Many of you have summer races planned for someplace other than the desert. Smart move if you're looking to avoid the heat. But racing up north can mean racing at altitude, and that can make for a tough race if you're not prepared.

Experts say it takes about two weeks to get fully acclimated to an elevation above 5,000 feet - and keep in mind that Flagstaff, home to July's popular Mountain Man Triathlon, is at 7,000 feet. You're likely to feel the worst effects of altitude day three to 10, so plan to either arrive the day before your event or full two weeks prior.

According to an article in Running & Fit News, race performance starts to be affected at about 3,500 feet. Racers not acclimated to the elevation will lose a net total of 6 percent of their performance when racing at 6,500 feet, or about 2 minutes for a 10K race, according to the article's authors.

Racing at elevation increases the stress on your body. Experts say this is particularly true with lactate tolerance and anaerobic endurance. This means you need to arrive at your race in top condition and well rested - doing so will allow you the best opportunity to perform well under the extreme conditions.