The trip ended up surpassing all my expectations. We had 4 days of hiking and 3 days of overnight camping arrange with the Llama Path company in Peru, which is a recognized environmentally and socially responsible tour group which arranges hiking trips along the Inca Trail. We hiked the most famous section of the Inca Trail, which is a 27 mile stretch which is limited to 200 tourists per day by the Peruvian goverment. (Reserve your spot WAY in advance!) The support crew is provided by porters - 1.5 porters per hiker to carry tents, food, and fuel.
The most challenging aspect of the tour by far was the altitude. The hike begins near the town of Cusco, Peru at a lofty 11,000+ feet above sea level. According to the tour guide, at this altitude, you are only receiving 65% of the O2 that you would receive at sea level. Also, the pressure of oxygen as well as the hemoglobin O2 carrying capacity are both decreased. As soon as we landed in Cusco, I found myself short of breath. This worsened upon laying down, to the point that I couldn't sleep for more than 10 minutes at a time, because I became so short of breath that my body would wake itself up with a jolt of adrenaline. I also developed chronic headaches in the first two days that made hard exertions very difficult. In speaking to the others in our tour group, pretty much everyone had experienced similar or worse symptoms.
The hike itself was grand on an epic scale, and too full of incredible experiences to go into at depth. I was one of the few hikers in our group of 11 to not hire an extra porter to lighten my load, so I was carrying a 35lb pack which grew to 42 lbs by the second day since I was helping my fiance lighten her load. Most people carried about 10-15 lbs of weight.
All 4 days were challenging, but day two of the hike was exceptionally challenging. 9 hours of climbing, 5 of which were a grueling uphill, and 4 of which were a super-steep, rock-lined relentless downhill. This involved 2000 meters of climbing, and a 1200 meter drop, all across very tricky boulder footing.
To put this in perspective, the Empire State Building in New York City is 320 meters tall. Strap on a 42 lb backpack, and rearrange the stairs of the Empire State Building so that they are all taller than 6 inches, and often 12-18 inches tall, and very irregular in size and shape. Then start climbing. Repeat SEVEN times. As well, you start at 11,000 feet of altitude, so you're already out of breath even just standing around before you start. And when you finally get to the top, you have to come back down the an equally steep and equally treacherous descent for 4 more hours. Make no mistake about it - this hike is HARD.
Setting sun on the mountains at altitude
After the 2nd day, I was completely, utterly toasted, and barely made it through dinner without passing out. I recall at noon, being pale as a ghost, and having to lie down after barely eating any lunch because the combination of fatigue, headaches from altitude sickness, and sun exposure left me barely able to stand - and I had 2 more hours of crushing uphill hiking and 2 hours of a steep descent that same afternoon! I still am not sure how I made it up that afternoon, but I do recall going into "survival mode" and just focusing on putting one foot in front of the other no matter how much my body wanted to give up. I didn't see much at all in those hours - and just kept the relentless slow effort going, as I would in the final miles of a marathon. Interestingly, once I began to suffer, I felt more confident in my ability to succeed in finishing, as I have become very familiar with the perceptions of suffering during workouts, and I can fairly accurately gauge what reserves I have left. While resting, I cannot gauge this as accurately, and started to fall prey to various fears in my head.

Inca doorway
As I write this, my legs are still recovering' from the beating they took on the trail. I had honestly expected this tour to be "moderately hard, as it is marketed to non-athletic tourists, but with the addition of a heavy pack, it definitely entered "extremely hard" territory. I lost a few pounds after this trek, mostly because my appetite was eliminated due to the altitude sickness, so I was eating way fewer calories than I was burning. Remarkably, all 11 of the tourists made it through the entire hike, and in fact, the tour guide said that 95%+ of people complete the trek as planned. So I guess I'm not as tough as I thought I was! To my credit though, even the porters were impressed with how much weight I carried. On the 3rd day, which had a monstrous descent, I ran down most of the rocky trail, finishing just behind the porters, who hadn't even started to set up for the group's arrival. It took them a few moments to realize that yes, a gringo with a pack was keeping pace, and when they lifted my pack, they immediately ran to get a lifting scale because they didn't believe that I was carrying such a heavy sack! Despite our language difference (most of the porters spoke only the native Quechua language), their grunts and claps of approval at my fast finish was a priceless reward for my hard day's workout.

The "Red Army" - our porters
Special mention gets made of the porters on this trip. They now can legally carry only 25 kilos, or about 54 lbs of weight, but they move FAST. Our porters formed a big line called the "Red Army", and literally ran most of the trail, arriving far in advance of us gringo hikers, so that they could set up tents and meals before we even arrived at the campsite. I could just barely keep up with them on the climbs with my 42 lb pack with a maximal effort, and on the treacherous downhills, I was unable to run as fast as they did without expecting to fall and break something important. These porters are all small males, age 19-45, weighing less than 140 lbs each, and probably closer to 120lbs each. Our company was known for providing adequate equipment to porters, but I saw porters from other companies running at equal speed with sandals made of tires and two straps, with no hiking poles and subpar backpacks. These porters also have at most one change of clothes, and for the most part, slept outside in 28-35F temps at night without tent cover. I have the utmost respect for these men, who routinely put forth these ferocious efforts without complaint, and for minimal pay.

This is one of the "nice and easy" downhill sections
I'm now back in California, enjoying my full breathing and the amenities of a 1st world civilization with a newfound appreciation. I'm also looking forward to use my improved legs - after the beating I took on this hike, I will definitely be stronger on the run and the bike this week, which is a first for me, as I usually end up regressing substantially in performance on any vacation I take. I will leave the history and stories of the Inca sites and trails to Macchu Picchu to you to research and read about, but suffice to say that as spectacular as these pictures are, they barely do justice to the magnificence and grandeur of the Inca civilization that created these monuments nealy 500 years ago. The combination of an epic hike along the original stone path laid by the Inca civilization left me with countless inspired memories and a new appreciation for a historical culture different from our own.
Enjoying the view after a hard climb