While people are becoming more dependent on high-tech gadgets in many areas of life, fitness experts say they are turning back to basics for their workout routines.
They see more exercisers shedding prop-heavy fitness classes for short-burst, equipment-free workouts.
"It's my theory that we've hit a critical mass in group fitness," said Donna Cyrus, senior vice president of programming Crunch Fitness. "Mats, Bosu (stability) balls, body bars: by the time you put all this stuff on the floor it's 10 minutes into your workout."
These days, Cyrus said, most successful fitness classes require very little equipment and many are 30 minutes long, down from the hour or more that was standard a few years ago.
She chalks it up to the time saving necessitated by the 24/7-connected world.
"With every minute taken up by social media, and people never out of a working state, (it's) a way for people to get these workouts in," she explained.
Cyrus' observation are supported by a recent survey by the American College of Sports Medicine, which predicted High Intensity Interval Training and bodyweight training will be the top two fitness trends of 2014.
"It appears that people are going back to basics," said Dr. Walter Thompson of ASCM, which has conducted the survey since 2008.
He said HIIT, which involves short bursts of activity followed by a short rest or recovery, jumped to the top of the list in its first appearance in the poll about fitness trends, which was completed by 3,815 health and fitness professionals worldwide.
Thompson believes the shaky economy favors what he calls "low-cost delivery programs" such as HIIT bodyweight training.
"Folks just can't afford to go to specialized exercise programs," he said, noting that neither Pilates nor Zumba are predicted to trend in 2014.
"Retention data shows that people get bored with an exercise program in three to six months if they're not challenged or the program is not varied enough," he explained.
The exception is yoga, which still popular.
"The yoga folks change it enough to maintain interest," he said of the ancient practice that has spawned countless variations from power yoga and prenatal yoga to hot yoga.
Andy Smith, chief executive of Daily Burn, which streams a variety of workout programs to some three million subscribers, said modern bodyweight training borrows freely from seemingly unrelated genres, such as wrestling and mixed martial arts.
"People used to think of bodyweight training as just push-ups but there's a lot more emphasis on mobility and work on the ground," he said. "I don't think of calisthenics, I think of other things."
He sees the renewed interest in HIIT as part of a larger turn towards functional fitness and away from the model of "aesthetic" training, typified by the body builder.
"There's a renewed interest in functional training, (or) training for everyday life," he explained. "You don't have to be ripped, but fit to perform everyday tasks."
Smith, whose background is in HIIT, applauds the intensity of the workout.
"Most people tend to under train rather than over train. So something that pushes you to another level is good, so long as you mitigate the risk of injury," he said about HIIT.
But he added that HIIT comes with a lot of cautions.
"It's not for a person unaccustomed to exercise," he said. "I wouldn't want a 67-year old dad doing HIIT, but for a 22-year-old who lifts weights, why not?
Nevertheless HIIT's sudden popularity surprised him.
"It's a time thing. It's a challenge for young folks," he said. "A guy like me, I'm happy jogging."