Freediving seems counterintuitive to survival. Hold your breath. Plunge beneath solid ice. Swim nearly two football fields through near-total darkness at temperatures that numb the body in seconds. Yet New Zealand freediver Ant Williams has set a world record for the longest distance swum under ice, covering 182 metres in Iceland's Lake Stiflisdalsvatn, where water temperatures hovered around 0.2 degrees Celsius.
What separates Williams from other athletes is not superior lung capacity or an exceptional physique. Williams states: "If you don't train your mind, it will sabotage you," which he believes is the key to his success. Before becoming a world-record holder, Williams was a sports psychologist working with elite athletes like MotoGP riders and big-wave surfers, spending years helping them push past fear and stay calm under pressure. That background shapes everything he does in the water.
Feeling like a fraud coaching athletes in dangerous sports when he had never felt what it was like to risk everything in the moment, Williams opted for freediving rather than skydiving or rock climbing. During his record-breaking ice dive, somewhere in the second half, a strange calm set in. His breathing reflex disappeared, his movements became fluid, and his mind cleared. The panic faded, replaced by what he'd discovered: the elusive 'flow state'.
The body's ancient bargain with the deep
Freediving success depends on understanding what humans share with seals, whales and dolphins: the diving reflex, a set of physiological responses to immersion that overrides basic homeostatic reflexes and optimises respiration by preferentially distributing oxygen stores to the heart and brain, enabling submersion for an extended time.
The diving reflex is an instant, automatic reflex activated when our sensory receptors detect wetness. When they detect wetness, the trigeminal nerve sends information to the brain, which immediately triggers bradycardia. The body then enters oxygen and blood conservation mode, with the heart, brain, and lungs as top priority receivers.
This isn't optional. When lungs cannot breathe as they usually do, anxiety kicks in, the brain enters panic mode, and adrenaline is released. As the heart rate soars, oxygen consumption reaches maximum levels. The trick is to override the body's inbuilt natural reaction to breathe, using the mammalian diving response as an ally.
Cold water intensifies the reflex. Upon facial contact with water and breath holding, the human heart rate lowers to around 10 to 25 per cent almost immediately, and up to 50 per cent in trained individuals. The effects of bradycardia are enhanced when the temperature of water decreases. Under ice at near-zero temperatures, the effect becomes profound.
Blacking out is a constant risk
Prolonged breath-holding, especially after hyperventilation, can lead to a dangerous drop in blood oxygen levels, causing loss of consciousness before the urge to breathe becomes overwhelming. This can occur even in shallow water and is a leading cause of drowning in freedivers.
Williams navigates this edge with meticulous preparation. In the moments before his world record attempt, he focuses on "time minus one," the two or three minutes before it happens, unpacking what's happening in those moments. For Williams, the mental preparation outweighs physical conditioning.
Williams had been competing in the sport of freediving for 17 years before his world record attempt, showing the sort of investment required. Some people see only a guy who turned up in the Arctic Circle, broken a world record and flew back home, while others think he must have some sort of death wish.
When he eventually surfaced with his world record, he reported coming up feeling like he didn't even need a breath, with no signs of discomfort or fatigue, perfect air management and technique on point. It was a reminder that freediving is won or lost in the mind.