“March, march, march, march!”

On a hot August night in Falmouth, fitness coach Anne Curi Preisig leads a group of women through a workout in her backyard.

Even after 7 p.m., it’s still 80 degrees Fahrenheit.

"But I'm sure the ‘feels like’ temperature is above 80," Curi Preisig said. "So what I have runners do on days like today is mix in running and walking."

The group is here to train for the Falmouth Road Race, which takes place Sunday. The 47-year-old tradition brings 12,800 runners — young, old, amateur, and elite — to run the 7.3-mile race from Woods Hole to Falmouth Heights.

But over those 47 years, temperatures and humidity have risen, which has some wondering how this Cape institution will keep pace against climate change.

For runners, Curi Preisig says, an essential part of training is learning how to manage the heat.

“It's seven miles of pleasure… you tell yourself when you're done,” said Wendy Lathrup, one of the trainees, between pants.

Rising Heat By The Numbers

Cape Cod meteorologist Phil Burt has studied temperature averages for every August since 1972, when the race started.

“In the '70s and especially through the mid '80s, there were a lot of stretches there where it was pretty common where you'd have an overnight low in the upper 50s. That basically doesn't happen anymore,” Burt said.

Looking at the overnight temperature provides a solid estimate for how humid the air is, according to Burt. Wamer air holds more moisture.

Overall, since the race started, that average temperature has risen by about 3 degrees Fahrenheit.

For runners who are aiming for peak performance, a couple of degrees and the extra humidity that goes with it can have a real impact.

“If you if you go for an 8 a.m. run in the morning now, versus an 8 a.m. run 30 years ago, it's likely that it's a more uncomfortable run now than it was then,” he said.

Health Consequences of Rising Heat

That combination of greater humidity and heat makes it increasingly difficult for the body to cool itself.

“The Falmouth Road Race tends to produce a much higher rate of exertional heat stroke among its runners compared to other races,” said Julie Nolan, an exercise scientist and assistant professor of athletic training at Sacred Heart University in Connecticut.

Nolan co-authored a paper that specifically looked at the effects of heat on Falmouth Road Race runners.

For example, she and her team documented how, in 2003, the temperature was 81 degrees Fahrenheit and the humidity was 87 percent on race day. That year, seven out of every thousand runners were treated for heat stroke.

While that was a particularly hot year, Cape residents and runners should expect the trend to continue.

Nolan says part of the reason this race is so challenging to runners has to do with when it takes place.

“It's always held in the middle of August,” she said. “So the environment is kind of working against them.”

Some time in the next 47 years, might the race date be moved into September?

In a statement, race officials said anything needed to ensure runners’ safety is “always on the table."

And if it keeps getting hotter, how long will recreational runners like Wendy Lathrup continue to toe the line at Falmouth?

“Probably as long as I can keep moving,” she said. “It's just fun.”

For the many runners who will be lining up this weekend, that’s what it’s all about.

Tips on staying safe while running in the heat can be found here.