Organisers and athletes hailed Sunday's Rio 2016 Olympic marathon test event as a success despite hot autumn conditions. Rio 2016 venue management director Gustavo Nascimento said the 42 km course, which will start and finish at the 700m-long Sambadrome, could see slight alterations before the event on August 21, Xinhua news agency reported. "Maybe there will be some minor changes to the route but in general it (the test event) went very well," Nascimento said. He added that the final route would be discussed in the coming week and confirmed in July. Marcio Barreto da Silva was first to cross the finish line in a field of 16 participants, recording a time of 2 hours, 21 minutes and 22 seconds. "The route is well marked and the organization was perfect," Da Silva said. "What had the biggest impact was the heat. It was a great thrill to be part of test for an event that will feature the world's best athletes," he added.