Spend Time in Nature

This is a pledge for everyone to take 20 minutes out of their day and go outside in nature. Whether it is in your backyard, the park, or forest. Do whatever you want - sit and relax, have a picnic, read a book, go for a walk, do some gardening, etc. As long as you're outside, it will do you good.
According to the article, "Spending Time in Nature Makes People Feel More Alive", being outside in nature for just 20 minutes a day was enough to significantly boost vitality levels, the research finds.

When you feel sluggish, instead of reaching for an energy drink or coffee, go outside instead. Lead author/Professor, Richard Ryan says, "Nature is fuel for the soul. A better way to get energized is to connect with nature, " he says.

Sources:

Spending Time in Nature Makes People Feel More Alive, Study Shows

How to Increase Energy Naturally