Can an app replace a personal trainer?

Fitness apps designed to serve as surrogate personal trainers are a dime a dozen - except, of course, for those that cost $29.99 per year. That price is steep in the app world but is much better than a trainer's hourly rate of $50 or more.

Such cost savings are a big reason people are turning to apps that show videos, pictures and diagrams of weightlifting moves, yoga poses, running techniques and cycling routines. Another is time. With an app, there's no worrying about scheduling appointments; the trainer is right there in your pocket, ready whenever you are. Another benefit is that apps can be less intimidating than human trainers.

"If it does anything to get you off the couch or get you motivated and get you moving in some way, shape or form, then I think that's a pro to an app," said Isiah Munoz, personal training manager at Vida Fitness.

But that could be a con if you don't know how to move correctly (read: safely). Fitness apps often demo the beginning and end of an exercise, leaving out the range of motion in between, said Susie Zender, a personal trainer at Vida. On biceps curls, they probably aren't telling you, " 'Keep your shoulders back, compress your scapula, keep your elbows forward,' " she said.

Apps also can't address issues such as pre-existing medical conditions, added Sean Hanrahan, personal training manager at Equinox Sports Club. "With personal training, it's the 'personal' that we put into it to individualize the aspect of what's needed for a client," Hanrahan said.

But the pros aren't anti-app. Hanrahan said he uses apps to supplement his clients' sessions and keep them exercising during the 167 hours per week they're not with him. Munoz suggested laying the foundation for safe exercising with a trainer and then using apps.

Some reports peg the number of available fitness apps in the six digits, which means finding the best one can take some heavy lifting. Look for the company, organization or person behind the app, checking for brand or name recognition and instructors with certifications from places such as the American Council on Exercise and American College of Sports Medicine. Also read apps' ratings, user feedback and update history, Hanrahan said. Those can tell you whether you'll have to navigate many screens or will be hit with offers to pay more to access more, for instance.

Apps can't compete with a trainer's experience and interaction, but they can be a quick, accessible and inexpensive way to get inspired to move.