Harare - The Zanu-PF youth wing insists that President Robert Mugabe is "switched on" and able to lead the country to 2023, when he’ll turn 99.Youth secretary Kudzanayi Chipanga, who is organising countrywide rallies for the 93-year-old president, said the youths won't "stampede" Mugabe into naming a successor."He is still fit to execute his duties," Chipanga said in comments carried by the state-run Herald. "Mentally and physically he is switched on." 'Our president is still strong'Last week Mugabe's 52-year-old wife Grace urged her husband to name a successor, saying his word on the matter would be final and put an end to clandestine jockeying by senior party officials to succeed him.But Chipanga said though the youths agreed "100 percent" with the First Lady's call, "we are not stampeding His Excellency to choose a successor"."He can even go up to 2023," he said. "Our President is still strong as you can see him addressing his party supporters for more than an hour when the need arises."Another five yearsMugabe is limited to two terms under the new constitution. He wants to stand for re-election next year for a second five-year term.But he looks old and frail and possibly not up to leading a gruelling re-election campaign.At last weekend’s youth rally in the northern town of Chinhoyi, the president appeared to be fast asleep on the podium while his wife publicly berated his spokesperson George Charamba for allowing state media to criticise her allies in government.