Up until recently, I’ve been of the mindset that running is something you only do when being chased by a tiger. And, to some extent, I still believe that our bodies aren’t designed for the impact of shoe-covered feet smacking down on a hard surface. None of that has stopped me from starting a Couch to 5k regimen last week.

There are a number of variations on this approximately 10-week program to get a relative newcomer to jogging/running (i.e., me) up to shape by slightly increasing speeds and distances of jogs in intervals with walks over each week of the program. Pretty straightforward. The one I’m using — because the chart breaks down suggestions into easy-to-digest minutes — is this one, but they’re all about the same in that they provide a structured, but customizable, approach to starting on the road to running.

I started on my birthday last week (Aug. 4), and as of this morning, finished the third run of the second week. It’s hard, I’m not going to lie. In the first place, I hadn’t been to the gym in about two months (vacations, work, blah blah blah), though that’s the other thing I started in tandem with this C25K thing — regular gym visits again. But even when I normally did cardio activity at the gym, it would be about 30 minutes on an elliptical or 20 minutes on the treadmill, so 15 to 20 minutes running/walking didn’t sound so much of a challenge. Oh boy, was I wrong. Even though up to this point, the longest jog has been four minutes (this morning, buffered by about five minutes of walking on either side), it’s taken everything I have to keep my chest from exploding. As I write this, half an hour after finishing, I’m still a little wheezy. Dealing with things like wind resistance, hard running surfaces and — if you believe my GPS-based running software — elevation variations of up to 60 feet provide a much harsher experience than gliding along on a stationary elliptical trainer watching episodes of House.

But that’s good. I needed a challenge, a shake-up, a new routine to break the old routine of letting myself go. It’s forcing me to wake up before 6 a.m. every running day, even when I have nowhere else to be that day (much to the shock of my girlfriend, who is used to me sleeping in until about 10 a.m. on Sundays, and now I’m awake for hours before she is). It has me back on pace for the gym, where I can now focus more time on weight training, because I’m doing my cardio-intensive activity in the morning instead of cramming everything into one session. And I feel pretty good so far, no shin splints or knee pain or anything of the sort. My back is sore right now, but I think that’s a combination of the hard breathing and residual soreness from the back and shoulder work I did at the gym two days ago (my lower back is just fine). I’m even considering a half-marathon, something I’ve been talking about for years but never got around to doing.

Of course, this is only week two. When I get to the point where my plan has me trying to do 15 to 20 minutes of straight running, I’ll be easy to find: Just look for the guy lying down on the side of the road, crying.