Meet Sarah Johnson, fitness DVD addict. The 32-year-old Alexandria resident considers her handpicked collection of workouts her “prized possessions,” particularly the titles featuring instructor Shaun T. (“He helped me lose 30 pounds and so many inches,” she says.) Johnson loves progressing through a familiar routine. She feels like she’s become buddies with the folks on screen.

So why doesn’t Johnson have plans to buy any more DVDs — not even this month, the biggest time of year for the fitness industry? There’s simply too much competition for her muscles.

Her marketing job keeps her on the road a week each month, and her phone travels with her everywhere. Google’s fastest-growing app category in 2014 was health and fitness. So for those hotel-room workouts, Johnson now uses Sworkit (free, or $1.99 for the premium version, iOS and Android), which spits out customizable circuit-training routines.

On the side, she’s experimenting with streaming workouts, which have transformed the Internet into an all-you-can-sweat buffet. For now, Johnson has just sampled free options, including the BeFit YouTube channel and Popsugar (available on YouTube and Hulu), and she’s been consistently pleased with the content, if not always her WiFi connection.

A promotional clip for Radius, a subscription digital video service that makes fitness experiences for streaming on tablets, phones, television and computers. (Radius)

With so many new alternatives available — most of them considerably cheaper than investing in another disc — of course Johnson and her fellow DVD devotees are straying. The only question is how much longer the market has before its final cool-down.

When historians study the fitness DVD era, they may be able to pinpoint its demise to March 11, 2014. That’s when Collage Video, which started hawking workout programs in 1987, shocked its die-hard fans with the news it was closing.

The site’s thorough reviews and preview snippets had made Collage the Web’s most trusted DVD source. But shoppers had been increasingly reading up on possible purchases, and then clicking over to Amazon or eBay to save money.

“The outlook was bleak,” admits Peter Castro, vice president of BayView Entertainment, a New Jersey studio that produces and distributes exercise videos. Rather than see one of its best customers go under, BayView purchased Collage and relaunched the site in June with a revamped look and lower prices.

Castro is convinced that if any segment of the DVD market has the stamina to survive, it’s fitness. Unlike movies or shows most people watch only a handful of times, workouts are often replayed daily. Fans generally want to experience them in a single location — often a living room or basement. Plus, the core customers aren’t especially tech-savvy, says Castro, who’s amazed how much business is still conducted through catalogues and by check. Until four years ago, he notes, Collage was selling VHS.

The older crowd that’s made “Scott Cole: Discover Tai Chi for Beginners” the company’s top seller isn’t going anywhere yet. And the collectors who follow certain instructors will always want the newest title, Castro says, pointing to the enduring success of Gilad Janklowicz thanks to his fans, called “Giladiators.”

“It ain’t over until the fit lady sings,” Castro says.

In fact, a report just released by market research company IBISWorld showed that the state of the fitness DVD industry is remarkably strong. Annual revenue is projected to jump 5.4 percent in 2014 to nearly $300 million. But those big numbers can’t mask the bad news: That’s the smallest increase in the last five years. And by all indications, this trend downward is unstoppable.

So even Collage will likely migrate — at least partially — to a streaming, subscription-based model, Castro says. He’s just not sure when, or how different it will look from the other Web sites jostling for the title of the “Netflix of fitness.”

The list of competitors keeps growing. Some are focused on one studio or instructor, such as Cathe Live, Suzanne Bowen Fitness and Barre3. Others are smorgasbord-style: DailyBurn, FitFusion, Vidergize, Booya Fitness, YogaGlo, Studio Sweat onDemand. The newest contender is Radius, from NBC Universal, which launched in December.

Although the workouts these outlets offer might not seem so drastically different from what’s on DVD, the online format is reshaping the industry.

Acacia is shifting its focus from DVDs to its streaming channel, and introducing new workouts every month from four different trainers, including yoga instructor Kristin McGee. (Acacia)

Acacia, a Silver Spring-based fitness brand, has shifted its focus from producing DVDs to its year-old Acacia TV platform. General Manager Allison Rand says it’s not merely a library, but “a fitness system.”

The technology allows Acacia to use metrics — “We know when they start the video, and when they stop,” Rand explains — to determine what viewers want. The company has already learned that shorter tends to be sweeter, so hour-long workouts are history, getting replaced by routines that last about 20 minutes. The goal is to be as responsive as possible: If a certain type of workout is getting more traction, Acacia can churn out more videos.

Because Web sites don’t need to deal with the manufacturing and distribution process, this stuff can be released much faster and at a much lower cost. “This allows us to have more fun,” says Rand, who wants to add specials that might have seemed too out-there for DVD.

Rand is also eager to build up an online community, which she believes will help Acacia TV adopt the vibe of a boutique gym. Viewers can check in with a motivational coach through its Facebook group. “Having a shelf full of DVDs is great,” she says, but people need guidance about what to do and how often.

For trainers, this digital world requires some adjustment. Yoga and Pilates guru Kristin McGee, part of Acacia TV’s new stable of talent, has been making videos since 2003’s “MTV Yoga.” At the time, the industry was shifting from VHS to DVD, but that technology change didn’t cause much of a shakeup. Now, however, McGee notices major differences.

“Because people are used to Instagram and YouTube, they want it raw. People don’t expect overly produced workouts anymore,” she says. If a hair fell out of place, McGee once knew that someone was about to yell, “CUT!” These days, it’s the opposite. On a recent shoot in Europe, a director even encouraged her to let a few swear words slip.

Janklowicz, whose “Bodies in Motion” TV show debuted in 1983, has been committed to multi-camera shoots with large crews on sets in Hawaii for his entire career. For the first time, he’s considering scaling back to fit in with what the rest of the industry is doing. “We might have to dumb ourselves down,” he laments.

But while they’re willing to adapt to the modern aesthetic, both trainers are concerned about quality control. The cost of producing a fitness DVD used to be so high that it wasn’t an option for most folks. Now anyone can shoot video, which provides opportunities for up-and-comers, but it puts an extra onus on viewers, says Angie Miller, a blogger for Collage.

“The younger generation doesn’t delve for credentials,” she says. “People are building an audience, but no one is checking whether they’re certified. If they look good, they get a following.”

There’s extra work for trainers these days, too. Releasing a few new DVDs a year isn’t enough to stay relevant.

This clip comes from Denise Austin's "Walk With Me" workout, which is part of her new 10 week, "360 degree" program. (Denise Austin’s 360 Plan)

That’s why exercise icon Denise Austin has spent the past year readying the debut of her 10-week 360 Plan. It’s recipes, motivational messages and hours of fitness content, customized for three fitness levels. “I had to film a lot more different choices,” Austin says. And although it’s available on DVD, she’s pushing fans to subscribe online — where they’ll also gain access to 100 episodes of her TV show.

To keep up with the trends, McGee has released her own app, and recently put together a 30-day program for the DoYouYoga blog. She’s also exploring the possibility of holding classes in real time.

Live seems to be the next step in the fitness video evolution. Peloton Cycle, which has been opening stores across the country, including a Tysons Corner location, sells an indoor exercise bike with a special feature. Its screen lets riders anywhere in the world “take” classes happening at a studio in New York.

But Janklowicz advises Johnson and other DVD fans not to give up on their collections just yet. “They won’t vanish off of your computer,” he says. He suspects his favorite fitness format has a future just like that of record albums.

“It’s not just for nostalgia,” Janklowicz says. “People like it.”

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