Wearable fitness devices have moved into the mainstream helping people pick up the pace of their daily activities.

The devices are flooding the marketplace as the technology and sports industries create “wearable fitness coaches” for customers interested in tracking their activity levels, food intake, heart rates and sleep patterns.

Most of the new devices are designed to be worn on the wrist, although a few models can be carried in a pocket or clipped onto clothing. Nearly all track the number of steps taken and time of activity. Some models go beyond and monitor sleep, heart rates or even perspiration.

Data from the wristband or clip-on device is synced to a computer or mobile phone to give users charts and graphs of their progress. They can use the data to chart their performance over time or see how they stack up with others. Devices sync with their own applications — or to outside apps like MapMyFitness, Runkeeper or MyFitnessPal.

Prices vary — from $50 to more than $200 — based on the amount of data tracked and additional functions.  Manufacturers include Basis, Fitbit, Jawbone, LG, Misfit, Samsung and TomTom. Some models are designed for cycling or swimming, or import smart phones functions like social media or texting.

Although fitness enthusiasts were among the first to wear trackers, online nutrition and weight loss communities are becoming interested in them too, according to Angela McIntyre, a research director covering wearable computing for Gartner, Inc.

Calorie tracking and counts, along with food diaries, can help users monitor their diet. Some commercial weight loss companies are now selling fitness bands as add-ons to help their customers stay active and lose weight.

As Americans overall have become increasingly sedentary — expending less calories and being less active,  leading to weight gain — over the years, many people are turning to activity tracking versions to help them pick up the pace of their daily activities.

“Yes, they are here to stay,” McIntyre said, adding that the quality of the wristbands and data they provide are good enough to help people become more fit.

About 3.3 million activity trackers were sold between April 2013 and March 2014, according to the NPD Group. Sales are projected to reach more than $1 billion in 2014.

The devices won’t jump-start the activity levels of fitness enthusiasts, who have been the first to embrace the activity tracker, said Kevin Tillmann, senior research analyst for the Consumer Electronic Association. Instead, they help them reach their fitness goals.

People with specific athletic training goals may prefer a sports watch or GPS-enabled device, because they can be paired with a heart rate monitor chest strap that provides more accurate information, McIntyre said.

However, using an activity tracker can motivate people who aren’t already active.

“What’s great about this is that there are so many of us who don’t have time to exercise.  I don’t have time to sleep,” McIntyre says. “If I have one of these devices that’s helping me track the exercise I do in a day, maybe I can find small little ways to get more exercise in my life.  I believe this is an important way that these can help regular people who aren’t so much into fitness.”

Former American Heart Association president Donna Arnett, Ph.D., has worn her activity tracker since January 2013 and said she’s never without it unless it’s charging.

“It keeps me walking — I have a set of friends that I compete with and I try very hard to stay on top,” said Arnett, also professor and chair of the Department of Epidemiology at the University of Alabama at Birmingham’s School of Public Health. Her goals are to walk 15,000 steps a day and get at least 6 hours of sleep every night.

Most current users wear their trackers every day, finding they help them stay motivated, monitor progress towards fitness goals, and track the amount and intensity of physical activity, according to a CEA survey.