Fitness websites are proliferating, offering a wide range of workout options from group classes to virtual personal training, and experts call the online venues especially inviting for the young, the time-pressed and the gym-averse.
And despite the lack of hands-on contact, the most popular sites manage to maintain the human touch, even if it is faceless and far away.
"I do think online fitness formats that have social community are successful," said exercise physiologist Jessica Matthews. "We know that social support is a long-term adherent to social activity."
Matthews, who teaches exercise science at Miramar College in San Diego, California, said for many people online fitness is about making connections and being with like-minded people.
Fitness instructor, trainer, and wellness coach Jessica Smith, who started streaming workouts in 2005, credits the connection established with her audience, mainly women 30 to 45 years old, for the success of JessicaSmithtv.com.
"That's what keeps people coming back and leaving comments," she added.
Even corporate gyms are dipping their toes into the video stream. Crunch, a national gym chain, launched Crunch Live at the end of 2013.
"We're hurtling so quickly through technology," said Donna Cyrus, a senior vice president of programming at Crunch Fitness. "It seemed to me the future was definitely online."
She said internet streaming is more cost-effective than purchasing a library of DVDs, and can reach consumers in rural areas too sparsely populated to support a brick-and-mortar gym.
Cyrus said many streamers are in their late 20s or early 30s, a generation comfortable online and less touchy-feely.
"This business, like everything else, is becoming less personal. People don't even talk on the phone anymore. They communicate on Facebook," she said. "Maybe this is an answer for those people."
Texting is how Florida-based personal trainer and health coach Lee Jordan communicates with clients scattered across the country. Most people he works with are morbidly obese, about 100 pounds (45 kilos) above their ideal weight.
Jordan, who has shed more than 275 pounds (124.7 kilos) through gastric band surgery, diet and exercise, knows how much support and encouragement are needed to achieve such a weight loss. He said text messaging and the power of the cellphone enable him to be in his clients' pockets all day long without coming off like an intimidating drill instructor.
"These people have experienced a lot of negatives and can be hypersensitive," he said. "In person they can shut down but via text they have a chance to read it, let it percolate, and respond."
His tools include "apps like MapMyWalk from MapMyFitness," Jordan explained. "My phone rings when they're done it and I can pull up what they did: how far, where. Then I can give them very specific feedback."
Neal I. Pire, a trainer and fitness expert with the American College of Sports Medicine, is for anything that gets anyone off the couch and moving. But he cautions that online tools are no substitute for the hands-on trainer.
"I don't think it's the ideal for anyone looking to do an exercise program," said Pire. "Even with a video cam to watch the client, it's hard for a trainer to be sure he's covering all the bases."
Whatever the shortcomings, most experts agree online fitness is here to stay.
Smith remembers when her long-term goal was to have a television show.
"Now I don't need one," she said.