Overheating is a problem for many athletes, but wheelchair athletes can take on an even more extreme version of this challenge. Many of these athletes battle spinal cord injuries and are therefore “unable to sweat and control their blood flow below the level of their lesion,” says Katy Griggs, who studies the thermoregulatory responses of wheelchair athletes. The ways these Paralympians “can self-cool from outside sources are important,” she told Ars.
Because of these thermal regulation issues, Team USA wheelchair rugby players (all but two with spinal cord injuries) jokingly refer to themselves as “reptiles.” But their attempts to cool themselves off during the 2016 Paralympic Games, which start this week in Rio de Janeiro, are deadly serious.
Trainers generally pay close attention to athletes’ temperatures and the possibility of heat illness, but they must be extra vigilant when it comes to wheelchair athletes, as self-monitoring can be more difficult. For example, wheelchair users cannot always see the color and amount of their own urine, making it more difficult to use as a measure of hydration. (And to be more alert to dehydration or overhydration, Team USA staff are now using refractometers to measure gravity in urine.)
Jim Murdock, the athletic trainer/medical coordinator for the US wheelchair rugby team, has tried just about every innovation to keep his athletes cool. Ice vests have been one of the most effective cooling techniques for improving the performance of athletes with spinal cord injuries, but Murdock has found them to be of limited use to the rugby players he trains.
“The problem is that the vests don’t fit them,” he explained to Ars. “[After all] every man fits his chair differently. It would be labor intensive to tailor these types of garments for each athlete.
Another commonly used strategy is the local cooling of body parts. It is not always practical for wheelchair athletes to submerge the entire body in water (cryotherapy), as some able-bodied athletes do. Researchers have looked at immersing hands and feet in cold water or using cooling devices on specific body parts, although this may be more appropriate after exercise.
But again, this is a no-go for the Team USA wheelchair rugby team. These athletes usually wear gloves or tape on their hands, and they can’t afford to let their hands go numb. It is also cumbersome and time consuming to remove shoes from feet that are usually reclined in a wheelchair.
Driving a truck around an inflatable pool to use as a cooling pool can work – the Paralympic team has had to do it – but it’s also tricky. And that plan is complicated in Rio by the fact that some athlete facilities lack ice machines, freezers and air conditioning.
So what to do? Low-tech remedies are best right now. A mainstay for keeping rugby players cool is a cold beach towel, applied for 10-15 minutes during physical exertion. A spray bottle filled with cool water is another.
Yet another is equally no-nonsense: the humble slushie. “Everyone loves the slushies,” said Murdock. Whether they’re made from Gatorade or something else, there’s a strand of research that supports the effectiveness of this strategy. For example, this article in the magazine Sports medicine suggesting that ice slurries may work to lower core temperatures and improve performance through effects “on brain temperature, internal thermoreception and sensory responses.”
The drive to optimize recovery and performance doesn’t mean wheelchair athletes aren’t resilient and flexible. But able-bodied athletes have many resources and relatively little attention is paid to athletes with physical limitations. “There aren’t many things for athletes in wheelchairs,” Murdock noted. And among this small amount of research, few studies take into account the widely varying abilities and conditions of these athletes.
Even if some cooling techniques haven’t changed much since Murdock himself was an athlete, monitoring must be sophisticated these days. Two members of the wheelchair rugby team representing the US in Rio have diabetes, and as Murdock noted, “massive thermal swings are not good for them.” Therefore, team trainers have implemented data collection systems to track the status of the athletes. Among other things, it is being investigated whether athletes with a higher cardiovascular condition are less susceptible to overheating.
The scientific evidence on how different cooling techniques affect core/skin temperature remains mixed. With so many variables — timing, duration, body part, temperature, device weight, type of activity, nature of the impairment — research is complex, and previous studies of athletes with spinal cord injuries have tended to be small-scale. Translating findings from a research setting into practical application remains a hurdle.
Researchers, trainers, and athletes aren’t the only ones concerned about overheating; Sports organizations are also aware of the problem. Eron Main, CEO of the International Wheelchair Rugby Federation, explained to Ars that a temperature of 26.2–21.6°C is required for matches.
“In fact, we usually require tournament organizers to make sure there’s a power supply on every bench so teams can plug in fans,” he said. “A few teams have even brought small chest freezers to the bank to keep ice vests cold.”
Both on and off the field of play, athletes may wear cooling neck collars, vests and other items of clothing as long as they match the uniform colors and do not pose a safety risk.
Given the intensity of the sport that was first dubbed “murderball,” let’s hope temperatures aren’t an issue in Rio.