It’s a workout loved by the rich and famous, and seemingly every fitness guru and influencer is giving it a whirl on TikTok.

However, the physical aftermath of hot yoga, favoured by the Beckhams and Drew Barrymore, might not be as appealing as content creators claim.

Hot yoga, otherwise known as Bikram yoga, sees health-conscious participants exercising via poses akin to traditional yoga but in balmy temperatures.

The humid environment is the differentiating factor and results in considerable sweating, with teachers touting the hot conditions as the secret to weight loss and improved fitness, among other rewards.

Devotees of hot yoga, which was spread in the west by Bikram Choudhury and aims to recreate India‘s scorching temperatures, hold their bodies in challenging poses, leaving them dripping with sweat but exhilarated at the culmination of an intense workout.

A typical session lasts 90 minutes in a room heated to 40°C (105°F), with 40 per cent humidity.

Despite TikTok brimming with content creators showing the exercise as part of their self-care routine, Dr Veronika Matutyte told Femail how hot yoga can raise red flags from a medical perspective.

While the consequences may vary, the aftermath could include fatality.

John F. Kennedy’s nephew died  in 2018 from a heart attack while in a hot yoga studio, and the workout could potentially be to blame, according to his cousin.

Christopher Lawford, the son of Patricia Kennedy and Peter Lawford, worked as a Hollywood actor and member of the legendary Rat Pack with Frank Sinatra. He was 63 when he died.

His cousin, former US Rep Patrick J Kennedy, told the New York Post that the workout ‘must have been too much for him at that point.’

‘I believe the death of JFK’s nephew, while the official cause may be debated, underscores a critical and often overlooked risk of hot yoga that I find deeply concerning’, Dr Veronika Matutyte said.

She continued: ‘I believe hot yoga places extreme stress on the cardiovascular system. It transcends dehydration even though that’s undeniably a major contributing factor.’

Content creator’s appear unaware of the potentially harmful consequences, with @charinlondon scoring over 1000 views on her hot yoga TikTok while influencer Sarah Batista recorded herself in various poses, writing: ‘Today was extra hot’.

However, nestled among the glamorous posts, fitness influencer Katie Gallagher warned her followers that the 90-minute hot yoga class was the hardest workout she’s ever done.

TikTok content creator @charinlondon racked up over 1000 thousand views on her video of a hot yoga class

Christopher Kennedy Lawford (seen in California in 2017) died in 2018 after suffering from a heart attack in a yoga studio

Dr Veronika continued: ‘I’ve seen how the intense heat forces the heart to work overtime to cool the body. This isn’t just a mild increase in heart rate but a significant physiological demand [and] coupled with the electrolyte imbalances caused by profuse sweating, [it] can create a perfect storm.’

‘In such cases, hot yoga can act as a trigger, potentially leading to cardiac arrhythmias, heat stroke, or other serious and even fatal complications. 

‘This tragic case, regardless of the final determination, serves as a stark reminder for all of us that hot yoga isn’t simply a flexibility workout – but a significant physiological challenge. 

‘I feel strongly that this point is often lost in the marketing and hype surrounding the practice. 

‘While the deep stretching and mental focus can be beneficial for some, I find that the risks particularly to the cardiovascular system are real, significant, and shouldn’t be underestimated. 

The medical expert added: ‘I can’t emphasise this enough. Don’t assume that just because you’re young or feel healthy, you’re immune to these risks. 

‘The heat can affect all of us, and it’s always better to err on the side of caution. I’ve seen the consequences of underestimating these risks and I can attest that they can be devastating.’

While certain studies point to the benefits of hot yoga, a 2015 study found that the sport raises body temperatures and heart rates to ‘dangerous levels’.

Actress and television host Drew Barrymore (pictured) is reportedly a big fan of the intense yoga variety 

Emily Quandt, who led the University of Wisconsin-La Crosse study with John Porcari, said: ‘The dramatic increases in heart rate and core temperature are alarming when you consider that there is very little movement, and therefore little cardiovascular training, going on during class.’

Twenty healthy volunteers – seven men and 13 women between the ages of 28 and 67, took part, and all regularly practised Bikram yoga, meaning they were familiar with the 26 standard poses.

Before starting a session, each volunteer swallowed a core body temperature sensor and put on a heart rate monitor to wear during the class.

Researchers recorded body temperature before the class started and then at 10-minute intervals throughout the session and heart rate every minute.

The findings showed the heart rate fluctuated throughout the class, depending on the pose difficulty.

Body temperature steadily increased throughout the 90-minute class in both men and women.

The average body temperature for men was 39°C (103°F) and 38°C (102°F) for women.

A male participant scored the highest core temperature of 40°C (104°F), while seven volunteers’ temperature reached 39°C (103°F).

Scientists noted that, while none of their volunteers’ exhibited signs or symptoms of heat intolerance, their body temperatures can pose a danger for some people, given that the risk for heat-related illness, such as heat stroke, increases at 40°C (104°F).

Dr Quandt said though excessive perspiration experienced by people doing Bikram yoga is often cited as a benefit because it releases toxins, the results of the new study showed sweating was insufficient to cool down the body.

She advised three ways to improve the safety of Bikram yoga classes – duration, temperature, and hydration.

Dr Quandt noted that participants started to experience dangerous core temperatures around 60 minutes into the session.

Therefore, shortening the length of the typical class to just an hour could help minimise the risk of heat intolerance.

In addition, lowering room temperatures may appear obvious, but would help reduce the risk, Dr Quandt said.

Furthermore, the medical expert said hydration lies at the heart of the Bikram yoga controversy.

Teachers often designate just one water break during classes, though many acknowledge that students should hydrate as required throughout their class.

However, some Bikram enthusiasts believe that by minimising their water intake, they augment the mindful aspects of the practice, with fewer water breaks decreasing the potential for mental distraction.

Dr Porcari said: ‘Nothing is gained from withholding water in any setting. Exercise leaders must actively encourage hydration, particularly when classes take place in extreme environments like those seen in Bikram yoga classes.’

He said Bikram yoga teachers must be familiar with essential science principles surrounding exercise, including a clear understanding of the physiology of the thermo-regulation.

‘Knowing the risks associated with things like blood pooling and vasodilation, as well as the signs and symptoms of heat-related illness, is absolutely essential,’ he added.

Dr Cedric Bryant, chief science officer at the American Council on Exercise, which commissioned the study, agreed.

He said: ‘Bikram teachers should recognise that participants’ thermoregulatory systems will be challenged in this environment. It is essential that they are aware of the early warning signs of heat intolerance.’

Signs of intolerance can include cramps, headache, dizziness, and general weakness.

The researchers concluded: ‘Exercising in hot and humid environments – whether inside a studio while practising Bikram yoga, or outside running during the warm months – can place participants at risk for heat-related illness, especially if those individuals do not adequately hydrate before, during, and after exercise.

‘Not only does it take time for the body to acclimatise to activity performed in hot and humid environments, proper hydration is crucial.’

‘Given the popularity of Bikram yoga and its proven benefits, it is likely here to stay,’ said Dr Bryant. ‘It is our job to make sure it is done safely.’