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More reasons to head outdoors

It spurs cancer-fighting cells

Some research suggests that when people are in nature, they inhale aromatic compounds from plants called phytoncides. These can increase their number of natural killer cells, a type of white blood cell that supports the immune system and is linked with a lower risk of cancer. These cells are also believed to be important in fighting infections and inflammation, a common marker of disease.

In one study, researchers found that people who took a long walk through a forest for two days in a row increased their natural killer cells by 50% and the activity of these cells by 56%. Those activity levels also remained 23% higher than usual for the month following those walks.

• It’s just more fun

When people exercise outside, they feel better and enjoy the exercise more, studies suggest

A review of research found that people who exercised outside reported feeling more revitalized, engaged and energized than those who did it indoors. The researchers also found that people who exercised outside felt less tension, anger and depression.

It’s calming

Nature has a way of making people feel calm and exercising outside can strengthen that effect. A small 2015 study found that people who walked for 90 minutes outside were less likely to ruminate on their problems and had less activity in the brain area linked to depression, compared to people who took similar walks but in urban areas.