As if you weren’t beating yourself up enough already for taking that fourth “off day” of the week, now the stakes for athletic discipline have risen even higher as scientists have finally explained exactly why working out regularly will benefit your mind and body, aside from the killer abs.
On Jan. 26, a paper published in Nature by researchers at University of Texas Southwestern Medical Center detailed their study’s findings on the induced effects brought on by exercise. Data was collected from two strains of mice, one strain genetically engineered to be incapable of stimulation through physical activity or stress and the other strain left genetically unmodified. Using a green fluorescent protein (GFP) to tag and track the movement of units of cellular machinery known as autophagosomes’ throughout the mouse cells, the researchers were able to monitor the progress of a process taking place in the cells known as autophagy.
Autophagy is essentially the “clean-up” mechanism of a living cell. Specialized cellular machines called lysosomes eat and digest the waste products and cellular debris within a cell, recycling them into useable components. Autophagy not only disposes of harmful pathogens, protecting an organism from malevolent bacteria and diseases, but the lysosomal machinery, known as autophagosomes, also provides the
essential recycled materials necessary for a cell to survive and thrive.
When the rodents with unmutated DNA were put to work on a mouse-sized treadmill, the number of autophagosomes produced in the skeletal and cardiac muscle, as well as other organs, began to increase after 30 minutes of the vigorous exercise and reached a plateau after 80 minutes of continuous running.
The mutated mice, however, lacked an increase in autophagosomes during their workout, even after 80 minutes of running on the treadmill. These mice were genetically engineered with deformed BCL2-beclin-I complexes, anti-autophagy proteins which work as an “off switch” for the autophagy process. When the BCL2 complex, which is crucial to inducing autophagy, was disabled by scientists, the induced autophagy process was essentially set in a permanent “off” position. This meant that even with the mice engaging in vigorous exercise for extended periods of time, the increase in autophagosomes in the cell, and thus, the increase in cell self-cleaning autophagy of the cell, was almost completely negligible.
Aging effects occur as the normal autophagy process begins to fail over time and cell damage begins to accumulate. To better explain the mechanisms of exercise’s bodily benefits, the scientists of University of Texas Southwestern theorized that the autophagy process was extending the life of the mice by recycling old and worn-out mitochondrion. Mitochondria are the energy-producing “power plants” within a cell that sometimes mistakenly release harmful free radicals that damage the integrity of the cell. With an amplified autophagy process to ensure these mitochondria are being disposed of and are prevented from continuing to release free radicals into the cell, the aging process can be somewhat slowed.
Previous studies have shown that the stress of near-starvation increases the efficiency and efficacy of autophagy and mitochondria’s energy production, extending an organism’s lifespan. However, for those of us who prefer to live a prolonged life of fitness (with killer abs), rather than of starvation, perhaps we can forgo the no-food diet and sweat it out on the treadmill with satisfaction, keeping in mind exactly why our bodies will benefit more that way.