Pope Benedict was wheeled into mass on Sunday to spare him from fatigue from walking.
The 84-year-old pontiff used a wheel platform to get up the long aisle of St. Peter's for the first time. The device was built to transport the late Pope John Paul II during the final five years of his life.
As the platform was pushed up the aisle by aids, Benedict held on to his pastoral staff with one hand and the device's support bar with the other.
Chief Vatican spokesman Father Federico Lombardi said there is nothing to worry about regarding the Pope's health.
"This is just not to tire him," Father Lombardi said. "Nothing else should be read into the general state of his health, which is good."
"The sole purpose is to ease the effort of the Holy Father, to reduce the fatigue," Lombardi told journalists.
Vatican sources did say that the Pope suffers from high blood pressure
Benedict walked around the central altar as well as up and down its steps, but appeared less energetic than usual, AP has reported.
Benedict was elected in 2005 after Pope John Paul's death and has had a far more relaxed schedule than his predecessor.
Aides say that because Benedict was 78 when he was elected, he decided to be cautious and limit his activities. Pope John Paul was 58 when he was elected.
During the mass on Sunday, the Pope announced that he was calling a "Year of Faith" for all Roman Catholics and will start on October 11, 2012, the 50th anniversary of the start of the Second Vatican Council. The council brought modernizing reforms, efforts to strengthen relationships with other faiths and celebrations of mass in local languages of Catholics worldwide rather than Latin.
The year will present the opportunity for Catholics to "reinforce our faith" in God and "to announce him with joy to mankind," Benedict said.