Spend time in the outdoors!

Spend at least half an hour outside every day. Go for a walk, run or exercise – even if it's cloudy, you get more intense light than in the average workplace, and fresh air makes you more alert. If you have the opportunity to spend time in nature or a park, this is another way to reduce stress, as greenery has a relaxing effect on many people. 

Why it helps:
The air outside is often more oxygen-rich than indoors, which can give you an energy boost. Sunlight also triggers the body's production of vitamin D, which helps strengthen your bones and immune system.