The heat goes on

With the Rio Olympic and Paralympic Games only a year away work has been ongoing for some time on how best to prepare the New Zealand athletes for the temperatures they might face in Brazil.
In conjunction with High Performance Sport NZ, the various sports have been discussing the best methods needed to cope with conditions which will be served up in the Rio winter.

Leading work in this area is HPSNZ performance physiologist Julia Casadio, who says the term  “winter” should not be interpreted as comparable to the New Zealand winter and that the period from June to September should perhaps be more accurately known as “the dry season”. 

“During the time period of the Olympics (August 5-21) Rio can get cold fronts of between 19-24degC, but also temperatures of up to 35degC,” she explains. “If we get a cold front then temperature will not be an issue, but we need to plan for both.”

Julia explains that for endurance athletes, performance impairments due to heat stress start at 27degC.

“In such conditions, the core temperature of the body rises and in response, blood flow is redistributed from the core and working muscles to the periphery of the body where it can cool from the evaporation of the sweat. As a result the body has to work harder to meet the demands of the exercise, heart rate soars and an early onset of fatigue occurs.”

The sporting action is based across four zones in Rio with each hub throwing up its own climatic distinctions. Temperatures at the Barra hub – site of the Olympic and Paralympic Village - can typically range in August from anywhere between 19-34degC. The Copacabana zone – which includes sports such as rowing, canoe-kayak, triathlon and sailing - benefits from a cooling sea breeze with temperatures typically between 18-29degC. The Maracana zone – home to athletics – will be in the 20-31degC range and the most inland zone Deodoro – home to equestrian, hockey and rugby sevens - could see temperatures soar to 36degC.

With heat levels on average rising in Rio for the month of September, New Zealand's Paralympic team could be exposed to even more extreme temperatures when the Paralympic Games action starts on 7 September. 

For Julia and her team, preparing for the conditions the athletes face is likely to be critical.

 “If there is a sport where heat could impair on performance we’ll help put together a heat acclimatisation strategy with them and this could take several forms.”

One commonly used strategy to adapt to the heat is for athletes to spend time training in the heat chamber housed at AUT Millennium on Auckland's North Shore for anywhere between four to seven days in a row. Athletes can workout on a number of different pieces of cardio equipment including treadmill, bike and rowing erg at a range of different temperatures and varying humidities.
“To achieve adaptation it is important the athletes get that core temperature up to 38-38.5degC,” she says. “This will allow the athletes to feel more comfortable in the heat both physiologically and mentally.”

Another commonly used method is a 30-minute sauna post-exercise. With the core temperature already high, Julia says the last 10 minutes of the half-hour can be “extremely uncomfortable” as the heart-rate soars to levels of moderate-intensity exercises despite just sitting in the heat.

However, she adds: “It is an amazing example of how the heat can impact upon an individual. It is also a nice tool to use because saunas are readily available the world over.”
Some sports will opt for their athletes to spend time pre-Olympics and pre-Paralympics in a warm environment to gain heat adaptation with North America and Spain two possible destinations to achieve this ambition.

Yet while research has shown that the best adaptation period of four to seven days can last for up to two weeks there are a number of other questions which Julia is currently pondering.
“What hasn't been widely proved yet is the amount of fatigue sustained by training in the heat,” she explains. “A week training in the heat can be fatiguing and we wouldn't want to send the athletes into competition at less than 100 per cent. We need to balance this and make sure we time things right.”

Julia admits that size and shape can impact on the body's ability to adapt in the heat with those of greater body mass having a greater capacity to store heat.

However, whichever strategy is adapted, she insists acclimatising to the heat will not be a waste of time whatever the conditions faced in Rio.

“The cool thing about training in the heat is the adaptations which occur can improve aerobic performance in a hot environment or a cool environment, so the work won't be lost and an athlete will gain some benefit,” she adds.