If you’ve ever seen those sneakers that look like gloves for the feet and wondered if you should try them out, you’re not alone. Over the past few years barefoot sport shoes like Adidas adiPURE Barefoot and Vibram FiveFingers have been gaining popularity, touting promises of a more efficient and natural running experience. But do the shoes really live up to their hype or are they a health hazard waiting to happen?

Unfortunately there is no clear answer. While some studies conclude that the footwear prevents injury by fine tuning runners’ form, other findings show that the shoes cause heel and metatarsal stress fractures among other injuries —especially in less experienced runners who transition into wearing the shoes from traditional footwear too quickly.

While there is no concrete evidence that a slow transition from regular shoes to minimalistic footwear can help prevent injury, it is a smart precaution, says Joseph Grillo, DPM, FACFAS, a podiatrist specializing in sports medicine in Fort Myers, Florida. The amount of time it takes for a person to be able to transition into the shoes safely varies based on foot and body type, age, weight and fitness level, he notes, and it’s not uncommon for it to take months, even years to be able to do the majority of running safely in barefoot-style shoe.

Want to make the transition but not sure how to get started? Begin by walking a few minutes a day in barefoot shoes, slowly building up to one, two and three hour strolls. Once walking is comfortable, transition into short runs, gradually adding mileage. In addition to a slow transition into the shoes, Vibram recommends that their consumers complete a barefoot acclimatization program which includes sensory exercises and foot strengthening moves like heel raises, toe grips and toe spreads. While some five finger fans swear by these exercises to avoid injury, Grillo isn’t convinced strengthening exercises lowers the risk. When runners accustomed to a supportive shoe with heel elevation transition into a minimalistic shoe the risk for injury is high, he notes.

Although it’s possible for advanced runners in tip-top shape to transition into the shoes safely, these are not the right shoes for amateurs or weekend warriors, and certain people should avoid the shoes at all costs, says Grillo. People with a high arch or extremely flatfoot or a tight Achilles heel should stick to traditional footwear, as they may have a particularly difficult time adapting to the support-lacking shoes. Consumers who are overweight, or have osteoporosis or osteoarthritis should also steer clear.