In general if you take regular exercise and spend a few days in Cusco acclimatizing to the altitude you shouldn’t have any problem. We recommend that on arrival you do not exert yourself. Ensure you drink plenty of water and keep hydrated. Most hotels offer Coca-tea which is very good to combat altitude sickness. A slight headache is common on arrival, nausea is less common. Most altitude affects dissapate after a day, but if you do feel very ill then its best to consult a doctor.
We offer the Cusco City Tour which you can book whilst you acclimatize.