High-altitude training applies unique stress to the body. If you plan to spend time exercising at elevations above 5,000 feet (about 1,500 meters), you’ll need to take special precautions.
Many elite endurance athletes spend some portion of their training calendar living at high altitude, in places such as Boulder, Colorado or Flagstaff, Arizona. Because the concentration of oxygen in the air is lower compared to sea level, the athlete’s body will undergo certain hormonal and cardiovascular changes that help transport oxygen more efficiently to the muscles. When the athlete returns to sea level, those adaptations are maintained for a few days to a few weeks, boosting athletic performance.
Popular endurance events can occur at higher altitudes as well. The Western States 100, for instance, exceeds 8,700 feet (2,650 meters) in some places.
Regardless of whether you are training or racing, if you plan to exercise at higher altitudes—elevation that exceeds 5,000 feet (1,500 meters)—you will need to take a different approach to hydration.
Hydration at higher altitudes
In addition to lower oxygen concentration, the air at higher altitudes is less humid, which allows sweat to evaporate from the skin more quickly. Very dry air can trick a person into thinking he or she is not sweating much, even if water loss occurs at a high rate. Athletes lose more water through breathing at higher altitudes for the same reason.
Combined, these effects increase the amount of water a person will need to consume to stay hydrated, and some estimates advise athletes to drink an extra 1 to 1.5 liters of water daily.
Electrolytes also play a role in hydration. When we sweat, we lose salts, including sodium, potassium, calcium and magnesium. As the Wilderness Medicine Society Practice warns, if high-altitude athletes do not take precautions to replace lost electrolytes—and instead rely on water alone to stay hydrated—they run the risk of a dangerous condition called hyponatremia. This condition, caused by low levels of sodium in the blood, can lead to headaches, nausea, disorientation, fatigue and, in extreme cases, loss of consciousness or death.
Therefore, as water consumption goes up to meet the demands of higher-altitude training, electrolyte consumption should also rise. The following chart may help when planning your routine. Please remember each athlete is different, and you should therefore adapt this to fit your unique needs.
| Elevation | Additional Water | Additional Electrolytes |
| Sea Level – 5,000 feet (1500 meters) | None | None; adhere to normal recommendations |
| Altitude: 5,000 – 8,000 feet (1,500 meters – 2,400 meters) | 0.5 liters | 250 mg of sodium (1 SaltStick Capsule) per hour, during exercise |
| High altitude: 8,000 – 12,000 feet (2,400 – 3,650 meters) | 1 to 1.5 liters | 250 mg of sodium (1 SaltStick Capsule) per hour, during exercise |
| Very high altitude: 12,000 – 18,000 feet (3,650 – 5,500 meters) | 2 to 2.5 liters | 500 mg of sodium (2x SaltStick Capsules) per hour, during exercise |
| Extremely high altitude: 18,000+ feet (5,500+ meters) | In extreme situations, it’s best to work with an expert to determine your unique needs. | |
Electrolyte supplements can help reduce the chance of hyponatremia, and many athletes around the world have found success with SaltStick products, which contain the full spectrum of electrolytes lost in sweat, in a form the body can easily absorb. One SaltStick Capsule, for instance, contains 215 mg of sodium, 63 mg of potassium, 22 mg of calcium and 11 mg of magnesium, along with 100 IU of Vitamin D to help the body absorb and utilize calcium.
You can view the complete nutritional breakdown of all our products here.
Adapting to high altitudes
As we ascend into higher altitudes, the amount of oxygen in the air decreases, meaning that we take in lower amounts of oxygen with each breath. (Notably, oxygen remains 21% of the air by volume, but each breath simply contains fewer molecules of all gases that comprise air). Oxygen is crucial for our cells to function; without it, the human brain will die after just six minutes. As a result, at elevations beyond 5,000 feet (1,500 meters) the maximum output a person can deliver decreases by 3% for every 1,000 feet (300 meters).
This lack of oxygen also results in characteristic altitude sickness symptoms: headache, nausea, shortness of breath and the inability to “push yourself” physically. Most people can adapt to the lower oxygen levels after a few days, but it is important to give the body time to make the necessary physical changes to support training at high altitudes before performing an intense workout.
The Institute for Altitude Medicine recommends that aerobic events at elevations over 5,000 feet require 10-20 days of acclimatization in advance. Moreover, athletes participating in events over 12,000 feet must go through acclimatization at an intermediate altitude prior to performance. During these acclimatization phases, the athlete can experiment with changes to his or her hydration routine to prepare for race day.
Proper hydration, low alcohol consumption and slow ascent can help reduce the likelihood of altitude sickness. However, if an athlete suffers from altitude sickness, there is no “cure” except for transitioning to a lower altitude to slow the adaptation process down.
Conclusion
If you are headed to a high-altitude location to train or race, be sure you do not forget about the unique hydration needs you will face. With proper planning, you will be ready to perform safely and at your best.
Disclaimer: Contact your physician before starting any exercise program or if you are taking any medication. Individuals with high blood pressure should also consult their physician prior to taking an electrolyte supplement. Overdose of electrolytes is possible, with symptoms such as vomiting and feeling ill, and care should be taken not to overdose on any electrolyte supplement.