Over 6 days in the heart of the Belize Jungle, 2 brave athletes were faced with the hardest challenge, both physically and mentally that they had ever had to confront. The Jungle Survival Marathon entailed 6 days of survival training in the jungle followed by a 200km race across similar terrain to eventually escape and reach the final checkpoint – this meant at least 10 hours of running a day! The two athletes brave enough to take on this challenge were the Dhiman brothers, Gary and Steve who courageously took to the challenge after a brotherly rivalry led to a bet – neither of them was going to back down and look where they ended up!

Gary and Steve reached out to the Environmental Extremes Lab to seek some support in how to best prepare themselves for the climatic conditions they would experience out in Belize. This is where the University of Brighton MSc students came in – myself and a team of fellow MSc Applied Physiology students, supervised by Dr Neil Maxwell, were responsible for the delivery of a series of heat acclimation sessions with the aim of helping Gary and Steve cope better with the conditions they would see during the race. The temperatures were expected to reach 33ºC with an average relative humidity of 80%; it was sure to be a hot and sticky week!

The initial session involved a lactate threshold for both athletes, to highlight any differences in fitness between them both as this could throw an extra consideration into their race strategies. Further to this initial session, a pre acclimated Running Heat Tolerance Test (HTT) was completed to assess how well each of the brothers initially coped with the hot and humid conditions. This would also help us to determine if the heat acclimation sessions had worked as we’d expect to see some good improvements to the measures we’d be taking. Physiological Strain Index (PSI), calculated using core temperature and heart rate, was one of the main indicators we used to show the athletes how well they were coping with the heat, alongside sweat rate; the latter critical show they could manage their rehydration strategy. We also measured perceptual indicators of effort (ratings of perceived exertion) and heat (thermal comfort and thermal sensation) – all valid and reliable measures we often use in our Environmental Lab sessions. As an additional test to satisfy the Jungle Marathon organisers, we carried out a 12 lead ECG prior to testing to look for any cardiac arrhythmias. 

A few weeks later came the five heat acclimation sessions which we based on a strong base of research evidence around heat alleviation strategies from the EEL lab, not least directed towards ultra-marathons in the heat. The main principle of these sessions were to get the brothers hot and keep them hot for the 90-minute session! This was achieved by a mixture of running, cycling, step ups and sitting down for short periods using an isothermic model, where core temperatures was targeted to exceed 38.5°C. During these sessions, it was really important for the team to educate the brothers on the risks of heat illness and the signs and symptoms they may either feel in themselves or see of each other while they were in the jungle, as it would be crucial for keeping them safe while battling their way through the challenging conditions. Following the final acclimation session, it was time for the post HTT. The results of this test indicated both brothers had become more heat acclimated to the conditions similar to what they would be faced with in Belize, which was a positive result before flying out for a week of survival training before the commencement of the Jungle Survival Marathon itself. Importantly, there were good perceptual adaptations, reduced sensations of fatigue and evidence of behavioural thermoregulatory adaptations.

On the 2nd of March the race began. Gary and Steve went into the challenge knowing they were as prepared as they could be, even if their navigation knowledge needed a bit of brushing up!

After their first day making their way across the jungle, Gary and Steve found themselves wondering if they had bitten off more than they could chew and started to doubt if they would be able to make it to the next checkpoint. Despite this, after some encouragement from their jungle guide and some tough love from each other, they continued their journey. In spite of an amazing performance over several days, sadly, they reached day 5 and 120km into the race when the brothers were unable to continue – only 4 others made it to the finish line (with one of them having the advantage of being ex-special forces!) which proves how much of a challenge the Jungle Survival Marathon really is!

Gary and Steve raised over £6500 for both the Great Ormond Street Hospital and Medical Aid for Palestinians, both organisations close to their heart. Undoubtedly a once in a lifetime opportunity for all who were involved, and for myself and the students involved we were extremely grateful to have been able to work alongside them in their preparations. It has to be said, while we tried to maintain our professionalism in delivering this Environmental Extremes Lab Consultancy Service, Steve and Gary were great entertainment and provided plenty banter! This has provided an excellent chance for us to put our environmental physiology skills into action while also working on those softer skills too that are essential for the world of work!

Well done Gary and Steve! 

By Becca Salter 

MSc Applied Sport Physiology Student, University of Brighton

Environmental Extremes Lab Support Team: Becca Salter (lead) Bobbi Deegan, Jack Blenkarn, Rob Walton, Andy Knowles, James Sinfield, Maddy Hamlett, Amelia Monkcom, Vanisha Majevadia, Luke Row and Dr Neil Maxwell