PB in the heat? It's all in the mind...

By Guest Blogger | 5 Minute Read

Jonny Brownlee is a legend of triathlon. A two-time Olympic medalist with European, Commonwealth and World Championship titles to his name.

But, for many, the abiding image of the 29-year-old is being unceremoniously dumped by his brother, Alistair, over the Cancun World Series finish line in a desperate bid to win the 2016 world title.

Jonny needed victory in Mexico. Despite Alistair’s best efforts, Jonny finished second, leaving him four points behind overall winner Mario Mola. Heat exhaustion had sent Jonny zig-zagging down the Mexican finishing chute. Determination proved no match for Jonny’s rise in core temperature.

Brownlee readily admits racing in the heat is a weakness of his so he’s physically adapting to the hotter climes of the 2020 Tokyo Olympics by creating a heat chamber at his Leeds home – more precisely, in his conservatory.

"It’s four electric heaters, a treadmill and a stationary bike," Jonny told The Times’ journalist Sam Munnery earlier this year.

Regular chamber stints make Jonny’s body more 'heatproof', catalyzing a series of physiological adaptations conducive to racing hard in the heat - including increased blood-plasma volume, lower core temperature, increased sweat rate, and many more.

 

Desert image
Image by Andrew Deslauriers via Unsplash (Copyright free)

 

But, according to Stephen Cheung, professor of Environmental Ergonomics at Brock University, Canada, Jonny and his acclimatizing brethren will also be mentally adapting their brains to performing in the heat.

"Many studies focus on the physical aspect of training and racing in the heat, less so how it affects the central nervous system and the psychology," Cheung explains. "That’s an oversight because if we know what’s happening in our minds, we can make interventions to improve."

Cheung, who was sporting a broken foot after a climbing accident when we met him at July’s Science & Cycling Conference – an annual meet of scientists, exercise physiologists and WorldTour support staff – cited several areas that triathletes, cyclists and runners can focus on when mentally adapting to the heat. But before prescription, let’s understand the role the mind plays in hemorrhaging power when it’s hot.

 

Dampen the alpha wave

"Lars Nybo is key to our knowledge base," says Cheung, Nybo’s Professor of Integrative Physiology at the University of Copenhagen.

During his PhD, Nybo had subjects undertake a 60-minute time-trial in normal environmental conditions. They repeated the time-trial in temperatures above 35°C (95°F). 

"Not surprisingly, their power output dropped in the heat," adds Cheung.

But what role did the mind play?

Nybo took a multitude of measurements, including brainwaves via an EEG (electroencephalogram) to understand the notion of arousal. To do this, he examined alpha and beta waves and discovered that the alpha-beta ratio increased. This means the brain is less responsive and aroused when hot.

Explanation required. When executing a task, brain activities observed through electric waves resulted in different frequency bands. The main ones are alpha, beta, theta and delta.

Studies show that alpha and beta waves are related to alertness and cognitive capacity. They also show that if the ratio of alpha to beta waves rises, physical output is reduced.

"Interestingly, our study group also looked at the effects of high temperature on muscle recruitment," adds Cheung. "We asked whether we can recruit as many muscles in the heat compared to normal climes? The subjects took a pill [to measure core temperature] and we heated them up to a very uncomfortable 39.5°C (103.1°F). We discovered that the brain was less able to recruit muscles in that heat."

 

Runner in the sun
Image by Joshua Sortino via StockSnap (Copyright free) 

 

Cheung also showed how RPE (Rate of Perceived Exertion) rose during the heat, which was derived from a higher brain temperature and reduced brain activity, resulting in greater rates of fatigue and reduced times to exhaustion.

All this links back to Tim Noakes’ Central Governor Model of Fatigue and Samuele Marcora’s Psychobiological Model of Fatigue, where, in a reductionist way, the brain judges how hard you can exercise while protecting itself.

"One of the key things it takes into account is heat build-up, plus factors like glucose levels and breathing rate," says Cheung. "You utilise feedback from past sessions that feeds forward to determine your pacing strategy."

 

Talk your way faster

"Heat is a danger sign. This is both ‘real’ and ‘perceptual’. And it’s the latter where a battery of psychological tools come in," explains Cheung.

Dr Martin Barwood [of Leeds University] had trained runners to run as fast as they could for 90 minutes in the heat. He tested them on day one and two weeks later.

In-between, one group undertook a range of psychological skills training, from goal-setting to self-talk and arousal regulation. The control didn’t.

Come the second test, the control group exhibited no improvement in performance. The psychologically trained group could run on average 1-1.5km further in the heat – despite showing no difference in physical strain.

Cheung repeated a similar study in the heat, though using the tool he felt was the most effective: self-talk.

"The mental skills group increased their time to exhaustion over the control group," says Cheung. "Incredibly, one subject improved by 26%." 

Cheung also discovered that psychological tools improved decision-making by raising mental tolerance to heat. In a sporting scenario, that’d mean pacing more effectively or cornering more efficiently.

 

The happy hormone

You can also walk the chemical route to (legally) perform better in the heat by manipulating dopamine levels (the happy hormone) in the brain.

Cheung cited an experiment by Professor Bart Roelands of Brussels University where subjects were administered 20mg Ritalin (yes, the drug used to treat children with Attention Deficit Hyperactivity Disorder (ADHD)) or a placebo.

‘‘Power output rose in the heat over a control group," says Cheung. "And while core temperature rose, thermal discomfort dropped."

How? Ritalin slows down the decay of dopamine in the brain. This is important because dopamine plays a key role in the thermoregulatory centre of the brain. In essence, Ritalin made the brain less susceptible to the warning signs of heat.

 

BrainImage by Jesse Orrico via StockSnap (copyright free)

 

This was supported by a study undertaken by Professor Romain Meeusen, also of Brussels University, who was funded by WADA (World Anti-Doping Agency) to examine the impact of Ritalin in the heat.

"Meeusen had cyclists ride a one hour time-trial in the heat with and without Ritalin," Cheung explains. "In the Ritalin trial, where dopamine levels were higher, riders could generate a higher wattage than under placebo. They could also tolerate a higher core temperature."

Cheung also noted that the noradrenaline-inhibitor drug Reboxetine raised performance in the heat for similar neuromuscular/core temperature reasons as Ritalin. That pharmaceutical intervention is clearly why WADA have begun paying Ritalin, in particular, interest.

"I’d not recommend either," says Cheung.

There are more natural methods of raising dopamine. Dopamine is synthesised in the body, so you can’t simply down a dopamine shot, but you can eat foods that provide the nutrients you need to produce dopamine. These include the amino acids L-theanine and tyrosine, which can both be obtained from protein-rich foods like lean chicken and tuna.

Cheung suggested it takes five to seven days to mentally adapt to the heat through physiological acclimatization.

It all goes to show that Jonny Brownlee’s northern 'hot house' is not only physically beneficial for the heat and humidity of Tokyo, but psychologically, too.

And as it’s arguably the mind that separates elite endurance athletes, his DIY heat chamber could deliver the one medal missing from his CV: Olympic gold.

This blog was written by sports journalist James Witts, the author of Training Secrets of the World's Greatest Footballers.

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