Sore muscles

Tracilea38

I have a question that relates to sore muscles....

I have never really been in shape. I have children and I keep active with them, but its not fitness active (if that makes sense lol)

Anyway, within the last 2 or 3 weeks I have started power walking, exercising and now I have added biking to it.....

I think I have been doing it gradually not starting too much too fast....but boy my muscles can feel it and once i added the biking a whole new set of muscles became sore lol

But despite the sore muscles.....my muscles feel stronger....like they have more energy. Like I can do more. Is this all in my head or are my muscles starting to get use to and maybe even like being used like this?