She was nicknamed 'The Body' by Time magazine in 1989. And Australian supermodel Elle Macpherson revealed one of the secrets behind her enviable figure in a post shared to her Instagram Story on Thursday.

The 55-year-old shared a photo of herself in a portable infrared sauna, that looked more like a sumo wrestler suit, and plugged its many health benefits.

'Sauna time,' Elle captioned the picture, which saw her slipping her slender frame into a padded white sauna with infrared light panels.

Her fair locks were swept up into a topknot, and she looked to have gone makeup-free, allowing her natural beauty to shine through.

The mother-of-two went on to list numerous health benefits in her caption, including the elimination of toxins from the body and 'stimulating lymphatic drainage'.

According to Therasage's website, the $1,400 (AUD) sauna 'enhances cell energy and blood circulation, relieves pain and burns calories'.

This is not the first time Elle has shared her body secrets, revealing to Instagram fans in October that she regularly has lymphatic drainage treatments.