Fitbits, other fitness wearables, hit the pavement for annual Cooper River Bridge Run

MOUNT PLEASANT, S.C. (WCIV) -- When Sarah Martin sets out for her fourth Cooper River Bridge Run Saturday, she'll be dressed in her usual uniform: a slapstick running T-shirt, shorts, sneakers and her Fitbit bracelet. The device fits snug around the wrist and tracks steps, pace and heart rate.

"It's a really good pacesetter for people who are runners," Martin said.

Fitbit is one of several wearable fitness products on the market to help people who practice all levels of exercise. The bracelet wearables, along with competitors like Jawbone and a discontinued product from Nike, track exercise and sleep statistics throughout the day. For example, they can tell you heart rate, how many steps you take and when you are at rest.

They range in price from about $100 for the most basic models, to about $250 for the most sophisticated.

The market for fitness wearables started booming about six months ago, according to Jonathan Beverly, editor-in-chief of Running Times.

"For runners, it's almost ubiquitous to have a heart rate monitor," Beverly said.

Beverly said the devices revolutionized the way runners acquire that vital statistic.

According to fitness insiders, Fitbit accounted for 67 percent of all fitness tracking devices in 2013. Some market experts predict Apple's new watch will be the products' downfall; Apple will release the new technology for purchase next month.

But, Martin said she'd stick with her Fitbit band to stay motivated in her running and in everyday life.

"It's one of those slaps in the face of knowing, 'I'm a bum today. I need to do a walk or run.' You're more aware that you have not worked out that day or haven't done as much physical exercise as you need to do. Everyone has a goal. It keeps you motivated to get to that goal," she said.

The device has also changed the way Martin approaches races like the Cooper River Bridge Run. She has done the 10K race for the last three years and also completed three other races in the last month.

"Especially going over the bridge, when you're in the elevation in the climb, I'll definitely be looking at it to see my pace and keep me on track," she said. "We have our goal time. You have to keep checking in on it."

Beverly echoed Martin's sentiment. He said wearable fitness bracelets help runners stay in check with their health and progress.

"Pace is the outcome, but heart rate is what you are putting in to it. You can monitor how hard you're working. Elite runners do 80 percent of their work below the aerobic threshold. Your heart rate can tell you whether you're there," Beverly said.

As Martin prepared to make the trip to Charleston from her home in Columbia, she packed her Fitbit, knowing it would keep her on pace to finish the landmark run a fourth time.

ABC News 4 attempted to reach Fitbit for comment on this story but the company did not respond to repeated requests.