Way of the warrior kid : from wimpy to warrior the Navy SEAL way
(Book)

Series information from publisher website.

Fifth grade was the worst year of Marc's life. He stunk at gym class, math was too hard for him, the school lunch was horrible, and his class field trip was ruined because he couldn't swim. And the most awful thing about fifth grade? Kenny Williamson, the class bully, who calls himself the King of the Jungle Gym. When Marc's mother tells him that his uncle Jake is coming to stay for the whole summer, Marc can't wait. Uncle Jake is a for-real, super-cool Navy SEAL. And Uncle Jake has a plan. He's going to turn Marc into a warrior. Becoming a warrior isn't easy. It involves a lot of pull-ups, sit-ups, push-ups, squats, swimming, eating right, and studying harder than ever before! Can Marc transform himself into a warrior before school starts in the fall-and finally stand up to the King of the Jungle Gym? -- from Amazon.