My favorite Super Bowl commercial was the VW Dog Strikes Back - the one with the overweight dog. I suppose they threw in the Star Wars portion and the "Vader kid" for another "strikes back" reminder. The commercial is great because it captures the essence of a return from being out of shape: going from lying on the couch, not being able to fit through the dog door to stair climbing, weight training, aerobics, avoiding extra food, swimming and finally making it outside to do fun things such as run beside the car. The commercial touches on two of the things I love - dogs and exercise. It sends an underlying message - you can do it and it will feel great when you get it done.

We've written a number of blog posts on the benefits of exercise, including how exercise protects against disease such as metabolic disease and diabetes. Some of our blog posts on exercise include On Finding Time and Making Exercise Happen, Spring's Around the Corner, The Fountain of Youth Discovered and Exercise Protects Against Disease. These blog posts reference research providing ample evidence that exercise does work to help the body. The thing is, the scientists, just didn't know exactly how.

A study published online last week in Nature has shed some light on how exercise helps the body to stay healthy. Since the 1960's scientists have known about a cell function known as autophagy. Autophagy is the process within a cell that takes parts of the cell damaged through normal wear and tear and either recycles the cellular material or burns it as fuel. Clearing out damaged cellular debris is a necessary cell function to keep the cell healthy and working effectively. Autophagy is also the process that allows a starving cell to reallocate nutrients from unnecessary processes to more-essential processes.

In the study, researchers used mice to see how exercise affected autophagy. Some mice in the study were genetically engineered so that the their cells didn't have autophagic processes to remove debris during exercise. These “hoarder” mice grew tired whenever they exercised and the mice had difficulty using sugar to fuel their muscles.

The researchers also found that when diabetes was induced in these mice—by giving them too much fatty food—exercise had no effect on the disease. Unaltered mice, however, could reverse their diabetes by running, even if they kept eating poorly. Now, the purpose of exercise isn't to be able to eat poorly and still avoid disease. Dr. Grandma has also written blog posts -- Feet, Forks and Fat - Protecting Our Children is a great one -- about how easy it is to out eat the calories that exercise burns. Also, it is important to note the research focused on exercise and metabolic disease, not other diseases associated with being overweight such as cardiovascular disease or arthritis.

If exercise alone provides such great benefits for your body, just think how great you will feel and look if you exercise and eat healthy foods. Increasing vegetables in your diet and cutting out added sugars and other high-calorie, low nutrient foods can make a huge difference. Dr. Grandma's recipes are a great place to start in creating a healthy diet.