Both fitness and writing can be viewed as a journey, plus we make our characters take journeys all of the time to the point it's one of the basic known plots (or two). Don't forget to journey on over to A to Z Challenge and check out the other blogs.
Journeys are common in fiction. Just the act of creating the first draft and other drafts in order to get finish product is a journey the writer takes. Makes for a fitting topic because it's something people can relate too even if their journeys aren't as crazy or threatening as what we put our characters through. This can be a physical one for the characters, as travel is common, or it can be metaphorical or emotional. There are quite a few options. While the writer doesn't often travel, one might for research though, the journey one takes from the first words on the page to the end is quite an experience nonetheless.
Fiction can also influence a fitness journey.
Some fitness journey's use fiction as their influence, like walking. If you want, you can walk the distances traveled in certain books like Lord of the Rings. There are sites that list the exact distance from certain locations or you can do the whole long journey, one step at a time. One can use other books too. I would find it fun if I could remember to keep track of distances traveled to do one related to Wheel of Time.
The act of getting fit is also a journey one takes. There is a lot of effort, struggles, physical and emotional conflict and change that comes with the focus on health and fitness. There are also many rewards along the way.
Are you on a journey? Do you like to write about journeys?