The former defenseman will be running in support of the Thomas E. Smith Foundation and The Hoyt Foundation.
Dick Hoyt became a well-known Boston Marathon runner after pushing his son in a wheelchair along the 26.2-mile course dozens of times. Hoyt died in September 2021 at the age of 80.
"Dick and Rick Hoyt made an incredible impact on millions of people worldwide and personally helped to motivate us to our 2011 Stanley Cup Championship," Chara said in the post. "The Hoyt Foundation has an amazing legacy with … this iconic marathon."
The Thomas E. Smith Foundation has a mission to "better the lives of those affected by and living with paralysis through financial and emotional support, as well as supporting preventive innovations that decrease the risk of spinal cord injuries," according to the organization's website.
Chara posted a donation link to his Instagram account to help raise funds for the organizations.