A few months ago, I expected to spend this weekend running my second half-marathon. One of the first things I did after running my first was find the next date to aim for, and I was excited to spend my winter and early spring training for an improved race time. Instead, I’ve spent it in physical therapy. In November I noticed an increasing pain in my left hip after my runs, and then, the day after a rainy December 10K, I couldn’t lift my leg to go up a stair or tie my shoe.

I expected PT to be physically difficult, but I wasn’t prepared for the mental and emotional strain that has proven far more challenging. Running had become a key part of managing the recurrent depression and anxiety I’ve had my entire adult life, and the sudden stop in exercise affected my mood much more profoundly than I anticipated.

I stopped running after that December race, hoping the injury would heal on its own. After a month, with my hip still painfully clicking and weakness in my upper leg, I finally took myself to a sports doctor, and started PT in mid-February. I got the go-ahead to try running only last week, meaning I’ve been essentially sedentary for four months. And nearly that entire time, I’ve felt off, like my life doesn’t quite fit. It makes sense: My brain had become accustomed to near-daily surges of the good-mood neurotransmitters associated with cardio exercise, and then the flow suddenly stopped, like quitting a drug cold turkey. (And like quitting a drug, stopping exercise can cause a kind of withdrawal.) But understanding what’s happening hasn’t made it any easier—explaining the cause of depression doesn’t mean I don’t feel depressed.

Oddly, though, I’m encouraged by how eager I am to get back out there. It means I’ve made a real change, from someone who doesn’t know how to take care of herself to someone who now finds it essential, from someone who gives up on new ideas and hobbies to someone who’s truly committed. Getting back to running won’t be simple: I need to change my stride to prevent reinjury, and I need to start back at the very short distances I’d long since moved on from. A younger me might have just given up, found a new hobby to pursue that didn’t have any baggage, any real challenges. But this time, I can’t wait to get started.