Unrelenting high-tempo music, a tinny public address tannoy, strumming cicadas and the odd cry of encouragement from a small group of coaches combined with screamed commentary from excitable Japanese pundits at an otherwise empty Olympic Stadium. There was not much else audible given there were no spectators at the 68,000-capacity venue because of Covid-19 restrictions in the Japanese capital. The sole applause athletes received was from the army of local volunteers as they exited the track, masked and with hands washed. American Athing Mu, a medal hope in the 800m, played down the lack of fans."I've never been to an Olympics so I don't know how the stadium would be if it was packed with people," she said. "But then again I've run a couple of meets in the collegiate season where we didn't have spectators allowed so it was kind of the same." And Australian high jumper Brandon Starc said he was unconcerned by the empty rows in the cavernous stadium. "I don't really worry about it," said the Commonwealth champion. "I can't do anything about it, so why focus on that?" But Qatar's 400m hurdler Abderrahman Samba said it was "really, really difficult. I really missed the crowd".  - No banana skins -                         The absence of spectators, however, did not deflect from a roll-out of a number of top stars on the first day of 10 of a highly-anticipated track and field programme at the Games. At 34, Fraser-Pryce is aiming to become the first woman to win a single individual Olympic athletics event three times, to add to the 100m victories she claimed in 2008 and 2012. There were no banana skins in wait in the first round of the 100m, the Jamaican timing 10.84 seconds for the win, a way off her season best of 10.63sec, the second fastest time ever run over the blue riband event.Her compatriot Elaine Thompson-Herah is the defending champion in both the 100 and 200m, and duly sailed through her heat in trackside temperatures of 34 degrees celsus (93 Fahrenheit) with humidity at 80 percent. It was a similar tale for Britain's Dina Asher-Smith, world 200m champion and silver medallist in the 100m in Doha in 2019, and Ivory Coast's Marie-Josee Ta Lou, the latter in an African record of 10.78sec.The semi-finals and final of the women's 100m are scheduled for Saturday's evening session.- Hurdles favourites ease through -                                    One of the headline events of the Olympic track events is the men's 400m hurdles, trumpeted as a battle royale between two-time world champion Karsten Warholm of Norway and American rival Rai Benjamin.Warholm, who this month ran 46.70sec to break Kevin Young's world record set at the 1992 Barcelona Olympics, eased up to come through his heat as a winner in 48.65sec. Benjamin, world silver medallist behind Warholm at the 2019 world championships in Doha, followed suitAlso qualifying with no problem were podium contenders Alison Dos Santos of Brazil and Qatar's sub-47sec performer Samba. "It was nice to get out on the track again," said Warholm. "It's something you've been looking forward to for a long time. "I've been here for two weeks already, I'm starting to get bored so it was very nice to get around."American Juvaughn Harrison got his bid to become the first athlete to win medals in the men's high jump and long jump at the same Games since 1912 off to a good start by advancing from the qualification round in the former. "It hasn't been done in a while and I'm pleased to be the next person to do it," he said.Friday's late session features the first athletics gold medal of the Games with the men's 10,000m final, with Ugandan Joshua Cheptegei looking to better his sixth-placed finish in Rio in 2016