Meaning: in sports you play with your off hand with the sport your doing football,baseball,basketball, and tennis.
Example:lebron james shoots with his right hand but he is naturally a lefty he writes with his left hand and eats with his left hand he has mixedhandedathleticism.
In sports you would use your off hand in like football,baseball,basketball, and tennis.
Example:lebron james and russell westbrook both have mixedhandedathleticism they do everything else with there left hand.