Here is an interesting article comparing the campaign energy of different candidates:

Mitt Romney
Republican Mitt Romney exhibits the energy of a hummingbird, often starting at 7 a.m. and finishing at 10 p.m. The former Massachusetts governor can pack six or seven public appearances in a day, with radio interviews and staff calls along the way...

A recent snapshot of candidate schedules shows the most consistently prolific campaigners include Romney...

"It's not unusual to find ourselves in four states in a single day, particularly in the last month of a quarter, when the emphasis is on fundraising," said Fehrnstrom [a Romney spokesman].

Fred Thompson
Republican rival Fred Thompson takes a more leisurely pace, with just two scheduled public stops in Iowa the day after he declared his candidacy on NBC's "The Tonight Show With Jay Leno."

Last week, the former Tennessee senator dropped out of public view for a day, prompting the Democratic National Committee to jab in a release, "Thompson Tuckered Out After Only a Week of Campaigning."

Rudy Giuliani
Former New York Mayor Rudy Giuliani, also seeking the GOP nomination, had a burst of public events in the days leading up to Sept. 11, the sixth anniversary of the terrorist attacks that targeted his home city and boosted his national prominence such that he is now the national front-runner for his party's nomination.

More typically, Giuliani's day will include one or two splashy public events, followed by an undisclosed number of private meetings with donors and supporters. One day in August, he flew back and forth to Saratoga, N.Y., so he could attend a fundraiser amid a New Hampshire campaign swing.

Giuliani's events frequently begin at 9 a.m., two hours after Romney is often on the trail.

What type of person do you want sitting in the Oval Office?