Organizers of next year's Rio Olympics on Wednesday unveiled the full program of test events in the lead-up to the first ever Games in South America.
Between July and May of next year, 7,800 athletes will participate in 34 Olympic, four Paralympic and four mixed test events with more than 16000 volunteers also involved in the operation.
With next Tuesday marking 500 days to go before the start of the extravaganza, organizers said the milestone would be marked with some "surprises".
Agberto Guimaraes, executive director of sport and paralympic integration, said organizers had sought to devise a calendar of tests best served to athletes' preparation needs.
"I have no doubt we shall learn many important lessons from the test events, which we shall use to ensure we deliver the highest level of service possible come the Games," said Guimaraes.
Following on from last August's opening test for sailing, volleyball will open the next test phase with Rio hosting the World League from July 14-19.
Triathlon and paratriathlon events will follow before Rio welcomes the junior world rowing championships from August 5-9 ahead of an international sailing regatta from August 15-22.
The water-based events have generated controversy given the level of pollution in Guanabara Bay, which will host sailing and windsurfing, as local authorities strive to clean up a picturesque vista spoilt by detritus and raw sewage.
Rio originally pledged to treat 80 percent of the raw sewage in the bay despite warnings from Rio state's new Environment Secretary, Andre Correa, that the city authorities could not guarantee to meet the official target.
In December, scientists from the Oswaldo Cruz Foundation research institute said they had discovered antibiotic-resistant super-bacteria thought to emanate from hospital waste in the area while other detritus includes dead animals, television sets, sofas and shoes.
Last year, biologist Mario Moscatelli said Rio's bay was in no condition to receive the Olympics.
Brazil recently teamed with a Dutch Research Institute, Deltares, to speed the clean-up but the operation has been hampered by a lack of eco-boats, though Games sources say the boats in themselves are not an efficient solution to the problem.
The Dutch-Brazilian operation has been working since December on mapping and simulating the worst areas of accumulated pollution to increase cost-effectiveness by tackling specific areas of the Bay.
Organizers stressed the key aim is to have the Games leave Rio with a permanent sporting and infrastructural legacy.
After FIFA this week gave the green light to Manaus as a sixth host city for the football, organizers added there is "no plan B" regarding a possible withdrawal by Sao Paulo.
Corinthians club, owners of the city's Corinthians Arena, say they are  holding out for some $25 million of local authority funding for Games-related modifications to the venue.
Corinthians did not immediately respond to an AFP request on the club's stance ahead of talks with Games officials earmarked for next week.
Source: AFP