Training at High Altitudes can turn you in to a High Altitude Dude. I just got back from Denver Colorado and trained both at 5280ft and sea level and I can tell you, there is a BIG difference. The positive affects of training at high altitude occurs at elevations above 1500m or 5000ft. Training at this elevation can increase red blood cell count and improve cardio vascular capacity once you return to sea level. I experienced this phenomenon first hand and want to share my thoughts and experiences with you.