The Science of Sweat

Excerpted from Dirt Sports Magazine | The Voice of Off-Road Motorsports   June 2009

By Marty Fiolka

Like most other forms of motorsports, in the past decade, the factors differentiating winning and losing in off-road racing have been substantially refined. The advent of readily available, off-the-shelf technology has narrowed the competitive gap between our sprot’s front runners and also-rans, creating a modern environment in which, like NASCAR, the difference between ultimate success and failure has been refined to very subtle degrees of separation. Let’s face it, as the best of technology becomes more readily available, so too will become the emphasis on smaller details making a bigger difference.

This modern racing paradigm was recently exemplified in a big way via our visit to safety equipment manufacturer Stand 21’s American headquarters. Hosted by none other than French company founder Yves Morizot, our trip to Stand 21’s offices yielded a wealth of significant information regarding the science behind the direct correlation between overall human body heat and a driver’s overall performance.

The simple truth is that off-road racers, whether competing in desert, short-course or rock crawling, all face an environment characterized primarily by excessive temperatures. And while we won’t hesitate to spend thousands of dollars on the latest components or technology that provides a competitive mechanilcal edge, scientific advantages that focus on enhanced human performance are pretty much overlooked entirely.

In 2003, Stand 21, with an international team of medical specialists, the health department of the French army and several major racing teams began a two year research study on body heat and racing, an undertaking that resulted in 500 pages of precise data. Thankfully condensed down to a short presentation, we looked at the surprising impact driving suits and heat stress can play on driver performance. While much of the information Morizot shared with us is very scientific and, by nature, more than a little difficult to comprehend, the gist of what he shared was also very informative.

In the very extensive (and expensive) study, Stand 21 came to understand that humans must maintain a stable body temperature in order to perform at their peak, which means maintaining a balance between heat gain and heat loss. According to the research, if the heat loss a driver experiences is smaller than the heat gain, then the driver is in a condition known as “heat stress.”

While admittedly much of this concerns the extremely high heat found in enclosed cockpit vehicles such as sports cars and even front-engine race cars like NASCAR, this information is no less concerning to the Dirt Sports Nation considering the environment (both outside ambient temperature and vehicle heat related) under which drivers and co-drivers are asked to compete.

According to the findings, when a driver’s body heat rises so will the heart rate reducing performance, impairing behavior and psychomotor skills and, more significantly, becoming a life-threatening situation as well.

What’s important here to realize is that a failure to dissipate/correct the factors that cause heat stress can raise body temperature to dangerous levels. The body will store heat, thus raising the core body temperature until it reaches syncope (see below) or exhaustion.

Amazingly, the research also discovered that a driver in good condition, with a high level of cardio vascular fitness, only had minimal impact on reducing heat stress conditions as did heavy ingestions of fluids. Even such extreme training methods as heat acclimation programs needed at least three weeks to be efficient and took only three days to lose the benefits.

According to Morizot’s report, the most significant ways to lower the risk of heat stress for drivers and co-drivers is to lower the ambient temperatures or to control the “micro environment” of the safety equipment, which means helmets, suits and underwear. Short of adding air-conditioning and closing the cockpit (which is heavy, costly and complex), the more efficient solution is taking a closer look at what the racers are wearing.

In terms of this solution, there is both good news and bad news as it relates to the off-road crowd. Thankfully, the early adaptation of fresh air helmets (actually invented years ago by desert racers) is a first big step to aiding in driver/co-driver comfort. Yes, these units do aid in providing dust-free air to increase visibility, but a far more hidden value is found in the fact that the head and neck areas are cooled by the fresh air, an important factor in maintaining a cooler overall body temperature.

Unfortunately, the benefits of upgrading to better driving suits have pretty much been overlooked by everyone, including both desert racing and short course sanctioning bodyes which still allow old-fashioned, single layer “fire” suits. While the importance of keeping costs down to sportsmen racers and enthusiasts is clear, the fact is that these lower priced alternatives are a double-edged sword. The most obvious disadvantage/danger to a driver is the decided lack of protection from fire and heat transfer when compared to a more modern two layer/underwear combination. But, now it is also understood that these suits, which have a much tighter weave in their material’s construction, also translate into them creating a “greenhouse” effect for their wearers. And, by decreasing breathability, the skin’s temperature will increase faster than a body’s core temperature.

What is the bottom line to all of this according to Stand 21? Do as much as you can to keep your body temperature down when racing, which includes lots of hydration, mounting your car’s fresh air pumper away from heat sources and invest in the best possible (and most breathable) driving suit you can. Not only will you be a more comfortable driver, but, according to this scientific study, you will be a faster one as well.

Syncope: Partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings.  When the loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope or, in nonmedical quarters, fainting. Syncope accounts for one in every 30 visits to an emergency room. It is pronounced sin-ko-pea.

Syncope is due to a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness or a “black out” episode, a loss of consciousness. Temporary impairment of the blood supply to the brain can be caused by heart conditions that do not directly involve the heart.