The urge to breathe isn't about needing oxygen—it's about discomfort with carbon dioxide. That desperate gasping feeling during hard efforts? It's your brain reacting to CO2 buildup, often before oxygen becomes an issue. Train your tolerance to CO2, and you train your capacity to stay calm under respiratory stress.
Breath hold training systematically builds this tolerance, improving athletic performance and developing mental resilience in the process.
Understanding CO2 Tolerance
The Breathing Trigger
What drives the urge to breathe:
Primary trigger: Rising CO2 levels, not falling O2
The sensation: Chest pressure, air hunger, discomfort
Performance impact: Early breathing urge = inefficient respiration
The opportunity: CO2 tolerance is trainable
Athletic application: Better tolerance = calmer performance under respiratory load
Why Tolerance Matters
For athletic performance:
Breathing efficiency: Less reactive breathing patterns
Composure maintenance: Calm despite respiratory stress
Performance extension: Working longer before distress
Mental resilience: Discomfort tolerance transfers broadly
Recovery: Better breathing patterns during recovery
Individual Variation
CO2 tolerance varies:
Baseline differences: Some naturally tolerate more than others
Training state: Better athletes often have better tolerance
Anxiety connection: Anxious individuals often have lower tolerance
Modifiable: Everyone can improve with training
Basic Breath Hold Practice
The BOLT Score
Measuring your tolerance:
BOLT: Body Oxygen Level Test
Method: 1. Normal breath in, normal breath out 2. Hold after the exhale 3. Time until first definite urge to breathe 4. Resume normal breathing (shouldn't be gasping)
Interpretation: - Under 10 seconds: Low tolerance, significant room for improvement - 10-20 seconds: Below average - 20-30 seconds: Average - 30-40 seconds: Good - Over 40 seconds: Excellent
Improving BOLT
Basic training approach:
Exhale holds: Hold after normal exhale, shorter but specific to CO2
Inhale holds: Hold after normal inhale, longer but different stimulus
Frequency: Multiple short holds better than few long holds
Recovery: Always recover fully before next hold
Progression: Gradually extend hold times
Beginner Protocol
Starting safely:
Week 1-2: - 5-10 exhale holds daily - Hold until first clear urge to breathe - Full recovery between holds
Week 3-4: - 10-15 holds daily - Slightly extend past first urge - Maintain calm recovery
Week 5+: - Progress based on BOLT improvement - Add walking holds - Integrate with training
Advanced Techniques
Table Training
Structured hold progressions:
CO2 Tables: Fixed holds with decreasing rest - Example: 8 rounds of 90-second hold with rest decreasing from 2:00 to 1:00
O2 Tables: Increasing holds with fixed rest - Example: 8 rounds with holds increasing from 60 to 120 seconds, 2:00 rest between
Caution: Advanced techniques require careful progression
Walking Holds
Dynamic breath holding:
Method: Hold breath while walking at normal pace
Target: Walk comfortably, don't strain
Progression: Gradually extend walking distance during hold
Benefits: Integrates movement with breath control
Safety: Stop hold well before distress
Exercise Integration
Holds during training:
Warm-up holds: Brief holds during dynamic warm-up
Recovery holds: Holds during rest periods
Cool-down holds: Longer holds as part of cool-down
Never during max effort: Don't hold during high-intensity work
Nasal Breathing Under Load
Related training:
Principle: Training with mouth closed improves efficiency
Method: Nasal-only breathing during moderate training
Progression: Gradually increase intensity while maintaining nasal breathing
Benefit: Improves CO2 tolerance and breathing efficiency
Safety Considerations
Fundamental Rules
Never compromise safety:
Never in water: Breath holding in water can cause shallow water blackout—extremely dangerous
Never while driving: Obvious impairment risk
Never alone for advanced work: Partner or supervision for longer holds
Stop on warning signs: Dizziness, tingling, visual disturbance
Always recover fully: Before next hold or activity
Contraindications
Who should avoid or modify:
Cardiovascular issues: Consult doctor first
Respiratory conditions: Asthma, COPD need medical guidance
Pregnancy: Not recommended
Seizure history: Avoid breath holding
Recent surgery: Wait for clearance
Progressive Approach
Build gradually:
Start conservative: Shorter holds than you think you need
Increase slowly: Small progressions over weeks
Listen to body: Some days are not good for holds
Regular assessment: Track BOLT score for progress
Athletic Applications
Pre-Competition
Using holds before performance:
Calming effect: Brief holds can reduce anxiety
Arousal regulation: CO2 slightly increases, then calm on release
Breathing reset: Establishes efficient pattern
Mental preparation: Practice being comfortable with discomfort
During Competition
Strategic application:
Recovery breathing: Efficient breathing between efforts
Composure maintenance: Tolerance prevents panic breathing
Pacing awareness: Better sense of respiratory state
Clutch moments: Calm breathing under pressure. See clutch performance.
Sport-Specific Uses
Tailored application:
Endurance sports: Better breathing efficiency for sustained effort
Combat sports: Composure under respiratory stress
Swimming: Obviously relevant; improved comfort with restricted breathing
Team sports: Recovery between plays
Precision sports: Calm breathing for accuracy
Integration with Other Practices
Breath Holds and Meditation
Combined practice:
Pre-meditation: Brief holds can settle the mind
During meditation: Gentle holds as concentration anchor
Post-hold calm: The quiet after a hold can deepen practice
Box breathing: Includes hold components
Breath Holds and PMR
Sequenced practice:
PMR first: Relaxation before breath work
Holds from relaxed state: More comfortable, often longer
Deep relaxation: Combined practice can reach deep calm
Breath Holds and Cold Exposure
Advanced integration:
Common combination: Often practiced together
Similar mechanisms: Both stress hormesis
Careful approach: Don't combine if new to either
Expert guidance: Advanced combination work needs supervision
Building Your Practice
Week 1-4: Foundation
Establishing the basics:
Daily BOLT test: Morning measurement for tracking
10-15 exhale holds daily: Basic tolerance building
Nasal breathing awareness: Begin noticing mouth breathing habits
No exercise integration yet: Learn holds alone first
Week 5-8: Development
Expanding practice:
Walking holds: Add movement to holds
Warm-up integration: Brief holds in training warm-up
Increased daily volume: More holds if recovering well
Continue BOLT tracking: Should see improvement
Week 9+: Application
Full integration:
Training integration: Strategic holds during training
Competition application: Use skills under pressure
Maintenance volume: Fewer holds to maintain tolerance
Continued development: Advanced techniques if appropriate
Measuring Progress
BOLT Tracking
Regular assessment:
Frequency: Weekly morning test
Conditions: Same time, same state
Progression: 5-second improvement per month is good progress
Plateau: Normal; adjust training if extended
Performance Correlation
Noticing real-world effects:
Breathing comfort: Less distress at same intensity
Recovery speed: Faster return to normal breathing
Composure: Calm despite respiratory challenge
Endurance: Sustained effort before breathing distress
Key Takeaways
- Urge to breathe is about CO2—not oxygen deprivation
- Tolerance is trainable—systematic practice improves response
- BOLT score tracks progress—regular measurement shows improvement
- Safety first—never in water, never while driving, stop on warning signs
- Start conservative—short holds, full recovery, gradual progression
- Athletic application—better breathing efficiency, composure under stress
- Integration with training—holds during warm-up, recovery, cool-down
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