bedtime
• Morning training: take upon waking
• Afternoon training: be mindful of sleep impact

Managing tolerance:

• Cycle off periodically (1-2 weeks every few months)
• Or use only for key training sessions
• Lower baseline consumption preserves acute effects

Common mistakes:

• Too much too late (ruins sleep)
• Building tolerance through constant use
• Not accounting for coffee's caffeine content
• Expecting miracles - it's a 2-5% edge, not a transformation

Known side effects:

• Anxiety and jitteriness (dose-dependent)
• Sleep disruption if taken too late
• Increased heart rate and blood pressure
• GI distress in some individuals
• Dependency and withdrawal headaches

Contraindications:

• Anxiety disorders (may exacerbate)
• Heart arrhythmias (consult doctor)
• Pregnancy (limit to <200mg/day)
• Sleep disorders

Withdrawal symptoms:

• Headache (most common)
• Fatigue and irritability
• Difficulty concentrating
• Peak at 24-48 hours, resolve within a week

Genetic variation:

• CYP1A2 gene affects metabolism speed
• "Slow metabolizers" more sensitive to side effects
• 23andMe and similar tests can identify this

Ideal for:

• Endurance athletes
• Strength/power athletes (pre-workout)
• Anyone needing cognitive boost
• Morning exercisers
• Shift workers (strategic use)

Should skip or limit:

• Those with anxiety disorders
• People with sleep issues
• Caffeine-sensitive individuals
• Pregnant women (keep under 200mg/day)
• Those with heart conditions (consult doctor)

Best responders:

• Caffeine-naive individuals (haven't built tolerance)
• Fast metabolizers (CYP1A2 gene)
• Endurance athletes (largest performance benefit)

What to measure:

• Training performance (times, weights, reps)
• Subjective energy and focus (1-10 scale)
• Sleep quality (if taking later in day)
• Resting heart rate

Tools:

• Sleep tracker to monitor sleep impact
• Training log for performance
• Heart rate monitor

Signs it's working:

• Increased alertness within 30-60 min
• Better workout performance
• Enhanced focus and motivation
• Reduced perceived effort

Signs of overuse:

• Need it just to feel "normal"
• Diminishing effects at same dose
• Sleep quality declining
• Anxiety or jitteriness

Coffee (most common source):

• Espresso: ~63mg per shot
• Drip coffee: ~95mg per 8oz
• Cold brew: ~200mg per 8oz

Caffeine pills (precise dosing):

• Nutricost Caffeine - 200mg pills, cheap
• Smarter Vitamins Caffeine - With L-theanine for smoothness
• ProLab Caffeine - Simple, tested

Pre-workout options:

• Most pre-workouts contain 150-300mg caffeine
• Check labels - some have excessive amounts
• Pills give more precise control

What to avoid:

• Energy drinks with excessive sugar
• "Proprietary blends" hiding caffeine amount
• Combining multiple caffeine sources unknowingly

Coffee:

• Home brewed: $0.10-0.30/cup
• Coffee shop: $2-5/cup

Caffeine pills:

• Bulk pills - ~$0.05/dose
• With L-theanine - ~$0.15/dose

Pre-workout powders:

• Budget: $0.50-1.00/serving
• Premium: $1.50-2.50/serving

Cost-per-benefit assessment:

Caffeine is absurdly cheap for its effect size. Even high-quality caffeine pills cost pennies per dose. Coffee is more expensive but provides ritual and additional compounds.

Researchers:

• Andy Galpin, PhD - Performance dosing protocols
• Layne Norton, PhD - Evidence-based supplementation

Practitioners:

• Andrew Huberman, PhD - Timing and optimization protocols

Reddit communities:

• r/caffeine - Dedicated caffeine discussion
• r/nootropics - Caffeine stacking discussions
• r/fitness - Pre-workout timing discussions

Common positive reports:

• "Night and day difference in morning workouts"
• "Much better focus for deep work"
• "Endurance sessions feel easier"
• "L-theanine combo removes the jitters"

Common complaints:

• "Tolerance built up fast"
• "Affected my sleep more than I realized"
• "Get anxious at higher doses"
• "Withdrawal headaches are real"

Pairs well with:

• L-theanine - Smooths out jitters, enhances focus (100-200mg)
• Morning training - Aligns with cortisol rhythm
• Fasted cardio - May enhance fat oxidation
• Pre-competition - Save for important events to maximize effect

Timing considerations:

• Wait 90-120 min after waking for max cortisol benefit (Huberman protocol)
• Or take immediately if training early
• Stop 8-10 hours before bed minimum

Stacks with:

• L-theanine (2:1 ratio theanine:caffeine)
• Creatine (conflicting data - may blunt some effects)
• Beta-alanine (complementary mechanisms)