multiple lookups - data consolidation

i am trying to organize information about the training sessions of athletes, i have a lookup field connecting a certain days workout to a certain athlete, but sometimes athletes work together - how can i link the days workout to both athletes and still be able to get streamlined search / graph results?

i have tried multiple lookup fields (athlete 1 / athlete 2 / athlete 3 ) but sometimes "john" works out alone, or may be logged as athlete 2 or athlete 3 on other days workouts, i would like to be able to display a calender of johns workouts regardless of which athlete field he made it in...