Although we breathe mainly through our nose when resting, during exercise when we begin breathing harder, the air coming in is predominately supplied via the mouth. It may improve airflow through the nose, but there is no evidence that it reaches the lungs and boosts performance.

They could offer an advantage over normal lenses for sport by reducing the glare of light and sun.

It is no good squeezing all this extra activity into your day if you eat more than you need. But cut down on the calories you consume, accumulate more activity throughout the day and you are guaranteed to lose weight.

Using them can also strengthen the body through a range of motions by working across a number of different planes and through different directions. You can bend, twist and lean with them far more effectively to target muscles specific to different sports.