The MR8K race is an annual 5-mile course (8K) that will take place at Warrior Ice Arena at Boston Landing, the practice facility of the Boston Bruins on Monday, September 2.  Registration is $45, with proceeds benefiting the Martin Richard Foundation. Each registrant will receive a race t-shirt (first 1,500 registrants), finisher's medal, and beer ticket as part of the registration fee. The event is open to both runners, walkers, and para-athletes of all abilities, as well as families with…