Best Diet for High Altitude
Gain the Skiers Edge by Eating Right in the Mountains
Steve Parcell, ND
NatureMed, LLC/ Boulder, CO
The aim of this article is to discuss how physical activities at high altitude can potentially affect nutritional requirements. Medium altitude is defined as (1500-2500m) at this altitude oxygen saturation remains above 90% but altitude illness is possible. At high altitude (2500-5300m) oxygen saturation falls below 90%, altitude illness is common and acclimatization is necessary. As a point of reference oxygen saturation in Boulder, Colorado (5400 ft) is approximately 94%. Alpine skiing in the North American and Canadian Rockies commonly occurs at or above 3000 meters (9842 ft). Skiers who live in ski country are subject to decreased performance but those that fly in from sea level suffer even more.
It is easy to become dehydrated in high-altitude environments. Dehydration increases the risk of frost bite and worsens the fatigue, impaired judgment and apathy of hypoxia. The body's requirement for fluids is very high at altitude; often exceeding 4 liters of water per day. Altitude increases water losses from the lungs due to the cold, dry air. There is also increased urinary loss of water because altitude and cold have diuretic affect. Sweating adds to the water loss. Drink a minimum of 1 quart of water every three hours. I recommend putting a pinch of salt in plain water of using a sports drink. Make sure the sports drink has sodium listed on the label. You can also make your own sports drink by adding 1/2 tsp sea salt, three tablespoons of sugar or honey and a ¼ cup of fresh lemon or orange juice to one quart of water
Carbohydrate is the preferred energy source at altitude. Carbohydrate replaces depleted muscle glycogen, prevents muscle from being used as energy, and requires less oxygen for metabolism. . Glycogen is a form of sugar stored in muscles. A high-carbohydrate diet can reduce the onset and severity of AMS and improve physical performance. A low-carbohydrate diet can result in low blood sugar. Although high-fat foods are energy dense, fat is not tolerated well at altitude and can worsen the symptoms of AMS. Fat requires more oxygen for metabolism than carbohydrate. If high-fat foods are tolerated and desired, they should be eaten with carbohydrate foods.
When first arriving at high altitude your body uses more blood sugar as a fuel source during rest and during exercise. Muscle glycogen is not decreased but the reliance on fat for energy declines. In other words, fatigue and low blood sugar levels will occur more quickly at the same intensity of activity at altitude compared to sea level if increased carbohydrate intake does not occur.
In addition to reducing fatigue and preventing low blood sugar levels it has been shown that a diet high in carbohydrate can prevent symptoms of acute mountain sickness or (AMS). Studies have shown that a high carbohydrate intake can reduce the effects of altitude by 1000 ft – 2000 ft at a height of 13,000 ft and 17,000 respectively. This is most likely due to the fact that carbohydrate requires 8-10% less oxygen for metabolism, compared to fat and protein. The ideal fuel at high altitude is carbohydrate.
Convenient food sources of carbohydrate for skiing:
• Energy bars!
• Oatmeal with raisins, flax oil or butter and nuts for breakfast
• Whole wheat pancakes or waffles (skip the fake maple syrup)
• Low fat sandwiches
• Pasta and rice
• Low fat soup with bread (no butter)
• Sports drink (with sodium on the label)ITTLE peanut butter is OK)
Protein, fat and carbohydrates are all sources of calories. Above all, it’s important not to go into what I call “calorie debt.” Calorie needs go way up when skiing and especially at higher altitudes. As an example, if you normally eat 3000 calories a day you may need up to 6000 calories on a hard day skiing. Even though carbs are the preferred fuel at altitude it’s always better to eat the wrong food than no food at all.
Best bets: whole wheat pancakes, or oatmeal (with nuts, butter and raisins) for breakfast. Sports drinks or low fat energy bars can be consumed while skiing. Avoid a big lunch. Good lunch options are soup with bread or a low fat sandwich. Skip the sour cream and cheese and other fat rich foods like pizza and French fries if you are interested in top performance after lunch. My research also shows that alcohol at lunch increases ski related injuries.
Do You Need Extra Vitamins?
There is no evidence that extra vitamins are needed above usual needs. We do recommend that skiers take a daily multivitamin on a regular basis, however. If you want to see if you may have extra requirements for vitamins and minerals ask us about a special test that may be covered by your insurance.
Free radical damage to cells increases with altitude because anaerobic metabolism predominates and ultraviolet exposure increases. Free radical damage is a main cause of aging. Humans make their own natural protective antioxidants but these levels can go down when exercising intensely at high altitude unless the individual is “trained.” Trained athletes are able to counteract the damaging effects of free radicals because they produce more natural antioxidants.
Vitamin E supplementation at high altitude has shown positive effects in mountain climbers working at 1600 ft. Tests showed lower levels of oxidative damage as well as a higher exercise performance capacity. Other studies show no effect. A more recent study published in the August 2006 edition of “Medicine and Science in Sports and Exercise” demonstrated that prior treatment with antioxidants could improve ventilatory threshold. This is the point at which your breathing rate really goes up or what skiers sometimes call “busting a lung”.
Dos and Don’ts at High Altitude:
DO avoid alcohol for the first two days if flying in from sea level.
DO avoid excessive caffeine consumption.
DO eat a high, complex-carbohydrate diet.
DO bring energy bars and sports drink with you
DO consider a personal hydration device
DO drink 4 to 6 quarts of non-caffeinated
beverages per day & monitor color/volume
of urine for dehydration. Urine should be light yellow.
DO consider an antioxidant supplement
DO avoid high-fat, foods.
DON'T skip meals.
DON'T fill up on high-fat foods.
DON'T restrict water intake in order to avoid having to urinate.
DON’T drink too much alcohol on your first night in the mountains.
Naturopathic physicians and co-founders of NatureMed, Steve Parcell, ND and Kelly Parcell, ND practice in Boulder, CO. They are both competitive athletes and avid skiers. NatureMed offers athletic performance improvement programs for athletes of any age.. Clients include top athletes from around the world. For more information go to www.naturemedclinic.com or call 303.884.7557.