7-time NASCAR champ Johnson to run Boston Marathon
In this Jan. 31, 2019, photo provided by Jimmie Johnson Racing, NASCAR driver Jimmie Johnson runs in Las Vegas. The 83-time winner on the racetrack (sixth-most all-time), Johnson has long been a fitness freak who swam in high school and has run half marathons and triathlons. Johnson plans to run in the Boston Marathon on Monday, April 15, 2019. (Adam Moran/Jimmie Johnson Racing via AP)

In this Jan. 31, 2019, photo provided by Jimmie Johnson Racing, NASCAR driver Jimmie Johnson runs in Las Vegas. The 83-time winner on the racetrack (sixth-most all-time), Johnson has long been a fitness freak who swam in high school and has run half marathons and triathlons. Johnson plans to run in the Boston Marathon on Monday, April 15, 2019. (Adam Moran/Jimmie Johnson Racing via AP)

Apr. 14, 2019 06:07 PM EDT
FILE - In this April 19, 2015 file photo, NASCAR driver Jimmie Johnson runs through the tunnel during a rain delay in a Sprint Cup Series auto race at Bristol Motor Speedway in Bristol, Tenn. Johnson plans to run in the Boston Marathon on Monday, April 15, 2019. (AP Photo/Wade Payne, File)

FILE - In this April 19, 2015 file photo, NASCAR driver Jimmie Johnson runs through the tunnel during a rain delay in a Sprint Cup Series auto race at Bristol Motor Speedway in Bristol, Tenn. Johnson plans to run in the Boston Marathon on Monday, April 15, 2019. (AP Photo/Wade Payne, File)

Apr. 14, 2019 06:11 PM EDT
In this April 6, 2018, photo provided by Jimmie Johnson Racing, NASCAR driver Jimmie Johnson runs in Avondale, Ariz. The 83-time winner on the racetrack (sixth-most all-time), Johnson has long been a fitness freak who swam in high school and has run half marathons and triathlons. Johnson plans to run in the Boston Marathon on Monday, April 15. (Bryan Knox/Jimmie Johnson Racing via AP)

In this April 6, 2018, photo provided by Jimmie Johnson Racing, NASCAR driver Jimmie Johnson runs in Avondale, Ariz. The 83-time winner on the racetrack (sixth-most all-time), Johnson has long been a fitness freak who swam in high school and has run half marathons and triathlons. Johnson plans to run in the Boston Marathon on Monday, April 15. (Bryan Knox/Jimmie Johnson Racing via AP)

Apr. 14, 2019 06:10 PM EDT
In this Jan. 31, 2019, photo provided by Jimmie Johnson Racing, NASCAR driver Jimmie Johnson runs in Las Vegas. The 83-time winner on the racetrack (sixth-most all-time), Johnson has long been a fitness freak who swam in high school and has run half marathons and triathlons. Johnson plans to run in the Boston Marathon on Monday, April 15. (Adam Moran/Jimmie Johnson Racing via AP)

In this Jan. 31, 2019, photo provided by Jimmie Johnson Racing, NASCAR driver Jimmie Johnson runs in Las Vegas. The 83-time winner on the racetrack (sixth-most all-time), Johnson has long been a fitness freak who swam in high school and has run half marathons and triathlons. Johnson plans to run in the Boston Marathon on Monday, April 15. (Adam Moran/Jimmie Johnson Racing via AP)

Apr. 14, 2019 06:03 PM EDT
FILE - In this Feb. 16, 2019 file photo, Jimmie Johnson leaves his garage after NASCAR auto racing practice at Daytona International Speedway in Daytona Beach, Fla. Johnson plans to run in the Boston Marathon on Monday, April 15. (AP Photo/Terry Renna, File)

FILE - In this Feb. 16, 2019 file photo, Jimmie Johnson leaves his garage after NASCAR auto racing practice at Daytona International Speedway in Daytona Beach, Fla. Johnson plans to run in the Boston Marathon on Monday, April 15. (AP Photo/Terry Renna, File)

Apr. 14, 2019 06:13 PM EDT