Before the crowd floods the arena and a single punch is thrown, many combat athletes are already inflicting stress on their bodies.

Many mixed martial arts fighters practice weight cutting, which involves rapidly shedding kilograms the day before a fight by dehydrating the body in order to qualify for a smaller weight class.

After weighing in lighter, fighters can then rehydrate to gain weight just before a fight and compete with a size advantage over their opponent. 

With thousands expected to attend the Ultimate Fighting Championship in Perth this weekend, the practice is in the spotlight.

The Western Independent spoke to Perth fighter Kye Bicknell as he moved between a sauna and a bed of towels to encourage sweating the day before his fight.

“Feels like you’re dying,” Mr Bicknell says.

“That last push is always the worst.

“You don’t feel like you’ve got much in you, it’s a horrible feeling.”

Mr Bicknell was aim to cut almost 6kgs in preparation for his official weigh in later that day, having already lost several in the week prior.

Mr Bicknell trains with assistant coach Luke Johnstone at the Kickass MMA gym, who says the practice is deeply embedded in combat sports culture.

“Everybody has to make weight,” he says.

“We might both be walking around at 77 or 80kgs the week before, but we both know we’re going to weigh in at 70.”

After athletes are weighed, they race to gain the weight back before the fight to remain competitive.

“The more you cut, the harder it is to rehydrate the brain,” Mr Johnstone says.

“Your muscles absorb water quickly, but the brain is the last thing to come back.”

For Perth teenager Jessica Lindsay, weight cutting proved fatal.

In November 2017, the 18-year-old died in hospital four days after collapsing during training at a Forrestdale gym.

She was preparing for an amateur Muay Thai bout, undertaking a weight cutting program that included running in a sweat suit, sauna sessions, hot salted baths and a strict diet.

In her final week she consumed up to 7.5 litres of water in one day, reducing her intake to nothing.

She collapsed hours before her weigh-in after running in a car park on a 31 degree day wearing layers of clothing. 

A coronial inquest later found she died from multiple organ failure caused by heat stroke. 

Jessica’s death prompted significant scrutiny of the sport, with the WA Combat Sports Commission developing a strategy to discourage the practice.

The Commission’s research identified health risks such as decreased cardiovascular function, decreased kidney function and increased risk of brain injury.

Matthew Cahill, an exercise physiologist and a former MMA practitioner, says weight cutting can be terrible for health.

“A lot of the water is pulled from your blood, meaning the blood gets much thicker and significantly harder for the heart to pump around the body,” he says.

“The brain also has a lot of water around it, so there are going to be significant impairments in how well it carries out its processes.

“Then you combine that with potentially being hit in the head repeatedly and it can be quite worrisome.”

The risks aren’t only physical; Mr Cahill says weight cutting can also impact the psychology of the fighter.

“Your body’s in a state of starvation while you’re still trying to perform at a really high level,” he says.

“You’re constantly hungry, constantly thirsty, and your entire life revolves around working hard without fuelling yourself – it’s a huge psychological burden.”

The WA Combat Sports Commission collected data from 426 competitors and 15 events in 2017, finding 50 fighters gained more than 10 per cent of their body weight in the 24 hours between weigh-in and fight night.

Even with a successful rehydration period, fighter Kye Bicknell says a bad cut still leaves its mark come fight night.

“I’d say when a cut goes wrong, more than 60 per cent of the time you notice it affecting your performance negatively, which is massive” he says.

Mr Bicknell believes the sport itself needs structural reform, pointing to the large gaps between weight classes as the biggest problem. 

“The gap between lightweight and welterweight is huge,” he says.

“There just needs to be something more in between.”

For now though, his focus is clear: weigh-in is just hours away and kilos still need to be shed.

“That’s all I’m thinking about right now,” he says.

“Just need to get to Saturday.”