HOLLIS – Colder weather and shorter days can often slow down even the most dedicated with their fitness routine.

Add the holiday season to that, and many will be wishing they had passed on the cheesecake when they try to button their “skinny jeans.”

Bodies Defined Fitness Studio owner and trainer David Holman says winter weight gain is fueled by many factors.

“Colder temperatures keep many of us indoors,” Holman said. “Less exercise means a slower metabolism. Less sunlight can make us feel depressed and cause craving for high-carb comfort foods.”

Coupled with high-calorie temptations at holiday gatherings, Holman says people quickly fall behind on their health and fitness goals.

Holman and his wife, Kim, run a fitness studio in Hollis. Both are personal trainers and say that they hope to help local residents lead a healthier life. Acknowledging the growing trend toward an overweight population, they agree it’s never too soon to start or too late to change.

Recent reports from the Centers for Disease Control and Prevention suggest the estimated prevalence of obesity among adults was 26.7 percent in 2009 and now affects 17 percent of all children and adolescents in the United States. Obesity contributes to several leading causes of death, including heart disease, stroke, diabetes and even some types of cancer.

According to the CDC, obesity also affects rising health care costs: On average, people who are obese have medical costs that are $1,429 more than people of normal weight.

To help jump-start fitness endeavors, as well as encourage long-term improvements, Bodies Defined offers a “12 Weeks to Your New Body Challenge.” This nutrition and wellness program includes personal training, group fitness classes, a nutrition seminar, supplement guidance, a healthy cooking class, a detailed workout log, fitness assessments and before-and-after measurements.

“We wanted to put together a comprehensive program where clients could see real results in a reasonable amount of time,” Kim Holman said. “Our debut groups of participants lost a combined total of 527.4 pounds and 528.3 inches.

“Now, we are running our third challenge with many of our earlier participants still committed to their healthier lifestyles. There is nothing more motivating than feeling good and looking better.”

Challenge participant Althea Proko is only halfway through the current 12-week program, and says she has already enjoyed some “big changes.”

“This program is a good incentive to improve your life,” she said.

The challenge is tailored to meet each individual’s needs and also limitations. All participants are expected to consult their doctors and monitor their physical wellness as needed to prevent injuries. Participants are weighed and measured regularly to instill some friendly competition and determine the overall “winner.”

“Although we award an overall winner to the challenge, there are no losers,” Brian Benoit said. “Anyone willing to take on the program and commit to the workouts is a winner by any standard. We help each person aspire to their personal best.”

Benoit, a certified personal trainer with more than 20 years of teaching experience, is the kickboxing and kettlebell instructor at Bodies Defined. Also a second-degree black belt in tae kwon do, Benoit designs workouts for every level that are intense, yet fun.

Sally Cadman, an advanced practice nurse and amateur horse rider, has been working out at Bodies Defined for more than a year. She said her initial goals included stress management through exercise and a stronger core to improve her abilities in the saddle as an avid equestrian.

“I have been able to work and improve even with osteoarthritis,” Cadman said. “I’m able to get the benefits of lifting weights safely.”

For those already thinking about New Year’s resolutions, the next 12-week challenge” will begin Jan. 21.