Breathing Deceleration Study: Magnitude of Deceleration and Training Strategies

Breathing is a necessary action in swimming, but it is also a speed killer. Research shows that each freestyle breath causes an instantaneous deceleration of approximately 0.05–0.08 m/s, equivalent to a time loss of 0.05 seconds. In a 100-meter freestyle with 30 breaths, this theoretically adds up to 1.5 seconds—but in reality, elite swimmers can reduce this loss to under 0.5 seconds. What’s the secret?

1. Why Does Breathing Cause Deceleration?

The three main reasons for breathing-induced deceleration:

1. Head lift: The head leaves its normal horizontal position, causing the lower body to sink and increasing overall drag
2. Excessive body rotation: To get the mouth above water, the body rotates extra, disrupting the streamlined position
3. Interrupted stroke rhythm: The stroke taken during the breath is often weaker than a normal stroke

2. Quantitative Research Data

According to a 2018 study by the Australian Institute of Sport (AIS):

Breathing Type	Speed Loss	Suitable Swimmers
Good breathing	0.03–0.04 m/s	Elite
Moderate breathing	0.05–0.06 m/s	Advanced
Poor breathing	0.08–0.12 m/s	Beginner

3. 5 Key Techniques to Reduce Breathing Deceleration

Technique 1: Minimize Head Position

When breathing, the head only needs to rotate, with the eyes looking to the side rather than upward. The lower eye remains in the water, with the waterline passing through the midline of the top of the head.

Test: When swimming, others should only see one eye and one nostril above the water, not your entire face.

Technique 2: Coordinate with Body Rotation

Breathing should be a “natural result of body rotation,” not an additional movement. A rotation angle of about 45 degrees is sufficient to meet breathing needs.

Technique 3: Exhale Fully Underwater

Many swimmers only begin exhaling at the moment they lift their head, causing most of the breathing time to be spent on “exhaling” rather than “inhaling.”

Correct approach: Exhale steadily and continuously while the head is underwater, so that only inhalation is needed the moment the head breaks the surface.

Technique 4: Don’t Slow Down the Stroke During Breathing

The stroke taken during a breath often unconsciously slows down, which is the main cause of deceleration.

Training method: Deliberately focus on the power of the breathing stroke, making it identical to the non-breathing stroke.

Technique 5: Timing of Head Return

The timing of the head returning to the water after breathing is critical:

• Too early: Insufficient inhalation
• Too late: The body has already started the next stroke, causing rhythm disruption
• Optimal: The head returns to the water just as the hand enters the water

4. Breathing Characteristics by Stroke

Freestyle

• Breathing deceleration: 0.05 m/s
• Room for improvement: Large
• Training focus: Head position, rhythm

Breaststroke

• Breathing deceleration: 0.10–0.15 m/s (breaststroke breathing is the most demanding)
• Room for improvement: Moderate
• Training focus: Breathing speed (quick in, quick out)

Butterfly

• Breathing deceleration: 0.08–0.12 m/s
• Room for improvement: Moderate
• Training focus: Don’t lift the head too high, synchronize breathing with the second kick

Backstroke

• Breathing deceleration: Almost none
• But a regular breathing rhythm is needed to avoid lactate buildup

5. Hypoxic Training

Hypoxic training improves the body’s tolerance to oxygen deprivation by reducing the frequency of breaths:

Training Example 1: 3-5-7-9 Ladder

• 25m × 4 reps
• Rep 1: Breathe every 3 strokes
• Rep 2: Breathe every 5 strokes
• Rep 3: Breathe every 7 strokes
• Rep 4: Breathe every 9 strokes

Training Example 2: No-breath 25m

• Complete 25m without breathing
• 8 reps, 30 seconds rest between sets
• Trains breath-holding capacity

Training Example 3: 5-3-5-3 Alternation

• Within a 50m, breathe every 5 strokes for the first 25m, then every 3 strokes for the last 25m
• Trains adaptation to changing oxygen demands

6. Precautions

Although hypoxic training is effective, it carries risks:

• Never do it alone (it is recommended to have a partner or coach supervising)
• Avoid surfacing to breathe after prolonged breath-holding (risk of shallow water blackout)
• Those with cardiovascular disease or asthma should consult a physician

7. Breathing Strategies in Competition

50m Freestyle

• 0–15m: No breathing (underwater dolphin kick)
• 15–35m: Breathe every 2 strokes
• 35–50m: Option to not breathe or breathe every 3 strokes

100m Freestyle

• First 50m: Breathe every 2 strokes
• Second 50m: Breathe every 2 or 3 strokes
• Final 15m: Option to hold breath and sprint

8. Quantifying Training Progress

Monthly testing:

• 25m no-breath time trial: Men’s target under 13 seconds
• 50m breathing vs. no-breathing time difference: Should be within 1.5 seconds
• 100m breathing vs. no-breathing time difference: Should be within 3.5 seconds

Conclusion

Breathing deceleration cannot be completely eliminated, but it can be minimized. A swimmer with refined technique can be only 1 second slower even with 40 breaths compared to not breathing; a swimmer with poor breathing technique may be 3 seconds or more slower. Training your breathing to be “almost imperceptible” is an essential skill for advanced swimmers.

Related Reading

• Swimming Breathing Technique: Pros and Cons of Side Breathing and Bilateral Breathing
• Not Breathing in the Final 5 Meters of a Sprint: Physiological Basis and Training Strategies
• Breathing Rhythm in Open Water: Techniques for Maintaining Long-Distance Performance
• Swimming Breathing Pattern Training: Building Tolerance for 3-Stroke and 5-Stroke Breathing