I landed in Colorado yesterday for the weekend. We decided to head out for a 5km trail run.
In most places around Denver you can see the Rocky Mountains, they are a prominent landmark for this region.
I struggled a bit with the altitude, with my heart rate getting up pretty high pretty quickly. With altitude, the hemoglobin in the red blood cells can't bind Oxygen as easily. It takes some time training in altitude before the body adapts, its a tactic elite athletes use - train at altitude to make the body more effective at utilising oxygen, then when competing at sea level the body is much more efficient at replenishing oxygen which helps in energy creation.
This was a cool little trail not far from Parker, with great weather for being outside!