RIO DE JANEIRO (AP) -- Rio Olympic organisers are taking advantage of Brazil's huge Carnival celebrations to deliver its first sports venue for the 2016 Games -- the Sambadrome. The city's highly popular Carnival parades this weekend will serve as a test run for the renovated venue, which will host the archery competitions and will mark the marathon's start and finish. The Sambadrome was upgraded throughout its half-mile-long (0.8 kilometer) stretch where samba schools parade their scantily clad women and colourful floats, but the biggest change was the addition of four new grandstands, increasing its capacity from 60,000 to 72,500. Renovation The $20 million renovation leaves the Sambadrome ready for the Olympic competitions four years ahead of the Games. The venue was officially reopened on Sunday, when about 1,000 athletes and Carnival revelers participated in a 5.5-kilometer (3.4-mile) race. "The opening of the Sambodromo is a testament to how the Games are integrated with the city," Rio 2016 Olympic committee president Carlos Nuzman said. "The choice of this venue for the archery and the marathon events not only gives us the opportunity to stage competitions against a worldwide known setting, but also offers Rio de Janeiro a renovated, enlarged stage for one of the city's largest popular celebrations." The renovation concludes the original project created by architect Oscar Niemeyer in the 1980s. Former marathon runner Vanderlei Cordeiro de Lima, bronze medalist at the Athens Games in 2004, approved the Sambadrome as the marathon venue in 2016. "These grandstands will certainly be filled for the marathon finish, which will further motivate and encourage the athletes, making this moment even more special," he said in a statement. Lima was the runner attacked by a protester while leading the marathon in the Athens Games. In addition to the new grandstands, the new Sambadrome also was adapted to offer better access to people with disabilities, received new hospitality boxes and gained new sound systems in its renovation which began in 2011.