Just as many will most likely break that promise.
Millions of Americans are hitting the gym this week, and people here in the Valley are no different.
Local gyms say hundreds of people sign up for memberships this time each year.
"We get really busy. Right before New Year's comes and then January, February, March a lot of people just flood in. Real excited about the New Year's resolution. We give them free personal training sessions to try and get them going too as well. Because they need support and what to do when they're out there," Fitness 19 manager Theresa Cappelletty said.
Fitness 19 in Northwest Fresno offers monthly dues of as little as $9.
People are taking advantage of its 12-day free trial, appropriately picked for this year.
The affordability leaves people like Tamboura Nettingham more likely to go through with their New Year's resolutions.
"My New Year's resolution is to get in shape, shed some pounds and just have a happier life," Nettingham said.
Weight loss is the number one resolution make every single year, but it's also the toughest thing to keep. That's why a lot of people will be turning to their smartphones to stay on top of things.
What if you had a reminder in your pocket every day?
That's the goal of smartphone apps like Resolutions 2012, which lets users choose goals, identify habits they need to change to meet them, and track progress.
One called Gympact even goes as far as making people pay if they don't promise to workout as many times as they promise.
But achieve what you set out for and they will pay you the money you put up.
Action News AM Live fitness expert Rhonda Murphy says these apps will help, but success still means taking it slow.
"Start off small. What happens if you start achieving these goals small then you're going to feel a lot better. If you start going to far and run a marathon and you've never even walked a mile, how are expecting to do that. So take baby steps," Murphy said.
Taking those baby steps now can lead to bigger weight loss gains down the road.