Research by UK and Australian scientists shows for the first time that short-term heat training can significantly boost athletic performance without jeopardising an athlete’s immune system. Ahead of the Rio 2016 Olympics, the University of St Mark & St John-led study could pave the way for more effective training for elite athletes preparing to compete in hot conditions.
In the study, published online in the journal Frontiers in Physiology, heat training over 18 days enhanced participants’ cycling performance – increasing speed by more than nine per cent - without challenging their immune systems.
Heat training is often considered risky because of the considerable stress it puts on the body, which could make an athlete susceptible to coughs, colds or flu before a big event. While previous research has demonstrated the benefits of heat training on performance, this is the first study to examine the impact on an athlete’s immune system.
Male athletes were split into three groups: a heat training group, a thermo-neutral training group and a control group. All participants took part in cycling time trials in the laboratory. The heat and thermo-neutral training groups then undertook seven further 40-minute cycling training sessions over 18 days. While the thermo-neutral group trained in average temperatures and humidity, the heat training group exercised in 35 degree heat and 70 per cent humidity.
While both groups improved more than the control group, the cyclists that underwent heat training were nine per cent faster by the end of the study. The heat training helped these athletes to reduce their core temperature and heart rates while training. Crucially, blood tests showed no compromise to their immune systems.
Research group leader, Professor Andrew Edwards of the University of St Mark and St John, said: “With Rio currently experiencing above-average temperatures and high humidity, Olympic athletes will need to be well prepared to perform in hot conditions. For Team GB, these conditions will be considerably hotter than most athletes are used to. With the 2018 Commonwealth Games and Qatar 2022 World Cup on the horizon, heat training is becoming increasingly important for elite athletes.
“Infections caused by over training pose a real risk to athletic performance and for elite athletes, busy training programmes limit the time available for strategies such as heat training. There is a delicate balance between pushing an athlete’s body to adapt to the heat, without negatively impacting on his or her immune system. Research like ours is helping to identify the right level of training to achieve optimum results, which could pave the way for elite athletes to prepare for sporting events in hotter climates.”
This research was carried out by a team from the University of St Mark & St John in Plymouth, James Cook University in Cairns, Australia and the Australian Institute of Sport. The study adds to Professor Edwards’ internationally recognised body of work relating to performance in heat. Professor Edwards was recently invited to deliver a presentation on heat training and fluid intake for sports performance at the International Society of Sports Nutrition (June 2016) at Clearwater Beach, Florida, USA.
Top tips for optimising athletic performance in the heat, by Professor Andrew Edwards, University of St Mark & St John:
- A few weeks before the big event, carry out interval training sessions in hot conditions. Our research suggests seven 40-minute sessions over 18 days would be ideal.
- Cool your body as quickly as possible after heat training. Research has shown that this reduces your perception of how hard you have worked and limits tiredness without reducing the benefits of training. Drinking a cold drink, like a slushy, works as well as dunking your body into a cold bath and is a lot more pleasant!
- During exercise you should drink to satisfy thirst rather than seek to immediately replace all the fluids you lose through sweat. Sweat loss can be up to 1,200ml an hour, but the human body can only tolerate around 500ml fluid intake an hour. So ensure you are well hydrated before training or competing, then drink according to thirst during the event and rehydrate properly afterwards. Overhydration is potentially more damaging than moderate dehydration.
Click to find out more about the Faculty of Sport & Health Sciences at the University of St Mark & St John.
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