Because it happens just once a year, Thanksgiving is a great excuse to over-indulge. There's a lot of food served as it is. When people start catching up with each other's lives, it's hard to keep track of what's being consumed, resulting in intakes of between 2,000 and 4,500 calories in a single meal.

According to the Calorie Control Council, the average American eats 3,000 calories for a Thanksgiving meal, with an additional 1,500 more courtesy of snacks and drinks. That's a total of 4,500 calories, around 45 percent of which comes straight from fat. In fact, the Calorie Control Council says that the average person can easily consume fat equivalent to three sticks of butter in a holiday meal.

That's a lot, but some believe 4,500 calories is, while possible, an overestimation.

Tara Parker-Pope from the New York Times, for example, contested this number in 2012 by serving up the most calorie-dense Thanksgiving dinner she could, but only came up to 2,486 calories. Cedric Bryant from the American Council on Exercise also did his own calculations and determined that 3,000 calories is more right on target.

The basics of a Thanksgiving meal aren't all that terrible actually, it is the second helpings and embellishments that send calories skyrocketing. Who could ignore such a glorious spread, after all?

So, what would it take to burn off 3,000 calories?

Just how much exercise you have to do will depend on your weight as well, but a 160-pound individual should expect to walk 30 miles, swim for five hours, or run for four hours at a moderate pace to trim all of those calories away.

Also, before you reach for that piece of pecan pie, consider this: a slice has 503 calories, which will require a 45-minute workout consisting of burpees, air squats, and lunges. Is it worth it?

Thanksgiving only lasts a day and overeating on the occasion is probably not going to have long-term ill effects, but the trouble is that it's the first of many holiday binges lined up until the end of the year. After all that holiday cheer, it's not unusual to gain two or three pounds, extra poundage that won't budge once January rolls in.

That is unless people squeeze in some exercise in between the festivities. Got a big dinner coming up? Run in the morning! Even walking after dinner will help.