Performing at higher elevations (like in North Lake Tahoe, California, where the Spartan World Championships are held) can present a formidable obstacle for athletes: adjusting to high altitude. Unfortunately, if you don’t live in or train at high altitude, you will be at a disadvantage compared to athletes who do. However, I've got a high altitude nutrition strategy you can use to help optimize your efforts.

How Does Nutrition Factor In?

The right high altitude nutrition can maximize blood volume, which according to one scientific review, can, in turn, can help with heat dissipation and result in lower heart rates during exercise. Increased blood volume can also give the body the best possible platform even when hypoxia is a risk. Because blood volume is related to iron, your high altitude nutrition plan must include this crucial mineral.

High Altitude Nutrition to Optimize Blood Volume

You train for race day with weeks of running, high-intensity interval training, and strength work. Why not maximize your high altitude nutrition as well? You can do this by eating enough of the right iron-rich foods to ensure adequate blood volume for race day.

Iron Basics in High Altitude Nutrition

Iron, found in the body’s red blood cells, aids in blood production. It also helps the red blood cells deliver oxygen to working tissue and plays a role in energy metabolism. Iron is a vital component of your high altitude nutrition strategy.

Inadequate iron in the body can result in:

• Decreased blood flow
• Less oxygen delivery to muscles
• Decreased performance
• Feelings of fatigue on exertion and reduced muscle power

Spartans have demanding training schedules of long duration, high intensity, large workload—and, hopefully, a proper nutrition plan to support them.

Dilutional Pseudoanemia – AKA Sports Anemia or Athletic Anemia

When an athlete begins an intensive exercise program, blood volume and red blood cell count both increase. However, the blood volume increases faster than the red blood cell count, so that initially,  the red blood cell concentration is lowered, and the athlete appears to have anemia which can be caused by iron deficiency. Over time, the body adapts and the concentration returns to normal.

Foot-Strike Anemia

Foot-strike anemia is caused by capillaries in the foot breaking as we get in our demanding runs. The red blood cell breakdown caused by this bruising occurs faster than the body can produce new blood cells, producing anemia.

Restrictive Diets

Only a small percentage of iron from food is absorbed, so the recommended range is set high. If you are restricting your overall food intake, you may have an increased risk of not getting enough iron. Coffee or tea drinker? You may be absorbing even less. More on that later.

Unbalanced Diets

Focusing on iron already? What about magnesium, zinc, folate, and B12? These vitamins and minerals also help the body produce red blood cells and help iron do its job.

For the Ladies

If your menstrual cycle overlaps a race, you’ve got yet another obstacle to overcome. Blood loss through menstruation affects overall blood volume. This is another reason for women to focus on high altitude nutrition.

Your High Altitude Nutrition Strategy

Enough on cause and effect. Let’s talk about how you can put together a plan to maximize your iron levels and your performance at high altitudes.

1. Know What You Need

Here is how much iron you need to ingest, according to your sex (source: National Institute of Health):

• Men: 16.3–18.2 mg/day
• Women: 12.6–13.5 mg/day

2. Know the Best Sources

You likely know that red meats and leafy greens contain iron, but don’t forget dates, raisins, beans, tofu, molasses, pork loin, shrimp, and fortified cereals, as well as the following are also good sources of iron for your high altitude nutrition plan:

• Oysters
• Beef liver
• Bison meat
• Beef
• Cashews
• Chickpeas
• Chicken
• Tuna
• Eggs

3. Foods that Inhibit Iron Absorption

Coffee addict? Tea drinker? Components of these drinks can inhibit iron absorption. There’s no need to give them up; just try to separate food intake from coffee or tea by at least an hour.

4. Know Your Iron Levels

Odds are you wear a TomTom or other heart rate monitor, you look at food labels, and you log your miles (mentally or literally) every week. You’ve aced that part of your training; now increase your high altitude nutrition acumen and learn your iron levels.  There are multiple tests available from your doctor to assess your current status. Ask your doctor to check these stats:

• Hemoglobin is the iron-containing, oxygen-carrying protein in red blood cells. Normal values: men: 13.5–17.5 g/dl; women: 12.0–15.5 g/dl.
• Hematocrit is the proportion of whole blood that is composed of red blood cells; often referred to as the number of red blood cells per unit of blood. Normal values: men: 42%–52%; women: 36%–48%.
• Ferritin is an iron storage protein found in the liver, spleen, and bone marrow. Only a small amount is in the blood. This test will indicate the amount of stored iron. The lower the ferritin level, even within the “normal” range, the more likely it is you are iron deficient. Normal values: men: 20–300 ng/ml; women: 20–120 ng/ml.

I recommend that you check these levels at least twice a year: midway through your off-season and midway through race season (or three months before your focused event). It can take about three months to improve your overall status, so starting early will make a difference.

5. Evaluate Yourself, Then Make a High Altitude Nutrition Plan

Now is the time to pay attention to what you’re eating. If you’re already monitoring, it’s time to step it up. For four to seven days, track your intake. How many of the above iron-rich foods do you eat daily? And how much? Using online nutrition trackers such as MyFitnessPal can help you track your daily intake.

Related: 4 Ways To Race Faster At Altitude

Whether you’re getting ready to tackle a new level of elevation at the Spartan Race World Championship, or trying to decrease daily training fatigue, the answer (once again) may lie in your choice of food. Food is not complicated, but following an effective high altitude nutrition regimen will take knowledge, commitment, and discipline. For Spartans, food provides energy and nutrients that support an active, healthy life—even at high altitudes. Spartan Race exists to tear millions of people off the couch and teach them that anything is possible with hard work and perseverance.