Recep Tayyip Erdogan addresses supporters after reports of health concerns
Thousands of people from different cities around the country convened on Ankara Millet Park.
Erdogan criticised opposition parties and main challenger Kemal Kilicdaroglu during the speech. He said they were supported by terrorist organisations like FETO and PKK.
With just under two weeks to go until the election, Erdogan's health has raised concerns after he cancelled his campaign trips for two days in a row, including a previously scheduled trip to a high-profile ceremony at Turkey's new power plant in Mersin on Thursday.
Student Emre Ali Ferli has known no leader other than Recep Tayyip Erdogan.
That's enough to make the 18-year-old back the Turkish president's rival when he votes for the first time on 14 May.
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"I am tired of getting up every day and thinking about politics," he said, referring to the tumult of Erdogan's 20-year rule.
"When President Erdogan is gone, young people will be able to focus on their exams and to speak freely."
Like Ferli, around 5.2 million Turks who reached voting age since Erdogan came to power in 2003 - eight per cent of the electorate - will have their first say on election day.
Former civil servant Kemal Kilicdaroglu, 74, is banking on students such as Ferli.
"It is through you that spring will come," the grandfatherly leader of Turkey's main secular party told a youth rally in Ankara.
Opinion polls suggest that Kilicdaroglu has reason to be optimistic.
One survey showed only 20 per cent of Turks in the 18-25 age bracket were ready to vote for Erdogan and his Islamic-rooted party in the presidential and parliamentary polls.
Both past Turkey's retirement age, Erdogan and Kilicdaroglu have been trying to seduce Gen Z voters with pledges to abolish a tax on mobile phone purchases and free internet packages.
Adding to Erdogan's problems, a third candidate, 58-year-old secular nationalist Muharrem Ince, is posing as a more fresh-faced alternative.
"The Erdogan vote is lower among young people," Konda polling institute researcher Erman Bakirci said.
"First-time voters are more modern and less religious than the average voter, and more than half are dissatisfied with the life they lead."