Good hikers should have no problems to do the trek in 3 days but most prefer 4 days in order to enjoy the scenery and to explore the road-side inca ruins. You follow an old Inca trade route which is either very well graveled or even layed out with rock plated. Only one portion is a little muddy in wet conditions but even an average Joe should have no problem here. The trek can be done with an average to good level of fitness. Don't take it too easy though -t without any physical preparations you will not have much fun with the rather high mountain passes. If you're normally living close to sea-level it is a good idea to stay a couple of days in Cusco in order to get a little bit adjusted to the heights. There is not much time to acclimatize on the trail itself.

Day 1:

Inca Trail

Your day will usually start in Cusco where you meet the rest of your group. The trail head is reached by bus or by train after about 3-5 hours. The starting point can be varied a little - most tours will either start at km 88 or 92 of the railway route from Cusco. Usually you will meet your porters here. If you prefer walking sticks be prepared for a little surprise here: you are REQUIRED to protect the Inca trail by attaching a rubber knob (for a few bucks naturally). From here you cross the Vilcanota river and follow the river (down or up dependent on where you started) for a little while before hiking up a valley to your first camp near the village of Wayllabamba at ~3000m. You are rewarded with excellent vistas of the surrounding mountains here. This first day tends to be quite dry but don't take this as a guidance for the rest of the trail.

Day 2:

Inca Trail

Prepare for a rather strenuous day because you will need to hike beyond the tree line to the first and highest pass of the trail - the "Dead Woman's Pass" (~4200m). Nomen est omen so you will find a couple of ill-prepared hikers here gasping for air. Make sure to take wind-stopper clothing because the area is quite exposed here and the wind-chill factor can be quite high especially after the sweaty way up. It is a quite long way down but you will pass your first may Inca ruins. They are all over the place anyway but near you campsite (~3600m) there're a couple of bigger and restaurated strongholds.

Day 3:

Inca Trail

Today you will have to cross two passes at 4000m and 3700m in a deep, dense and wet cloud rain forest scenery. Regardless how the weather looks like take some good rain gear here. If the weather is fine you will be able to enjoy vast panoramas of the Andes wherever the rain forest opens a little. The camp is a quite crowded place but the vistas are excellent and if you have a little power left you can visit another Inca ruin nearby. Some groups continue to the rather crappy hostal of Wiñay Wayna for the night.

Day 4:

Inca Trail

On the last day you descend about a thousand stone steps before reaching the ruins of Wiñay Wayna - the best ruins on the trail so far located in an awesome setup. The little village is surrounded by several ancient agricultural terraces. Enjoy a coffee or tea in the nearby hostal before starting your final run towards Machu Picchu - the undisputed but very crowed highlight of the trip. The groups who spend the night in Wiñay Wayna may attempt to reach the Sun Gate (Intipunku) at sunrise which is the final pass from where you will have the first vistas of Machu Picchu, an unforgettable view (hopefully without clouds). Another 15min will bring you into the heart of the ruins. From here you can take a bus to the same-named village.

Tip: Better plan a spare day in the village to enjoy the ruins once more on the next day. The chances are very high that the weather isn't all that perfect when you arrive on the trail.