Tokyo is hoping to turn the spotlight from the radioactive water leak at the crippled Fukushima nuclear plant in northern Japan, while Madrid is looking to fend off concerns related to Spain's high unemployment rate and economic struggles.
The host city will be selected Saturday by the IOC, joined by the third candidate Istanbul. The Turkish city also faces questions about a string of embarrassing doping cases and a civil war in Syria on its border.
Tokyo is considered as the favorite, although the race is viewed as too close to call as IOC members may settle for the bid with the fewest problems.
Yuki Ota, a two-time silver medalist in fencing, was one of a dozen athletes who appeared at a news conference to promote Tokyo's bid.
"I'm proud that no Japanese athlete has ever failed a doping test in the Olympics or Paralympic Games," Ota said. "I do not believe that education about doping can be achieved by one law alone. Long ago, Japan took action."
Ota was making a veiled reference to a recent anti-doping law passed in Spain.
Madrid has tried to deflect inquires about the 27-percent unemployment rate in one of Europe's largest economies, and Gasol was quick to say the city's bid is "very strong" and poses "no risks.
"We are promoting sports here," he said. "But hosting the Olympic Games at home would also be a big boost for our society. It would bring contributions to all sectors, it would help everyone grow."
Gasol, a two-time Olympic medalist, was also on the bid team in Singapore in 2005, when Madrid lost the 2012 bid to London. It lost the 2016 bid to Rio de Janeiro.
"I think we have grown from the time we lost in Singapore and maybe that will be decisive this time," he said.
Istanbul bid leader Hasan Arat shunned celebrities and introduced 20 young people as the face of Turkey. He said half of Turkey's population was under 25, and added that half of Istanbul's delegation at Saturday's final presentation to the IOC would also be under 25.
Arat sought questions from reporters, and the first dealt with recent street protests in Turkey. He asked high school student Esen Kucuktutunca to reply.
"That's kind of a normal thing," she said. "It's a democracy. People have the right to protest. It happened in London and lots of countries."
The students were asked about press freedom in Turkey, and Arat responded to the question.
"I'm not a politician, I'm a bid leader," he said.
AP Sports Writer Tales Azzoni contributed to this report.
Follow Stephen Wade at http://twitter.com/StephenWadeAP
Follow Tales Azzoni at http://twitter.com/tazzoni