This browser does not support the Video element.
TAMPA (FOX 13) - While high-tech university labs use complex equipment, for exercise advice at home, many people are instead turning to their smart phone.
Dr. Francois Modave's team put of five the most popular free fitness apps to the test. He says out of more than 100,000 apps related to health and fitness, they chose from the top 50 on in the Apple store in April 2015.
Using guidelines from the American College of Sports Medicine to evaluate the apps, the team, including exercise physiologist Dr. Heather Vincent, said they were surprised.
"We knew that there was variation in the quality in the type of fitness apps that were available but we didn't realize just how much variation we were going to find," she said.
The team found almost all lacked key components of a well-rounded work out. Overall 90 percent added strength and resistance, 50 percent rated high in aerobics or cardio, but only 33 percent mentioned flexibility or stretching.
Out of a possible score of 10, most apps rated 5 or less. The Sworkit Lite Personal Trainer led the list with a score of 9.
"Our reaction was pretty positive. Being one of the only ones to pass their criteria was pretty great for us and what we had done and kind of some validation for some of the things we were doing," Sworkit co-creator Ryan Hannah told us.
Ryan, a former Army reservist, says they're using the study results to make the app even better. "So we are looking into building some of the warmups and cool downs and just kind of going from there."
Some personal trainers worry people using apps will lose motivation and increase their risk of injury.
"As far as the tools go, they are not going to teach you things while you are training, they are just going to tell you 'This is what you need to do,'" offered Downtown Tampa Powerhouse gym's Michael Hartzell. "Whereas a trainer would come in and ask, 'What did you have for breakfast?'"
Exercise specialist Jeff Plasschaert at the University of Florida wellness center says customers using fitness apps ask more questions, allowing him to correct their form. "The effect it has on the fitness industry is huge; it's definitely something we have to keep in mind and keep aware of."
"I use two different apps but they actually work together," explained Laura Zdziarski, who runs four times a week.
One app helps her track her runs. The other expands her workout.
"It gives you ideas of exercises that you thought you could do or you knew you were doing them before but it says, 'Hey try this aspect to it, add a rotation, or add a different component to change up the variability,' which makes the exercise a little more difficult and it makes it more fun."
While combining apps could help close guideline gaps, Dr. Mondave isn't ready to endorse any of the free apps he assessed.
"I don't think there is anything that is inclusive enough," he explained. "It's kind of like suggesting to buy a car, but there are some parts that are a little bit iffy. Would you recommend it? Probably not."
LINK: See the full list of graded iPhone apps