If I’ve learned anything over the past ten years about rollerblading in Central Park, it’s that your level of enjoyment is directly proportional to your powers of anticipation and forecasting. Stated more succinctly: while whizzing around the loop, it’s important to keep your eyes open and be aware of everything that’s going on around you. Is that couple walking to the Boathouse going to get all the way across the loop before you reach them, or should you start figuring out a path around them that minimizes your loss of momentum? When you reach that clot of people extending all the way across the exercise lane, will their relative speed differences have created a manageable path through the blockade, or should you be looking for a spot to hop onto the sidewalk and zip right by them? Is that woman walking with the stroller going to continue to weave around on the roadway, and if so, are you both destined for the same patch of asphalt at the same time? (Alternately, is that woman with the stroller going to suddenly realize that the big, paved sidewalk immediately inside the loop was built so that people wouldn’t stroll in the exercise lanes of the roadway?)

And if that’s all not hard enough, there are certain times during the day that Central Park is open to cars, meaning that venturing out of the third of the road limited to bikers, bladers, and runners is an invitation to become either a hood ornament or road kill. If you’ve ever crossed an intersection on foot in NYC, you know that the likelihood of anticipating the future path of a cab is similar to that of hitting the Powerball; when you’re traveling 15 miles an hour on an unstable base of inline wheels, and the line separating you from the cab is only four inches thick, doing so takes on a whole new level of importance. Is that cab going to use the exercise lane to pass that Parks Department truck he’s been riding tight for a quarter-mile? Do you need to speed up a bit to get across the 72nd Street transverse, or will you reach it at the same time as that stream of cars, forcing you to stop and wait?

All in all, rollerblading in Central Park is a great way to exercise, complete with beautiful views, great places to rest, and the everpresent chance to spot celebrities. But if you’re the kind of person who likes to tune out while you sweat, then it may not be for you; self-preservation requires you to stay on your toes.