With ad revenues slipping in the past year, magazines have been trying to find new ways to earn money and keep their publications afloat. With its latest idea, Men's Health might be on to something.

Using new technology only made possible with Apple Inc.'s iPhone operating system upgrade this week, the magazine has launched an iPhone application that sells additional content through the app itself.

The "Men's Health Workouts" app, which is available for $1.99, "comes with photos, instructions and the ability to track one's progress for 18 workouts and more than 125 exercises," explains AdAge.com's Nat Ives. However, users can purchase additional workouts and other info -- for as little as 99 cents.

According to Apple, this approach to apps is revolutionary, but its probably not the last time we'll see a magazine use this new technology to sell additional content to readers and iPhone users.

Earlier this week, we spoke exclusively with Wired Editor-in-Chief Chris Anderson about new ways magazines and newspapers can monetize content. Something tells us Anderson would be very intrigued by Men's Health's new model.

"It's not about charging more for the same products, but releasing different products," Anderson told FBNY. "[Those products] are not for everybody, but for enough people that we can charge a higher price."

Update: In a press release today, the magazine said the app "includes 18 exclusive workouts and 125+ exercises from the world's top strength coaches, athletes, and fitness experts. Each workout features step-by-step instructions, high-quality photos, advanced logging functions, and is powered by a one-of-kind circuit training interface." The additional content available for purchase will be workout "expansion packs" including additional groups of workouts directly within the application itself. Available expansion packs at launch include, "The Ultimate Abs Pack," "Build a Beach Ready Body," and "Huge Arms in a Hurry."

"Men's Health is leading the industry by adapting our print products to emerging digital platforms," said David Zinczenko, the magazine's editor-in-chief. "While other magazines have offered iPhone applications before, we are the first to embrace Apple's In-App purchase function, and in doing so, we are the first to deviate from these traditional marketing methods. In essence, we are creating a distribution channel within the iPhone for our content."