Wim Hof, who holds a Guinness world record for the longest time swimming under ice, immerses himself in ice water during a 2010 event to raise public awareness of global warming. Photo: Tyrone Siu/REUTERS

There may be a third pillar of physical fitness beyond diet and exercise

The theory suggests that our bodies might need environmental stress if we are to reach our full potential

Topic |   Business Insider

TOP PICKS

Wim Hof, who holds a Guinness world record for the longest time swimming under ice, immerses himself in ice water during a 2010 event to raise public awareness of global warming. Photo: Tyrone Siu/REUTERS
READ FULL ARTICLE