I just finished the 4 day Machu Picchu trail hike and would recommend it to anyone who is looking for an outdoor adventure. The benefit of doing the full four days is that you get a lot of Incan history by viewing several ancient ruins along the trail. The journey builds as you view the ruins and hike over several mountain passes. By the time you reach the Sun Gate to Machu Picchu you have experienced the same journey as the ancient Incan's may have also experienced making the final Machu Picchu tour all that more enjoyable.
For hikers used to 4 day high altitude hikes (over 14,000 ft) this hike won't be so difficult but for those who are new to such a journey the tour companies that run the hike make it much more manageable. I'm used to 4 day hikes in a U.S. National Forest or Park where I am responsible for all food, water and shelter however the tour companies who lead the hikes make the journey much easier by providing and carrying essential items such as tents, food, cooking gear, sleeping bags and sleeping pads among other items.
I am not used to waking up with a knock at the tent door by someone offering a hot cup of tea in the morning as if I want tea while camping I usually need to make it myself after a water run to the river but that's just a small example of what you can expect on the hike. Our tour company had a nice table setup at each breakfast, lunch and dinner with two to three course meals prepared by a dedicated chef who hiked with us.
Several of the campsites are built on terraces which provide breathtaking views of the valley's below and surrounding mountains. We were fortunate to have clear weather in the evenings, making the stars clearly visible. We were able to clearly see the Milky Way, Southern Cross and Big Dipper among other constellations each evening.
It is also possible to take a train and bus up to Machu Picchu within one day but after doing the four day hike I feel like something would be missing as the journey makes the final reward of seeing Machu Picchu all that much better.
I went with the tour company "Incatrekkers" which is a small locally owned and operated tour company. I can't say enough about the service and attention to detail they provided. The guide was very friendly and knowledgeable. The equipment was top notch. The food was outstanding. If you're looking for a tour company please take a look at their website: http://www.incatrekkers.com.