In the future, couch potatoes may get all the benefits of exercise without having to set foot in a gym.
Scientists believe they have discovered a protein that occurs naturally during workouts and could be developed as a pill to keep muscles strong.
The protein is called Sestrin and a study performed on mice and flies found that administering it resulted in them burning fat and gaining muscle even without exercise.
Humans produce the same protein and researchers think that making a supplement of it could help reduce muscle wastage in elderly or inactive people.
‘Sestrin alone is sufficient to produce many benefits of physical movement and exercise,’ said Dr Myungjin Kim, who led the research into the protein at Michigan University in the US.
In order to track the protein’s effectiveness in flies, the research team built a tiny fly treadmill – utilising the flies’ instinct to climb up and out of a test tube. The flies were monitored over three weeks and the team then compared the results with flies that were bred without the ability to produce Sestrin.
‘Flies can usually run around four to six hours at this point and the normal flies’ abilities improved over that period. The flies without Sestrin did not improve with exercise,’ Dr Kim said.
When they artificially boosted normal flies’ Sestrin levels to the maximum the flies’ results were stronger – even without exercise – than the trained flies.
Dr Kim added: ‘We propose that Sestrin can coordinate these biological activities by turning on or off different metabolic pathways. This kind of combined effect is important for producing exercise’s effects.’
The researchers also helped another collaborator to demonstrate that muscle-specific Sestrin can also help prevent atrophy in immobilised muscle, including the type that occurs when a limb is in a cast for long periods.
Dr Kim said: ‘This independent study again highlights that Sestrin alone is sufficient to produce many benefits of physical movement and exercise.’
But the researchers caution that it’ll be a while until we see any kind of Sestrin pill on the horizon.
Dr Kim said: ‘Sestrins are not small molecules, but we are working to find small molecule modulators of Sestrin.’
The research was published in the journal Nature Communications .