Which sport did John Aalberg participate in?
sport refers to sport_name;
SELECT DISTINCT T1.sport_name FROM sport AS T1 INNER JOIN event AS T2 ON T1.id = T2.sport_id INNER JOIN competitor_event AS T3 ON T2.id = T3.event_id INNER JOIN games_competitor AS T4 ON T3.competitor_id = T4.id INNER JOIN person AS T5 ON T4.person_id = T5.id WHERE T5.full_name = 'John Aalberg'