Couch potatoes everywhere will be rubbing their hands together when they hear that preventing weight gain need not involve a rigorous gym trip.
Indeed, if a paper in this week's PNAS has got it right, some of the vibrations from that hand rubbing might just be all the exercise they need. That's because New York researcher Clinton Rubin and his colleagues have found that a short daily stint on a vibrating platform resulted in mice that were much leaner than their less stimulated counterparts.
The researchers divided a group of similarly sized mice into two groups. One group were giving daily 15 minute vibration sessions. The platform on which they stood moved just 12 thousands of a millimetre up and down ninety times per second. The movement was just perceptible to a finger laid upon it. Other than not receiving vibration, the second group of control mice were otherwise treated identically to the first. After 15 weeks the results were striking. The vibrated mice had 23.5% less body fat than the controls and were 1.2g lighter, on average.
CT scans of the animals' bodies also confirmed 27% less fat around their middles'. To investigate where the fat was going the team used a third group of mice in which their bone marrow had been genetically programmed to produce a green coloured marker protein, enabling the researchers to track where cells produced by the bone marrow went in the body. Under normal circumstances at least a proportion of the cells turn into fat cells, called adipocytes.
But when the animals were vibrated the number of fat cells being produced fell, suggesting that the stimulus was in some way altering the fate of these cells and causing them to turn into other tissues. THe team suggest that this could lead to a non-strenuous drug-free method for obesity control.