Jimmie Johnson, one of the most fit athletes in the NASCAR Cup garage, isn’t sure how much he will learn from the biometric device that logs his heart rate during a race.

He hopes the fans and general public learn more than him.

“I’m averaging a 130-135 heart rate through a four-hour period of time, and anybody that goes out for a run and tries to carry that heart rate for four hours, they are going to be on the side of the road pretty quick,” Johnson said.

“It helps us tell the story that we are athletes inside these cars more than I can look at another driver’s limited biometrics and say, ‘They had a more difficult time than I did,’ or learn anything from it.”

Participation is mixed in the garage on use of the heart monitors, first officially legal this year, a rule NASCAR made after a discussion with the drivers council. Some drivers wear them, others scoff at the idea.

Just ask Clint Bowyer if he is wearing one.

“Hell no,” Bowyer said. “Why? The last time I checked, nobody has ever paid me to wear a heart monitor or to do anything other than finish these races up front and hopefully win them.

“I am sure mine is probably high and low. It just depends. I can tell you this, anybody’s heart monitor in this car, if something bad happens or they get cut off or crash, that will probably be the peak moment — not driving in the corner. We have power steering.”

For all the laughing that could come at Bowyer’s comment, there is an element of truth.

“I learned that I’m going crazy inside the car like you think I was,” said Penske driver Joey Logano. “My heart rate is working in there. My heart rate doesn’t slow down. I’m antsy in general. I’m too wired.

“It’s cool to see your heart rate, in particular restarts, and then on the long run it comes down a bit. The elevation is usually 10 beats at the end of the race. My peak heart rate is at the end of the race, consistently.”

Logano said his monitor did not record his postrace throwdown with Kyle Busch at Las Vegas. But he has seen something he didn’t expect.

“What was interesting is that Daytona is just as high as Phoenix,” Logano said. “Physically you’re working a lot harder at a track like Phoenix. I guess the intensity you need to have raises your heart rate a lot.”

Kurt Busch said he wore one during his Indianapolis 500-Coke 600 double in 2014. He said that the data showed his heart rate would go up right at the point he took the green on restarts and then taper back down to 110.

Busch said the information was “cute” to look at, but it’s how a driver can control his heart rate that is key.

“The biggest thing is being relaxed and being mentally focused in the car and if you can get your heart rate down,” said Busch, who can get riled up in the car. “Those devices help you track that, but it’s still the other preparations of working out and doing breathing exercises and mentally focus on how to keep yourself calm.”

NASCAR has approved 11 different devices drivers can wear. Information can’t be downloaded during qualifying nor the race. They cannot hook into the electronic system of the car in any way and no external data loggers are permitted.

Still, there is a concern about whether the GPS systems in such devices could help teams gather data about the track during the race.

If there are benefits to gather data with the devices, the benefits apparently aren’t enough to get all drivers to use them. Chase Elliott doesn’t use it often because he doesn’t like having something on his wrist when he races. Kyle Larson admitted that he doesn’t want to drain the battery in his watch, so he’ll wear it for qualifying to see how as soon as he rolls off pit road, his heart rate spikes.

“I don’t know why everybody is doing it,” Elliott said. “I haven’t worn mine in the car very much. You all know when you’re trying hard and when you’re not trying hard.

“But I’ve certainly worn it away from racing and riding mountain bikes and things like that. You kind of learn where your heart rate likes to be and when you’re trying hard, what it is and what it’s not.”

AJ Allmendinger also hasn’t used one.

“That is too much technology for me,” he said. “I know when it’s hot in the race car. I can tell you that. I can tell you my body is real hot. At Phoenix, it was really hot.”

But Trevor Bayne, who has been working with a trainer heavily involved in motocross, feels the information is beneficial. He has worn the heart monitor occasionally and uses it to see his fitness level.

Johnson said the information gathered is “very limiting” because it doesn’t show recovery time. Without knowing what other drivers’ resting heart rate is, he can’t get a good feel of how he compares through the heart monitor information.

“We all have different max heart rates and that doesn’t give you any indication of their fitness level — we just all have a different heart-rate zone that we work in,” Johnson said. “I see some people have a much higher heart rate than myself; mine is lower, that is just the way I am.

“Your fitness level is more representative by how quickly you recover and how low your resting heart rate is. It’s very difficult to see on there where that is.”

As Brad Keselowski said, he hasn’t learned all that much “to write home about.”

“I can’t train as near as high as I can race, so I don’t know what the hell that means,” Keselowski said. “I can race at 150, 160 and feel like when I go to train, when I hit 120, I’m dead. I don’t know what that means.”

But just like Johnson said, Keselowski feels the data could be worthwhile.

“Being a race-car driver is probably one of the most underestimated of athletic professions, and it’s good to have information like that to share with everybody to spread the word of what we are and what we do,” Keselowski said.