The science comes up short around several exercise products, but there are a few doctors do recommend.

The numbers are startling: More than one-third of adults in the United States are obese, and fewer than half of American adults actually get enough exercise.

Whether it’s a perceived lack of time or money or simply not a priority, keeping the body strong and healthy is just not happening for many Americans.

The number one internet search term for fitness remains “how to lose weight fast,” and people are looking to fad diets or products to help them with a quick fix.

There’s an entire industry dedicated to fitness accessories — items that promise to help you burn more calories, build muscle, and look leaner with little effort or consistency.

Consumers are ready to shell out the money. But do these products actually do what they claim?

Healthline asked doctors for their opinions on some of the most popular health and fitness accessories on the market today.

Modius headset: It’s all in your head, claims Modius. They claim their new headset will help you run faster, cycle farther, train harder, and even lose weight. All for $499.

The verdict: Current studies have been too short to prove results. As people typically begin to regain weight after six months, the company’s 16-week study doesn’t allow enough time to prove long-term results. Plus, according to a recent article on The Verge, the headset can also create a swaying motion, similar to the feel of motion sickness.

Tom Brady’s TB12 vibrating foam roller: Football legend Tom Brady wants you to spend $200 to “enhance your pliability pre- and post-workout” with a vibrating foam roller that features a rechargeable lithium-ion battery at its core. He claims the three vibration intensity levels will help maximize effectiveness as you work to lengthen and soften your muscles.

The verdict: The best thing you can do to lengthen your muscles is stretching, according to Dr. Peter Holmes, an orthopedic surgeon specializing in sports medicine. “I have never been a fan of passively rolling muscles to stretch them. It feels good, but it’s not as good as a quadriceps or hamstring stretch. Foam rollers don’t stretch your muscles. They just compress it lightly from the outside,” he explained.

“If you add vibration, I’m sure it feels great, but there’s no proof that a vibration will add to the stretch.”

Sauna suits: Made by a variety of manufacturers, sauna suits are designed to trap body heat, increasing the body’s core temperature during a workout. Brands like Kutting Weight claim that wearing their body-covering suits while exercising will increase metabolism and facilitate more weight loss.

The verdict: Sweating doesn’t significantly increase the number of calories burned, and these $70 suits could actually cause dehydration or heat exhaustion.

“If you are on the elliptical and burning 12 calories per minute, then you are sweating the way you are supposed to,” Holmes reminded us. “What are you adding besides the potential for hyperthermia? You are trying to fool Mother Nature, and that’s not safe.”

The Flex Belt: The Flex Belt claims to provide an “effective abdominal workout” in 30 minutes a day for people who are too busy or tired to complete a traditional abdominal workout. Strap on the belt, and electronic signals will stimulate the nerves that make your muscles contract and relax.

The verdict: This could be an addition to abdominal strengthening exercises, but it’s not a substitute. “So much of ab appearance and results are nutrition related, so in combination with the right diet and abdominal exercise routine, these pads could add some extra muscle stimulation,” explained Dr. Arun Rajaram, an orthopedic surgeon specializing in sports medicine. “Doing resistance training and having the right nutrition is what will decrease the abdominal fat and increase the overall appearance of your abdominal muscles.”

If someone is ready to make changes to their diet and exercise routine, this could be used as a boost. One belt goes for $199.

Smart Underwear: Developed by a team of Vanderbilt University engineers, this undergarment will supposedly remove stress from the lower back when the user double taps to turn it on. The device isn’t yet available to the public.

The verdict: This brace, like many others, allows the core muscles that support and stabilize the spine to disengage. When this happens, the muscle weakens, causing more stress on the spine and the likelihood of experiencing pain, according to Tonic.

Sweet Sweat Stick: The makers of this topical gel instruct users to rub it on “problem and injured areas” prior to exercise. They claim that it’ll improve circulation, motivation, and sweat during exercise. Why sweat? Because sweat helps you burn calories, according to the founders.

The verdict: According to Rajaram, the ingredients can warm up an injured area, improving blood flow and muscle and joint function.

But “just because something makes you sweat, it doesn’t automatically mean you are getting a better workout,” Rajaram explained. In fact, sweating is the body’s natural way of regulating body temperature, and it doesn’t actually burn a measurable number of calories. It’s simply a way to temporarily lose water weight, which is quickly regained once you properly hydrate.

Simply Fit Board: The curved board presents a balance challenge. The company, funded by a Shark Tank investor, recommends you twist back and forth to get a great cardio and ab workout.

The verdict: This might be one of the most legitimate infomercial products. “I think this could be a good exercise,” Holmes said. “One of the things it may help is teaching proprioception, which can help prevent injuries. It can also help with balance and core strength, and it may decrease some injuries.”

Black Box VR: Black Box calls itself the first virtual reality gym.This virtual reality headset leads you through a host of different immersive gaming experiences. You get a full-body workout that combines resistance training and high-intensity cardio while staying engaged.

The verdict: “This is another version of a home exercise video, but with more of an immersion experience thanks to the virtual reality,” explained Rajaram. “It’s similar to Peloton bikes, where you’re watching a live class on the screen. But, if you aren’t using the correct form, you could injure yourself. I recommend you get guidance on how to properly use resistance bands before you start doing it at home.”