Caffeine and Training: Dosage, Timing, and How to Avoid Tolerance

Caffeine is the most consumed drug in the world. And for good reason: it works. For training, it’s one of the few ergogenic aids with decades of solid evidence.

But there’s a right and wrong way to use it. Let’s break it down.

How Caffeine Works

In the Brain

Caffeine blocks adenosine - the neurotransmitter that makes you feel tired.

Without caffeine:
Adenosine accumulates → You get tired → Sleep

With caffeine:
Caffeine blocks adenosine receptors
→ Brain doesn't "perceive" tiredness
→ You stay alert

In the Body

Physiological effects:

Central nervous system:
✅ Increases alertness
✅ Reduces perception of fatigue
✅ Improves focus and concentration

Muscles:
✅ Increases calcium release (contraction)
✅ Improves fiber recruitment
✅ Reduces perception of pain/effort

Metabolism:
✅ Increases fat oxidation
✅ Elevates metabolic rate 3-5%
✅ Mobilizes fatty acids

What Science Confirms

Strength Performance

Meta-analysis Grgic et al. (2018):
- 1RM: +2-3%
- Reps to failure: +6-10%
- Power: +3-5%

For strength training: Caffeine allows more reps and more weight. Over time, that means more gains.

Endurance/Cardio

Endurance studies:
- Time to exhaustion: +10-20%
- Running/cycling performance: +2-4%
- Perceived exertion: Significantly reduced

Fat Burning

Real but modest effect:
- Metabolism increase: 3-5%
- In 24h with 200mg: ~50-100 extra calories
- Not magic, but helps

Note: Caffeine doesn’t “burn fat” directly. It slightly increases calorie expenditure and mobilizes fat for use as energy. You still need a deficit.

Ideal Dosage

Dose by Body Weight

Scientific recommendation: 3-6mg per kg of body weight

Person weighing 155lbs (70kg):
- Low dose: 210mg (3mg/kg)
- Medium dose: 280mg (4mg/kg)
- High dose: 420mg (6mg/kg)

Person weighing 175lbs (80kg):
- Low dose: 240mg
- Medium dose: 320mg
- High dose: 480mg

Person weighing 130lbs (60kg):
- Low dose: 180mg
- Medium dose: 240mg
- High dose: 360mg

Fixed Dose (Simplified)

If you don’t want to calculate:

Beginner/sensitive: 100-150mg
Moderate use: 200-300mg
Tolerant: 300-400mg
Maximum recommended: 400mg/day

Sources and Equivalencies

Drip coffee: 80-100mg per cup (8oz)
Espresso: 60-80mg per shot
Strong coffee: 120-150mg per cup
Common pre-workout: 150-300mg
Pill/capsule: Exact dose
Black tea: 40-70mg
Green tea: 30-50mg
Energy drink (Red Bull): ~80mg

Advantage of pills/capsules: Precise dose. Coffee varies a lot.

Perfect Timing

Pre-Workout

When to take: 30-60 minutes before training

Why?
- Peak blood concentration: 30-60 min
- Effect lasts 3-5 hours
- Entire workout covered

The Training Window

Timeline after consumption:
0-15 min: Absorption starting
30-60 min: PEAK effect ← Ideal for training
60-180 min: Strong effect
180-360 min: Effect diminishing
6h+: Still 50% in system

Cutoff Time

Golden rule: Don’t consume caffeine after 2pm (or 6-8h before bed)

Why?
Caffeine half-life: 5-6 hours
This means:
- 200mg at 2pm → 100mg at 8pm → 50mg at midnight
- Even "little" caffeine affects sleep quality

If you train at night: Either train without caffeine, or adjust dosage so it doesn’t affect sleep.

Tolerance: The Real Problem

What Is Tolerance

With daily use, your body adapts:

Week 1: 200mg = MAXIMUM ENERGY
Week 4: 200mg = energy is ok
Week 8: 200mg = almost nothing
Week 12: 200mg = just to avoid withdrawal

What happens: Your brain creates MORE adenosine receptors to compensate for the blockade.

Signs of High Tolerance

✅ Need more caffeine for same effect
✅ Get headaches without caffeine
✅ Irritability without coffee
✅ Extreme fatigue without consumption
✅ Need coffee just to feel "normal"

How to Keep Caffeine Effective

Strategy 1: Strategic Use (Not Daily)

Instead of:
Every day: 300mg

Do:
Heavy training days: 200-300mg
Light/rest days: 0-100mg or zero

Result: Tolerance stays low

Strategy 2: Cycle Caffeine

Simple protocol:
8-12 weeks: Normal use
1-2 weeks: "Washout" (no caffeine)
Repeat

During washout:
- First 2-3 days are tough (withdrawal)
- Headache, fatigue, irritability
- Then it normalizes
- Sensitivity returns to normal

Strategy 3: Variable Doses

Monday: 300mg (heavy training)
Tuesday: 150mg
Wednesday: 0mg
Thursday: 200mg
Friday: 300mg (heavy training)
Saturday: 100mg
Sunday: 0mg

Result: Never develop total tolerance

Withdrawal: What to Expect

If you use caffeine daily and stop:

Day 1-2:
- Headache (very common)
- Intense fatigue
- Irritability
- Difficulty concentrating

Day 3-5:
- Symptoms decrease
- Energy starts returning
- Headache goes away

Day 7+:
- Back to normal
- Sensitivity restored

Tip: To reduce withdrawal, decrease dose gradually instead of stopping cold turkey.

Week 1: Reduce 25%
Week 2: Reduce another 25%
Week 3: Reduce another 25%
Week 4: Zero or minimum

Caffeine and Sleep

The Real Impact

Caffeine is the #1 enemy of quality sleep.

Even without "feeling it":
- Reduces deep sleep time
- Increases nighttime awakenings
- Decreases overall quality
- Affects even those who "sleep well with coffee"

Journal of Clinical Sleep Medicine study: Caffeine 6 hours before bed still reduces sleep by 1 hour.

Rules to Protect Sleep

✅ Last dose by 2pm (or 6-8h before bed)
✅ Don't exceed 400mg/day total
✅ Avoid caffeine to "compensate" for poor sleep
✅ If training at night, prefer without caffeine

Remember: Poor sleep > pre-workout effect. Don’t sacrifice 8h of recovery for 1h of energized training.

Side Effects

Common (Dose-Dependent)

With high doses (400mg+):
- Anxiety
- Tremors
- Rapid heartbeat
- Restlessness
- Irritability

In Sensitive People

Even with low doses:
- Palpitations
- Sweating
- Gastrointestinal discomfort
- Insomnia (even in the morning)
- Anxiety

If you’re sensitive: Start with 50-100mg and increase gradually.

When to Avoid Caffeine

❌ Heart problems
❌ Anxiety/panic
❌ Uncontrolled high blood pressure
❌ Pregnancy (limit to 200mg)
❌ Chronic sleep problems
❌ Use of certain medications

When in doubt, consult a doctor.

Caffeine vs Pre-Workout

Commercial Pre-Workout

What it usually contains:
- Caffeine (150-300mg) ← This works
- Beta-alanine (tingling) ← Works for endurance
- Citrulline (pump) ← Modest effect
- Creatine ← Works (but doesn't need to be pre)
- "Proprietary blend" ← Hidden doses
- Dubious ingredients ← Marketing

DIY Pre-Workout (Best Cost-Benefit)

Make it yourself:
- Coffee or caffeine capsule: 200mg
- Creatine: 5g (optional, can take any time)

Cost: $0.25-0.50 per dose
vs
Commercial pre-workout: $1-2 per dose

You’re paying a lot mainly for caffeine with flavor and tingling.

Frequently Asked Questions

”Coffee or capsule?”

Coffee:
✅ More antioxidants
✅ Pleasant ritual
❌ Imprecise dose
❌ Can cause digestive issues

Capsule:
✅ Exact dose
✅ No calories
✅ More practical
❌ Without the pleasure of coffee

For training: Capsules are more practical. For day-to-day: coffee is fine.

”Can I take coffee and pre-workout?"

You can, but be careful with total dose.
Pre-workout (200mg) + Coffee (100mg) = 300mg
That's already a moderate-high dose.

Risk of caffeine overdose if you don't calculate.

"Does caffeine break a fast?"

Black coffee without sugar: ~3-5 calories
Technically doesn't break the fast
Caffeine can even enhance fat oxidation while fasting

"Every day or just training?"

Ideal: Only on heavy training days
Why: Maintains sensitivity

Acceptable: Every day with moderate doses
But: Tolerance will develop

"What’s the safe maximum?”

FDA recommends: ≤400mg/day for healthy adults
That equals: ~4 cups of coffee
More than that: Risks increase

Recommended Protocol

For Those Who Don’t Use Caffeine Regularly

Weeks 1-2:
- 100mg on heavy training days
- See how you respond

Week 3+:
- Increase to 150-200mg if tolerated well
- Maximum 3-4x per week
- Keep caffeine-free days

For Regular Users (High Tolerance)

Option 1: Reset
- 2 weeks without caffeine
- Accept the withdrawal
- Return with lower doses

Option 2: Gradual reduction
- Week 1: Cut 25%
- Week 2: Cut another 25%
- Weeks 3-4: Minimum or zero
- Return with strategic use

Smart Long-Term Use

Rules:
1. Maximum 4-5x per week
2. Vary doses (not always maximum)
3. At least 1 day/week without
4. Cycle every 2-3 months
5. Respect sleep

Final Summary:

Aspect	Recommendation
Dose	3-6mg/kg or 200-300mg
Timing	30-60 min before training
Limit	400mg/day, until 2pm
Frequency	Not daily, strategic
Tolerance	Cycle or vary doses
Form	Coffee or capsule

Caffeine works. It’s cheap. It’s proven. But use it wisely to maintain the effect and not sacrifice your sleep.

The best pre-workout in the world isn’t worth a bad night’s sleep.

References:

Grgic J, et al. “Effects of caffeine intake on resistance exercise: A dose-response meta-analysis.” Eur J Sport Sci. 2018.
Goldstein ER, et al. “International society of sports nutrition position stand: caffeine and performance.” J Int Soc Sports Nutr. 2010.
Drake C, et al. “Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed.” J Clin Sleep Med. 2013.
Pickering C, Kiely J. “Are the current guidelines on caffeine use in sport optimal for everyone?” Sports Med. 2019.