In 2006, Renato Valdés Olmos weighed 320 lbs. "Dude, you will die of heart disease or worse before your 30th birthday," he admitted to himself before embarking on a massive effort to lose 150 lbs over the next three years. Olmos succeeded, no thanks to fitness gadgets, only a few of which existed at the time aside from simple pedometers. Today, wearable technology is all the rage, like the Nike+ FuelBand and apps like Moves that live inside your phone — but Olmos is convinced that there's an easier way to stay healthy, and it doesn't involve counting your steps.

"What is the single best thing we can do for our health?"

In 2011, Olmos stumbled upon a web lecture by Dr. Mike Evans called "23 and a 1/2 hours." Evans asked, "What is the single best thing we can do for our health?" He concluded that 30 minutes per day of exercise — even just a few leisurely walks — can dramatically decrease your risk of getting just about everything from heart disease to arthritis to high blood pressure. Moving 30 minutes per day can decrease an obese person's chance of getting Type 2 Diabetes by 50 percent, Olmos learned. It seemed that nature attached a magical significance to 30 minutes. Once subjects exceeded 30 minutes per day, they saw diminishing returns for each additional minute spent exercising.

Olmos spent the last year building Human, an iPhone app built on Evans' premise. Unlike the Nike+ FuelBand, which counts your exercise using "Fuel Points," or Moves, a popular app which counts your steps or distance travelled, Human uses a concrete goal anybody can understand: 30 minutes of exercise per day. Here lies the key, says Olmos, a one-time obese individual, to getting off the couch and starting to feel better.

Like Moves and other fitness apps, Human tracks your phone's location and estimates how many minutes you've moved each day. The app also lets you quickly input periods of activity like 30 minutes of working out in a gym. If you're running short, the app might nudge you to take a walk after lunch or dinner. The difference is that where the FuelBand obfuscates your day's exercise by indicating you're 350 points short of your daily target, Human simply says "Take a 15 minute walk and you're done for the day."

30 minutes might not sound like very much exercise, but some studies indicate that the average American between the ages of 18 and 64 might move for as little as 17 minutes per day. "It's almost too simple to succeed," Olmos says, and the evidence is mounting. "Aim for at least 30 minutes of physical activity every day," says Dr. Edward Laskowski, co-director of the Mayo Clinic Sports Medicine Center. Moving for more than 30 minutes per day certainly can't hurt, but when most Americans don't even make it that far, a few daily walks already sounds like a noble goal. Plus, the app is simple enough that your mom and dad can use it.

A man "gets all the walk that he requires in half an hour," wrote Thoreau

In our tests, Human wasn't as accurate as Moves at parsing your movements around town, but whereas we got bored of Moves after a few weeks, Human remained compelling because of the simple goal it presents you each day. Also, since it's built into your phone and not into a rechargeable wristband like the FuelBand, it requires little extra effort to keep up using it. "Moves is a fantastic app," says Olmos, "but it doesn't really solve a problem yet. It's for people who are already into quantified self and want every aspect of the day meticulously tracked." Human, on the other hand, provides a very tangible goal without any tacky gamification mechanics to help you reach it, because ultimately, the decision to take a walk is completely up to you.

"The Daily 30," Human's moniker for its get-healthy-quick regimen, is "the best form of preventative medicine," the company says. If the tagline sounds familiar, it's probably because you've heard Greek physican Hippocrates' famous line: "Walking is man's best medicine." An app might never be able to administer the vital dosage of exercise, but at least now, it's dead simple to keep count in conventional terms, not abstract ones. After testing a number of fitness gadgets, reviewer Dann Berg decided to use both the RunKeeper app for run tracking and the Fitbit Zip for an overall sense of his daily activity levels. Human operates on a different philosophy — one that anyone can get on board with. For fitness fanatics, Human is very likely a bit too pedestrian and inaccurate, but for the rest of us, it makes getting off your butt for even a few minutes feel like it's actually worth it.