Hey Fitness Fanatics, You Might Not Want to Rely on Your iPhone For Results

Want to get in shape? As it turns out, there’s not exactly an app for that — at least, not one that scientists are ready to fully endorse. As per a new study conducted by researchers at the University of Florida, effectively none of the top 30 most popular exercise apps available on your iPhone are actually satisfactory when it comes to meeting the guidelines set by the American College of Sports Medicine (ACSM), and that’s not inspiring much confidence among either experts or users. When scored against a system where the perfect rating is a 14, only one app, Sworkit Lite Personal Workout, even came close with a score of 9.01. Its nearest competitor, 7 Minute Workout, only garnered 5.39 points.

In assessing these apps’ effectiveness, scientists looked at a few key metrics as set forth by the ACSM, including warm-ups, cool-downs, and safe stretching. They were then assigned scores for three distinct categories — aerobic exercise, strength and/or resistance, and flexibility.

Related: Apple goes all in on health with Fitness and Workout apps

The results were a touch disheartening — while over 50 percent of the apps were acceptable when it came to aerobic exercise and the vast majority of them (90 percent) had users doing some sort of strength and resistance exercises, very few of them took the final, and equally important category into consideration — flexibility. As per findings published in the Journal of Medical Internet Research, around 67 percent “did not meet any flexibility criteria,” leaving a key part of your workout in the dust.

Francois Modave, lead author of the study, told the Washington Post, “The issues with these apps place users at risk for injury because the apps fail to prepare them to take on the exercises, use proper techniques and address safety issues.” And given that only Sworkit Lite Personal Workout met even half of the necessary criterion for safe and effective exercise, there’s quite of bit of risk involved.

Nike+ Training Club, a popular app, received a rating of only 3.11, and superstar trainer Jillian Michaels Slim-Down received an even more abysmal score of 1.43. For the full list of ratings, check out this chart by the Washington Post.

Of course, companies aren’t accepting these sad numbers without a fight. Johnson & Johnson disputed its own low score of 2.44, telling the Post that such a representation “does not appear to be a fair or accurate rating and assessment” of its workout app. But as Richard Cotton, national director of certification for the American College of Sports Medicine, points out, having a low score isn’t the end of the world. After all, this shouldn’t be the only exercise regimen you’re following.

Said Cotton, “We encourage everyone to look for the technology support most appropriate to their goals and needs, and for the industry overall to continue its impressive progress, stimulated by such things as this study.”