According to Official Guinness Records,
The fastest marathon dribbling two basketballs is 3 hr 54 min 16 sec, achieved by Marti Medar (Estonia) at the Tallinn Marathon in Tallinn, Estonia, on 10 September 2017.Marti Medar has also previously held the record for 'Fastest marathon dribbling a basketball.'
For a complete list of 2017 records, please visit 2017 Guinness Records in Estonia.