Just as scientists are attempting to build calorie restriction mimetics to recapture the well-studied benefits of eating fewer calories, so too some research groups are in search of ways to replicate the benefits of exercise. These efforts are nowhere near as far along as calorie restriction mimetic studies, but I expect that the field will grow in the years ahead. Here is an example of present work, which is still very much at the stage of discovering important mechanisms that might later be manipulated:
In the last few years, the benefits of short, intense workouts have been extolled by both researchers and exercise fans as something of a metabolic panacea. In a new study, [scientists] confirm that there is something molecularly unique about intense exercise: the activation of a single protein. The study revealed the effects of a protein known as CRTC2. The scientists were able to show that following high-intensity exercise, which enlists the sympathetic nervous system's "fight or flight" response, CRTC2 integrates signals from two different pathways - the adrenaline pathway and the calcium pathway, to direct muscle adaptation and growth only in the contracting muscle.
Using mice genetically modified to conditionally express CRTC2, the scientists showed that molecular changes occurred that emulated exercised muscles in the absence of exercise. "The sympathetic nervous system gets turned on during intense exercise, but many had believed it wasn't specific enough to drive specific adaptations in exercised muscle. Our findings show that not only does it target those specific muscles, but it improves them - the long-term benefits correlate with the intensity of the workout."
In the genetically altered animal models, this resulted in a muscle size increase of approximately 15 percent. Metabolic parameters, indicating the amount of fuel available to the muscles, also increased substantially - triglycerides went up 48 percent, while glycogen supplies rose by a startling 121 percent. In an exercise stress test, the genetically altered animals improved 103 percent after the gene was activated, compared to an 8.5-percent improvement in normal animals.