I mean, sure, try to acclimate somewhere if you're coming in from sea level, but much of Colorado is at that elevation, and the peaks are above 14,000 feet. Traveling to ski at Telluride is more elevation.
I can say with certainty that it wasn't enough to keep up with our Inca guide or even to tackle the hike with no complaints. While I'm sure it helped considerably to prepare for months ahead of time, I personally feel that there's some other unquantified difference between here and there that makes it just a bit harder. But try it and let me know if it was just a walk in the park. Just don't drink the coca tea the night before you start your hike like I foolishly did.
We also did hyanu piccu, which is absolutely amazing and an additional hike that is like a sprint at the end of a difficult race. It doesn't take long, but at the very least can give you a great carido workout.
Cuzco is at ~11,000 ft, and most people arrive via a short flight from Lima, which is at sea level. So you do gain a bit of altitude in a pretty short amount of time.