One of the best ways for you to get outside on a pleasant afternoon is to spend a bit of time painting; many people think that they have to be a "painter," or that they have to have some semblance of talent with a paintbrush, in order for them to enjoy painting - but one of the best things of all about painting is the fact that you can go out to the park and splash colors on a canvas and enjoy yourself regardless of whether or not the painting looks good at all!
Photography is another great way for you to enjoy your time outdoors; once you start engaging in photography more and more often, you will start to see beauty that others fail to see, and this will make your time taking pictures that much more rewarding.
The idea of "exploring" the outdoors is something that many adults imagine is only for children, but this is also a great way for grownups to enjoy the outdoors; get outside and explore, searching for oddities and other interesting things worthy of your notice.
When you start to look for creative ways to get outdoors - instead of simply going outdoors blindly - you will not only be able to enjoy the outdoors more fully, but you will also be able to get outdoors as often as your body and mind require.