Flaring temperatures during the games may not only hamper the athletes’ performance—it could gravely harm them.
Olympic athletes represent the pinnacle of human achievement in physical fitness. Whether it’s hurling javelins or hurtling across the track, Olympians offer us a vista at what peak performance, life-long dedication, discipline and athleticism can accomplish. Yet, for all their accolades and nigh-limitlessness in strength and endurance, these athletes are still human. This year, as the 2020 Olympics continue to take place, temperatures in Tokyo, Japan will continue to hover around a sweltering 30oC (86oF). While this may not seem like a lot at first glance, such heat can have detrimental effects on not just the athletes’ performance, but—more importantly—their health and well-being.
To raise awareness about these potential health hazards, engineers at Hexagon have used simulation to explore how an athlete competing in the 10,000 m race would fair under such grueling weather conditions. The results show that even if the 10,000 m events took place after sunset, athletes still run the risk of a range of health issues including cramps, nausea, heart palpitation and heat stroke. While the simulation focused on the men’s 10,000 m race, these results are relevant to all sporting events, particularly those requiring extreme feats of strength, durability and endurance.
Hexagon engineers assess the dangers athletes face when competing in the heat of the Tokyo Games.
“There’s been much discussion about the decision to hold the Games in the Tokyo summer,” said Dr. Keith Hanna, Hexagon’s vice president of marketing for design and engineering. “These simulations show the extreme conditions that athletes will be competing under. Athletes are accustomed to pushing themselves to the limits and these simulations show how racing conditions impact performance as well as the risks undertaken when the human body is pushed to extremes. What’s most interesting is the small margins of change—a couple of degrees shift in temperature can have a huge impact, so it’s only a matter of time to see whether we edge over that 39oC core temperature ‘tipping point’.”
Temperature Sensitivity in Humans
As climate change ravages the world, global temperatures continue to rise at alarming rates. Tokyo’s average temperature, in particular, has soared by nearly 2.86oC since 1900. As such, the Tokyo 2020 Olympics are considered one of the hottest games in history, with some dubbing it “the rings of fire.”
The average human body’s temperature is 37oC (98.6oF), but our sensitivity to body temperature variation is such that even a 0.6oC increase in body temperature (37.6oC) is considered “feverish.” As temperatures increase, health risks increase, along with cognitive decline—the mood and stress levels, the ability to focus and complete complex tasks, as well as short-term memory, are all hampered by heightened body temperatures. At a body temperature of 40oC (104oF)—just three degrees higher than the average body temperature—the risk of heatstroke increases dramatically.
Additionally, humidity plays a crucial role in athletes’ performance. Under normal conditions, the body produces sweat which then evaporates from the skin, allowing the body to cool down. However, with high humidity levels, the sweat does not readily evaporate like it’s supposed to. As a result, the body continues to heat up and produces even more sweat. Left unchecked, this can lead to dehydration, cramps and other heat-related health problems. During strenuous physical labor (ergo, the Olympics), these risks are exacerbated as exercise further increases body temperature.
“The main factors leading to heatstroke in athletes are the ambient temperature of the performance area, the percentage humidity in the air, and the actual movement of the air (which affects the ‘feels like’ temperature),” explained Hanna. “The problem in Tokyo is the humidity. The air is already saturated and moisture can’t evaporate, so our natural way of regulating body temperature doesn’t work. In a situation like this, any kind of intense physical exertion will put a great deal of strain on the body.”
A Two-Pronged Simulation
For modeling to be as accurate as possible, engineers at Hexagon ran two different simulations. In the first simulation, dubbed ‘average conditions’, they set the air temperature to 27oC (80.6oF) with a humidity level of 70 percent. In the second simulation, dubbed ‘severe conditions’, they set the air temperature to 32oC (89.6oF) with a humidity level of 90 percent—which happens to be the average weather conditions this week in Tokyo. As the Olympics games are being held inside a stadium, the wind speed was left negligible.
Cradle Computational Fluid Dynamics (CFD) software was used for the simulation. It is a tool used for visualizing and analyzing how fluids and gases flow. CFD has numerous predictive and modeling applications, which is why it is frequently used in aerospace, automotive, electronics and even architecture. For the Tokyo 2020 Olympics, the simulation included conditions such as temperature, humidity, the heat generated by the athlete for 30 minutes and the airflow created by their movements.
Furthermore, the runner’s body was analyzed using the JOS-2 Joint System Thermoregulation Model (JOS Model) developed by Waseda University in Japan. The model segregates the body into 17 sections and uses algorithms to make simulation/analysis adjustments based on the athlete’s size, weight, age and sex. Combining data from Cradle CFD and JOS Model, Hexagon engineers were able to scrutinize the runner’s skin temperature, core temperature, degree of perspiration, as well as the circulatory system’s performance relative to their physical and biological characteristics.
Simulation Results
Comparing the results of both simulations side-by-side revealed an alarming picture. An athlete running a 10,000 m race in average conditions experienced a core temperature of 39°C (102.2°F) and an extremities temperature of 37°C (98.6°F). While these temperatures still pose a health risk, they are considerably less concerning than the core temperature of 39.7°C (103.46°F) that the runner experienced in severe conditions. More distressing, however, was the fact that the athlete’s head temperature approached 39.2°C (102.56°F)—spiking the risk and intensity of heat strokes and even seizures.
The rate at which the athlete sweats in both conditions is also different. In severe conditions where the humidity level was set at 90 percent, the runner can sweat as much as 810ml (27 ounces) in 30 minutes—that’s more than a standard bottle of wine! At such rates, the runner is losing moisture from their body faster than the body can replenish, which can lead to painful cramps, nausea, severe dehydration, dizziness, confusion and fainting.
Given the above, the onus is on the Olympic officials and governing bodies to take the necessary precautions to ensure that these athletes remain healthy and aren’t facing unnecessary obstacles on their path to success. In fact, this wouldn’t be the first time that the Tokyo Olympics would have to make adjustments for the sake of the participants’ well-being. In the Tokyo 1964 Olympics, similar concerns were raised about temperatures, prompting officials to move the games to October 1964. Unfortunately, given that the games are already taking place, this solution is untenable. Instead, a practical recourse would be to move the more strenuous events to enclosed spaces, using air conditioning where applicable, avoiding exposure to the sun, and ensuring that participants remain well-hydrated at all times.
The Men’s 10,000 m results are in and two athletes didn’t finish the race, including Uganda’s Stephen Kissa who was an early pacemaker that dropped out at just over halfway.
According to Reuters, he said: “We had a plan for me to go ahead to make it a fast race, I thought they were going to follow me but when I looked around they were not there.”
The gold medal went to Selemon Barega of Ethiopia, and the silver and bronze to Uganda’s Joshua Cheptegei and Jacob Kiplimo, respectively. The Women’s 10,000 m will be held on Saturday, August 7th.
