Salkantay trek is the most intense, adventurous and worth-while experience I've ever had !!
Day 1 Is beautiful. We walked past two glaciers and even ventured up to a glacial lake which was hard, but breathtaking - definitely worth the extra effort.
Day 2 Is hard! Be prepared for snow!
Day 3 Is easier though, plus we entered the jungle!
Day 4 We continue through the jungle - I counted 32 mosquito bites in just one leg, so for the love of god don't forget good bug spray!!.
Finally, don't forget some ibuprofen because this trek is hard on the knees!. It is definitely physically demanding, but worth it! Highly recommended :) the guides are very supportive and adapt to your individual needs too!.