There's no nice way to say this...getting from northern Argentina to Cusco, Peru in about a day & a half was actually pretty miserable. A 24 hour busride + a ridiculously early morning border crossing to catch an early morning flight cannot be understated in terms of discomfort. I would rather roll around in thumbtacks than do this again. I would strongly not recommend trying to do this in under 36 hours. After enduring the aforementioned 24 hour busride from Salta, Argentina to Arica, Chilé, that included traveling at heights of over 5,000 meters (16,400 feet) which sounds all nice & dandy but it actually feels like this guy is sitting on your chest, I then had the pleasure of crossing the border at from Chilé into Perú at 6am Chilean time / 4am Peruvian time. I say pleasure because when you hire a taxi to cross the border you probably don't expect to be sheperded across international borders in a smooth Chevrolet Caprice. Sure the Chevy driver's manual will say this 'little 4-wheel slice of heaven' seats only 5 personas but when you're rolling in the 'Cla$$ic' model you can fit 7 peeps inside. It was glorious. Soon enough I was in Tacna, Peru where I caught my flight to Cusco and was finally at my destination. Whew.
Arriving in Cusco was a relief on many levels as I would have lots of time to relax/catch up on sleep and acclimate to the altitude of 11,400 feet ahead of starting the Incan trail hike 4.5 days later. And DAMN it didn't take long for the altitude to start slapping me around. I did nothing but drink coca tea and sleep for like my first two and half days. And I don't really have a good reason for this but I decided to try my hand at doing a casual little jog near my hotel on my third day...basically it was an uncomfortable combination of 1 part heart attack and 1 part coughing attack from the smog / car fumes. Once again let's add this to the list of things I do not recommend you do.