The study published by "PLoS One" involved taking biopsies from 25 volunteers aged 65 and over.

Traditional Chinese Medicine (TCM) has long taught that the Spleen is the main organ responsible for the absorption and production of Qi or the bodies energy. And recent investigations by TCM experts has provided strong correlations between the TCM concept of Spleen and the mitochondria in cells.

Mitochondria are often called "the powerhouses of the cells" because they produce most of the form of chemical energy used by the cells. Aging is associated with muscle atrophy (sarcopenia), weakness and functional impairment commences in the fourth decade of life when we begin to lose strength at about 1.0% per year, this loss accelerates with each passing decade. Some potential factors implicated in the functional decline of muscle include programmed cell death, oxidative stress, alterations in protein turnover, inflammation, hormonal dysregulation, disuse, and mitochondrial dysfunction.

The scientists involved in the "PLoS One" study expected to find some indication that the exercise program improved strength but didn't expect what they actually found. After six months of resistance training, there were dramatic changes at the genetic level.

As Melov puts it, "The genetic fingerprint [of the elderly participants] was reversed to that of younger people—not entirely, but enough to say that their genetic profile was more like that of young people than old people."

So this study supports the traditional understanding that appropriate exercise is good for you, it strengthens the Spleen and can help build your Qi levels however as in all things balance is required. TCM also teaches that excessive exercise can damage and drain the Qi and can injure the bodies Yin. This can be seen when people over train and become more susceptible to infection and injury, or in women who stop menstruating, sometimes it shows as insomnia and being hot or sweating in bed at night.