A novel vibration-induced exercise paradigm improves fitness and lipid metabolism of Caenorhabditis elegans.

Exercise has been known to reduce the risk of obesity and metabolic syndrome, but the mechanisms underlying many exercise benefits remain unclear. This is, in part, due to a lack of exercise paradigms in invertebrate model organisms that would allow rapid mechanistic studies to be conducted. Here we report a novel exercise paradigm in Caenorhabditis elegans (C. elegans) that can be implemented under standard laboratory conditions. Mechanical stimulus in the form of vibration was transduced to C. elegans grown on solid agar media using an acoustic actuator. One day post-exercise, the exercised animals showed greater physical fitness compared to the un-exercised controls. Despite having higher mitochondrial reactive oxygen species levels, no mitohormetic adaptations and lifespan extension were observed in the exercised animals. Nonetheless, exercised animals showed lower triacylglycerides (TAG) accumulation than the controls. Among the individual TAG species, the most significant changes were found in mono- and polyunsaturated fatty acid residues. Such alteration resulted in an overall lower double bond index and peroxidation index which measure susceptibility towards lipid peroxidation. These observations are consistent with findings from mammalian exercise literature, suggesting that exercise benefits are largely conserved across different animal models.