This is how modern alpine style climbers reach great heights in short amounts of time without bottled oxygen. The jury is still out on this one. I did use it at 20,000 ft and found the side effects a problem. I wouldn't suggest using it while running a race. I found that Motrin knocked out the altitude headache.
High altitude is more than lack of oxygen.
If it were just that, you could train by stuffing a sock in your mouth. In summary, high elevation endurance events are great challenges to the body and the mind. Acclimatize if you can. If not, run smart, hydrate, pressure breath, and enjoy the scenery. An excellent source of information on altitude is the book, Going Higher, by Charles S. Houston, MD published by little Brown and Company.