That is the aim of life: to become an adult while remaining a child at heart.  Play is the key.  When we play, we do things because we want to, without thought of payment. – Dr. George Sheehan

It's so crucial for our wellbeing to have play in our life.  Time spent doing something, not for the product, but rather for its own sake.  Kids don't "exercise", they play.  They run around with their friends, engaged in spontaneous bouts of movement for movement's sake. 

As adults we must find ways to play.  It might look different than it did during our childhood, but it should have the same spirit.  With the normalization of workaholism, it's common for us to feel like we're doing something wrong if we're not being productive.  Sure, work hard when you're at work, but have boundaries with your time.  There is no need to work 24/7.   You'll find yourself recharged for your work when you balance it with play.

If you feel lost in regards to what your form of play could be, think back to childhood.  What activities did you enjoy then?  Are there ways to capture the same spirit now?  Can you involve your family or friends to make it social?  Get creative!