One of Netflix’s ‘best ever’ documentaries leaves viewers in tears after learning about one of the deadliest activities in the world

An 'addictive and alarming' Netflix documentary has had viewers in tears and branding it one of the 'toughest' watches on the platform.

There's no shortage of films or documentaries on Netflix that make us emotional, and sometimes it's those true stories that really hit home.

Other times viewers can get so invested in characters, that the storyline becomes so much more than a piece of fiction.

But viewers have branded this Netflix documentary showcasing one of the most dangerous activities in the world, their hardest watch yet.

And it was even nominated for the Sports Emmy Award for Outstanding Long Sports Documentary.

It makes for captivating watch. (Netflix)

Titled The Deepest Breath is one of its originals, the nearly two-hour-long documentary follows the story of Italian champion Alessia Zecchini and Ireland’s Stephen Keenan in the freediving world.

The official description of The Deepest Breath from Netflix reads: “Bonded by their love of freediving, a record-setting champion and a heroic safety diver try to make history with a remarkable feat, ready to risk it all.”

After watching the gripping documentary, fans were quick to share their opinions on X.

Freediving is one of the most dangerous activities. (Netflix)

One said: "The Deepest Breath doc is wild.

"Free diving might just be the most extreme extreme sport out there."

Another said: "This afternoon I watched The Deepest Breath on Netflix.

"As a former dive instructor who tried a bit of free diving, I found it very emotional.

"One of my instructors, Nico, died while freediving back in 1998.

"RIP to all those lost to the sea."

A third added: "It’s an incredible documentary about free diving and a beautiful love story. I wasn’t expecting that ending!

"congratulations on the nomination for The Deepest Breath!"

Freediving is a dangerous extreme sport where competitors attempt to dive to mind-boggling depths underwater and hold their breath until resurfacing without using any scuba gear.

In the documentary, Zecchini hopes to set a new world record and she is assisted by safety diver Keenan.

This challenging dive is 184 feet below the Red Sea and features a 85-foot-long tunnel.

During the dive, the Italian must swim from one safety rope to the other, on either side of the tunnel, where Keenan is set to meet her.

But as you can imagine, it's not all smooth-sailing.

On Rotten Tomatoes, the documentary has an impressive 96 percent audience score.