Not everyone gets altitude sickness , but all people are effected by the lack of oxygen at high altitude . It takes more than a day to adjust to the higher altitude , but if you are in good/very good shape , you should be fine . You'll get out of breath a lot quicker than at home , so watch your heart rate too . It will be working harder to get the oxygen from the lungs to where it's needed . Also don't drink alcohol , or at least drink less of it than you normally do .