International Day of Happiness: 5 healthy activities that boost happiness

If the first day of spring and the free Rita's water ice isn't enough to make you happy, Thursday March 20th is also the 2nd Annual International Day of Happiness.

So today, we give you five healthy activities that are scientifically proven to boost your happiness:

Exercise. You know that happy feeling you get after a long run or hard workout? The one that makes you feel like you can conquer just about anything — you can thank endorphins for that. Endorphins are your brain's feel-good neurotransmitters and physical activity helps pump up their production.

Meditate. Breathe in and breathe out to achieve the ultimate level of happiness. In 2011, an explosion of new research indicated that meditation could physically change the brain to make you happier. In one study, a research team from Massachusetts General Hospital found that after completing an eight-week meditation course, parts of the participants' brains associated with compassion and self-awareness grew, and parts associated with stress shrank.

Have sex. A 2013 study published by the Institute for the Study of Labor reported that yes, sexual activity does indeed have a strong correlation with happiness. (As if, you didn't know that already…) Plus, the researcher revealed that those who had more frequent sexual activity also had lower rates of arthritis, heart disease, and diabetes.

Volunteer. Helping others live happier lives could go a long way towards helping yourself become happier. A 2013 University of Exeter study found that volunteers reported lower levels of depression, increased life satisfaction and enhanced well-being.

Take a nap. Who doesn't feel happier and more willing to take on the day when they're well rested? The authors of a 2009 study published in the Journal of Sleep Research confirmed that naps are beneficial for mood enhancement in healthy adults.