The description of freediving – an extreme sport that involves diving underwater while holding your breath – is already scary enough, but the video above will have you holding your own breath in subconscious solidarity.
Taken from Laura McGann's Netflix documentary The Deepest Breath, the clip shows Alessia Zecchini attempting a world record freedive, starting beside a boat on the water's surface and following a thin line down into the increasingly murky depths.
Zecchini makes it down and back to the surface, but watching her journey is uncomfortable to say the least.