He may already be 76 years old and may technically only have one functioning lung, but Pope Francis had been up and about in Rio de Janeiro. His horde of security aides could hardly keep up as the pontiff of the Roman Catholic faith exuded the same energy level as with the youth contingent present in the World Youth Day 2013 festivities.

Pope Francis has been reported to have kept altering his schedule up to the last minute, accepting engagements, never mind if it his calendar is already full. On Thursday, he added two unscheduled events, including a morning Mass with some 300 seminarians from the region, as well as a meeting with some 30,000 Argentinean pilgrims at Rio's cathedral.

World Youth Day 2013: Younger Security Aides Hardly Coping with Energetic 76-year-old Pope Francis

Not even the rains, which forced major changes in the World Youth Day agenda, dampened the spirits of the 266th successor to St Peter's throne.

Pope Francis is scheduled to hold mass on Sunday in a rural countryside location, but the incessant rains, which have transformed the target venue into a giant pit of knee-deep mud, forced organisers to hold the Mass instead at Copacabana beach, the same site as with his Thursday gathering.

Rev Federico Lombardi, spokesman of Pope Francis, said the alert and full of vigour demeanor of the supreme pontiff is nothing new to him.

Ever since the former Argentine priest rose to the position in March 2013, he has been practically everywhere around Vatican and its halls, practically stressing everyone with his seeming hands-on style and quick-to-the-draw approach.

But Rev Lombardi immediately clarified the pope's management of his bailiwick in Rome is a "good thing."

The good-natured priest, however, did make one slip of the tongue.

"I'm happy we're half-way through (this WYD 2013) because if it were any longer I'd be destroyed."

Meanwhile, Rev Lombardi announced Pope Francis will make another international visit in 2014, eyeing either Africa, Asia or the Holy Land.