Taos Trials: Altitude Lies Stealing Arginine Gains?

By Franklin Everett Shaw

December 27, 2025

Forget the protein shakes and fancy compression gear for a second. If you’re an athlete training in Taos, New Mexico, or any other high-altitude locale, you’re fighting a battle you probably don’t even know about: arginine depletion. This isn’t some fringe theory; it’s a real physiological challenge that can sabotage your performance gains.

Arginine, a conditionally essential amino acid, plays a crucial role in nitric oxide (NO) production. NO is a vasodilator, meaning it widens blood vessels, improving blood flow and oxygen delivery to muscles. At altitude, your body is already struggling to get enough oxygen. Arginine depletion exacerbates this problem, hindering your VO2 max and overall endurance.

So, what’s happening in Taos, specifically? At 6,969 feet, the air is thinner, and your body responds by increasing red blood cell production to compensate for the lower oxygen saturation. This process, while beneficial in the long run, initially puts a strain on your system. Arginine is heavily involved in this adaptation, getting diverted from NO production to support erythropoiesis (red blood cell formation).

Here’s the kicker: many athletes mistakenly focus solely on iron supplementation at altitude, neglecting arginine. Iron is vital for hemoglobin synthesis, but without sufficient arginine, your body can’t efficiently utilize that iron to improve oxygen delivery. It’s like having a high-performance engine with a clogged fuel line.

Let’s get practical. How do you combat altitude-induced arginine depletion and maximize your training in places like Taos? It boils down to a three-pronged approach: dietary optimization, strategic supplementation, and smart acclimatization.

First, dietary arginine. While arginine is found in many foods, getting enough through diet alone at altitude can be challenging. Good sources include:

• Turkey breast: A lean protein source packed with arginine.
• Pumpkin seeds: A surprisingly rich source, and easy to snack on.
• Soybeans: Versatile and can be incorporated into various meals.
• Nuts (walnuts, almonds): Healthy fats and arginine in one package.

However, bioavailability matters. The arginine in food might not be as readily absorbed and utilized as supplemental arginine. This is where strategic supplementation comes in.

Second, arginine supplementation. This is where things get interesting. L-arginine is the most common form, but it has relatively poor bioavailability. A better option is L-citrulline. L-citrulline is a precursor to L-arginine, meaning your body converts it into arginine. This conversion process bypasses some of the metabolic bottlenecks that limit L-arginine’s effectiveness.

Dosage is crucial. Start with 3-6 grams of L-citrulline per day, split into two doses. Take one dose about an hour before training and another before bed. Monitor your body’s response and adjust accordingly. Some athletes experience gastrointestinal distress with higher doses, so start low and go slow.

A common mistake is to take arginine supplements only on training days. Arginine depletion is a chronic issue at altitude, so consistent supplementation is key. Think of it as a daily vitamin, not just a pre-workout boost.

Third, acclimatization. This is the most overlooked aspect. Don’t jump into intense training immediately upon arriving in Taos. Give your body time to adjust. A gradual increase in training intensity over 1-2 weeks is crucial.

Here’s a specific acclimatization protocol:

• Days 1-3: Light activity only. Hiking at a moderate pace, easy cycling, or gentle yoga. Focus on hydration and nutrition.
• Days 4-7: Introduce moderate-intensity workouts. Short runs, interval training with longer recovery periods, or strength training with lighter weights.
• Days 8+: Gradually increase training volume and intensity. Monitor your heart rate and perceived exertion closely.

A pitfall to avoid is overtraining during the initial acclimatization period. Your body is already under stress from the altitude, so pushing too hard too soon can lead to fatigue, injury, and a suppressed immune system. Listen to your body and prioritize recovery.

Now, let’s talk about VO2 max. This is the gold standard for measuring aerobic fitness. Altitude training can improve VO2 max, but only if you mitigate the negative effects of altitude sickness, including arginine depletion.

Here’s how arginine supplementation can directly impact VO2 max:

• Improved blood flow: Increased NO production leads to better oxygen delivery to working muscles.
• Enhanced mitochondrial function: Arginine plays a role in mitochondrial biogenesis, the process of creating new mitochondria, the powerhouses of your cells.
• Reduced muscle fatigue: Better oxygen delivery and mitochondrial function translate to less fatigue during intense exercise.

A study published in the Journal of Applied Physiology showed that L-citrulline supplementation improved exercise performance and reduced muscle fatigue in cyclists at sea level. While this study wasn’t conducted at altitude, the underlying mechanisms are the same. By improving blood flow and mitochondrial function, arginine supplementation can help you push harder and longer, ultimately leading to a higher VO2 max.

But remember, arginine supplementation is not a magic bullet. It’s one piece of the puzzle. You also need to focus on proper hydration, nutrition, sleep, and stress management.

Here’s a real-world example: a marathon runner training in Taos for the Leadville 100. This runner initially struggled with altitude sickness and plateaued in their training. After incorporating L-citrulline supplementation (6 grams per day) and following a gradual acclimatization protocol, they saw a significant improvement in their endurance and were able to complete the Leadville 100.

The key takeaway is this: altitude training can be incredibly beneficial, but it also presents unique challenges. Arginine depletion is one of those challenges that is often overlooked. By understanding the science behind it and implementing a strategic approach to diet, supplementation, and acclimatization, you can unlock your full athletic potential in high-altitude environments like Taos, New Mexico, and finally achieve that VO2 max you’ve been striving for. Don’t just train harder; train smarter.