Christie said he would work out with his trainer Friday morning before heading to the Statehouse for three private meetings. The governor also was scheduled to attend a dinner Friday night, but said he would cancel his schedule if he woke up feeling unwell.
"I don't want you (the news media) or anybody in the state to be concerned about me. I'm fine, I feel fine," Christie said. Then he joked, "I think you all got the idea I was fine when (his wife) Mary Pat left, that I was fine or dead."
The governor walked out of Somerset Medical Center around 6:30 p.m. Thursday and took questions from reporters after undergoing several hours of tests at the hospital in central Jersey, including a chest x-ray, an EKG and blood work that all came out normal.
Christie, 48, uses an inhaler for asthma and is overweight. He was headed to a bill signing event Thursday morning when he felt short of breath and became light-headed, so he had his state police detail take him to the hospital. Christie has never been hospitalized in his 18 months as governor, and the last time he sought emergency treatment for asthma was more than 20 years ago when he was in law school.
The governor told reporters that his breathing problems were likely the result of humid weather and summer allergies. Christie said he would continue to watch his diet, exercise and try to lose weight, but didn't anticipate making any lifestyle changes as a result of Thursday's incident, adding that he plans to see his own asthma doctor next week as a precaution.
Mary Pat Christie went to the hospital after being told of her husband's situation, but left after a few hours to attend their son's baseball game. The Christies have four school-age children.
Christie has drawn praise from fiscal conservatives and complaints from unions for efforts to trim benefits for public employees as part of steep budget cuts. His national profile also has risen, in part, for his frank and sometimes confrontational exchanges with the media, and some Republicans have been trying to persuade to run for president.
The governor had attended an education conference and a congressional fundraiser in Iowa on Monday, where he again told reporters he was not running for president. He reiterated that position Thursday when a reporter asked him if he thought his health issues would hurt him if he sought the presidency.
Christie has been open about some of his health problems.
He has long struggled with his weight, which he said he started putting on after high school when he stopped playing organized sports. He's tried dozens of diets over the years with varying success and has shed some pounds in recent months.
DeFalco reported from Trenton, N.J. Associated Press writer Josh Lederman in Trenton contributed to this report.