More than half said they would take the lift rather than climb two flights of stairs to their workplace, while three quarters had too little energy for sex at the end of a long day.
An entire generation risks being blighted by idleness, warned Nuffield Health, a non-profit organisation which commissioned the poll.
"Ready-meals, remote controls and even Internet shopping are all contributing to a dangerously lazy and idle Britain," said Doctor Sarah Dauncey, its medical director.
"The nation has fallen into a vicious circle of laziness that we must put a stop to," she added.
And she warned: "If we don't start to take control of this problem, a whole generation will become too unfit to perform even the most rudimentary of tasks."
In the poll of more than 2,000 adults, 15 percent said that, if the television remote was broken, they would rather continue watching the same channel than getting up and switching to another programme.
Thirty-six percent said they would not run to catch a bus, 59 percent took the lift instead of walking up even two flights of stairs, and 52 percent of dog owners said they could not be bothered to walk their pet.
Some 73 percent had no energy for sex, while 64 percent of parents were too tired to play with their children -- fuelling concern over child obesity, which already afflicts one in six pre-school infants.
"People need to get fitter, not just for their own sake, but for the sake of their families, friends and evidently their pets too," said Dauncey.