Advice on holding your breath in training

We are in a world where we are constantly pushing the boundaries of swimming performance, the one area we are all striving to improve is our underwater and breath-holding ability.

In a race, swimmers only spend a few seconds underwater and breath-holding for prolonged periods can cause shallow water blackout.

We’ve produced the following guidelines and facts about holding your breath in training.

Please contact us at swimmingtalent@swimming.org if you have any questions about swimmers holding their breath in training, or any other aspect of swimming coaching.

What is shallow water blackout?

  • Hyperventilation (consciously or unconsciously) reduces carbon dioxide (CO2) levels in the blood as it is exhaled at an increased rate.
  • As the breath-hold continues, oxygen (O2) levels in the blood drop.
  • Usually an increase in CO2 in the blood would trigger the desire to breathe and the swimmer would end the breath hold attempt. Due to the hyperventilation, CO2 levels are too low to trigger this, and the urge to breathe doesn’t occur as early.
  • This combined with low O2 levels can cause the swimmer to go unconscious.
  • Once unconscious, the body will react by initiating a breath. However, whilst submerged, the lungs will fill with water, and if immediate assistance does not occur death by drowning will can occur.
  • If the swimmer is rescued they should be immediately taken to hospital.
  • Secondary (delayed) drowning can happen when water is inhaled into their lungs causing inflammation. This can happen hours to days afterwards with the air sacs of the lungs swelling and preventing oxygen entering the blood. If a swimmer feels ill after prolonged underwater breath holding they should seek medical advice urgently.

Safety guidelines for holding breath in training

  1. Do not practise prolonged breath-holding. We should not ignore the need to breathe.
  2. You should not encourage underwater breath-holding. However, if practised, the rule of thumb for safety is:
    One breath-hold
    One time only
    One length maximum
    Do not repeat
  3. Never hyperventilate.
  4. Always be supervised – never swim alone
  5. Repetitive breath-holding increases risk. If breath-holding underwater, a buddy must be next to you tapping you on your shoulder so you can signal that you are OK. Their total focus needs to be you and your safety. They should never breath-hold with you. Do not rely on lifeguards as it is difficult to observe someone who is in difficulty from above the water.
  6. Lung-training devices can be bought to train inspiratory muscles on land.

Useful resources

Use the following links to read more about coaching swimmers and the dangers of breath holding in swimming.

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