What happens when you hold your breath?

Without its most fundamental and basic need your body starts to fight. The breath center in your brain frantically triggers spasms in the chest, your lungs and muscles start to tingle before the burning starts and the pressure in your brain builds.

For Aleix Segura Vendrell, World Champion of Static Apnea, as the struggle takes grip he eases into it. “You’re suffering, so you have to set these mini targets, 15 seconds, then the next and the next”, after this point he is capable of another 5 minutes.

swimmer in black and white blowing bubbles in pool


  • Delving Into Our Outer Limits


Static Apnea is a breath holding discipline, a unique sport in which athletes submerge themselves face down in water for as long as possible without a breath of air. Typically practised by freedivers or swimmers, static apnea is performed on land to hone their skills and condition their lungs for time in the ocean or in competitions.

For Aleix Segura Vendrell, World Champion of Static Apnea, his life started in the water, spearfishing and chasing after fish on the northern coast of Spain. To support his freediving he began to practice static apnea to enhance his lung capacity. An architect by training, Segura who practices static apnea in his spare time, setting the still unbroken Guinness World Record in 2016, of 24 minutes and 3 seconds.

Aleix Segura Vendrell, World Champion

Physically you’re is suffering so at some point, it needs to have a point. For me it’s my time in the ocean.

“Some people do freediving just for the competition itself, but it’s very easy to get burned out. Physically your brain is suffering so at some point, it needs to have a point. For me it’s my time in the ocean”.  

Practice for Segura takes place as part of an amateur club in local swimming pools. Athletes lie face down in the water, repetitive plunges, each for longer and longer, are the technique to achieving longer breath holds. “We always go to our limits. Everytime we’re in competition or practice, we go to our maximum attempt” says Segura. “The real limit is hypoxia, but our feelings of suffocation come from the increase of CO2”.

Feelings of suffocation can start minutes into the session for practiced divers as carbon dioxide builds, followed by contractions in the chest and larynx, pain in the lungs and chest, spreading to the rest of the body, confusion and then loss of vision. Blood pressure peaks during the exertion at roughly 200/300 mmHg, over double the normal heart rate. However staying perfectly still is important to minimise energy loss. “We learn how to detect dangerous signs, but we lose perception of time, and control. There are so many small signs it becomes tricky. That’s why we have so many safety personal, in case we fail to judge it. Really it’s just the fear of failure in the competitions. Whereas in the ocean one small miscalculation and it’s all over!”.

freediver in a black and white image


  • Coming Up for Air


Naturally slim, Segura’s slighter frame doesn’t carry as much weight as his larger competitors. With a smaller frame, this also translates to a reduction in lung to mass ratio; a physical advantage in the sport. However, through training alone, Segura has increased the elasticity and capacity of his lungs to contain an estimated 8.5litres from the average 7 litres. “It’s not superhuman, it’s just a matter of training. We can always take it further and further”.

Professor Nevill of the University of Wolverhampton has studied the patterns of improvement in static apnea. “Like all sports there’s a period when people can learn tricks to hold onto. But these tricks run out and they start to reach a plato”, the scientist observes. “There is an absolute limit. People can’t go on and continue to hold their breath forever”.

For Segura the search of peace within the ocean pushes himself further, “it’s your limit for that day, in that dive, with that preparation. So it’s not that we have a permanent limit, we move it forward through training.  When I’m training I disconnect and think about nothing, I lose perception of time, it’s meditative” .


Aleix Segura Vendrell is the World Champion in Static Apnea, setting the Guinness World Record in 2016 with 24 minutes and 3 seconds.

Watch the video of the incredible feat here.

Dr Alan Nevill is a Professor of Sport at the University of Wolverhampton has studied the biostatistics of athletes in a range of fields. Find out more about his research here.

Read More