Practice, definitely makes perfect with coding. However, I wouldn't look at it like exercise. I'd look at it more like a series of races. Start with a 1-mile race, then a few 5ks, then a 8k, then a 10k, etc.
The difference, unlike exercise is that there is an end product. This means, instead of 'just coding' each day, I would focus on completing projects.
Here is an example of what I mean to maybe start with: https://50reactprojects.com/