Start with Food First
Before you spend a dollar on supplements, make sure you have covered the basics. That means eating enough, eating consistently, and choosing nutrient-dense foods to meet your macro- and micronutrient needs. Most nutrition-related performance gains come from a food-first approach—not from a powder or a capsule.
Supplements are tools to fill specific gaps or provide a performance edge when needed. They are not replacements for real food. If your diet is poor, no supplement will fix it. If your diet is solid, the right supplement used at the right time can provide a meaningful benefit. The order matters.
Four Questions to Ask Before Taking Any Supplement
The supplement market is overwhelming. Thousands of products claim to boost energy, improve recovery, support joints, or supercharge endurance. Before you reach for any of them, run it through these four questions.
1. Does it do what it claims—and do you actually need it? Many athletes reach for supplements promising more energy or faster recovery without first addressing root causes like poor sleep, underfueling, or insufficient training structure. If the problem is that you are not eating enough, the solution is food, not a pill.
2. Is it safe? Safety includes not only the listed ingredients but also the potential presence of contaminants or banned substances. “Natural” does not mean safe. Some herbs interact with medications or foods, causing dangerous side effects.
3. Is it third-party tested? Because the supplement industry is poorly regulated, independent testing is essential. More on this below.
4. Does it fit your budget? If a supplement costs more than your monthly food budget, question whether it is the best path forward. The fundamentals—training, sleep, hydration, and whole food nutrition—will always deliver more per dollar than any supplement.
Why Third-Party Testing Matters
Supplements are not regulated by the FDA in the same way as food or pharmaceuticals. Without independent testing, what is on the label may not match what is in the bottle. Worse, some products contain banned substances, heavy metals like lead or cadmium, or undisclosed ingredients. A protein powder could literally contain anything from sawdust to stimulants.
Third-party testing does not guarantee that a supplement works. It guarantees that what is on the label is what is in the bottle—and nothing else. That distinction matters.
Look for these certifications:
NSF Certified for Sport. The most widely recognized certification for athletes. NSF maintains a searchable database of verified products.
Informed Sport. Another rigorous third-party program with a searchable product database.
Avoid supplements that list “proprietary blends.” This is a red flag. Proprietary blends obscure ingredient amounts and can hide low-quality or risky additives. If a company will not tell you exactly what is in their product and in what quantity, do not put it in your body.
Two Categories of Supplements
Nutritional supplements address micronutrient deficiencies—things like vitamin D, iron, or magnesium. These should be based on confirmed need, ideally through bloodwork and a conversation with a healthcare provider. Do not guess. For example, iron deficiency is common in endurance athletes, especially women, but supplementing iron without lab confirmation is dangerous because excess iron can cause serious harm. For more on this, see our article on nutrition for the female uphill athlete.
Performance supplements (ergogenic aids) are used to enhance performance directly—protein powder, creatine, caffeine, and similar products. Some supplements, like protein powder, can serve both purposes: filling a dietary gap and supporting performance.
In most cases, a multivitamin is unnecessary. It is more effective to supplement specific nutrients based on your individual needs rather than taking a broad-spectrum product that gives you a little of everything and enough of nothing.
Evidence-Based Supplements for Mountain and Endurance Athletes
Protein Powder
A practical tool for athletes who struggle to meet their protein needs through food alone, especially post-workout or during expeditions when whole food options are limited. Whey protein is ideal for most athletes—it is well-absorbed and has a strong amino acid profile. For dairy-free diets, plant-based blends combining pea and brown rice protein, or soy protein, are excellent alternatives.
When shopping: Choose third-party tested brands certified by NSF for Sport or Informed Sport. Whey protein is available as isolate (lower in lactose, more protein-dense) or concentrate (closer to whole milk, slightly less processed). Whey in particular is prone to contamination with heavy metals unless independently tested.
Creatine Monohydrate
One of the most extensively researched supplements in sports science. Creatine helps regenerate ATP—the molecule that powers muscle contraction—and supports strength, power, and muscle recovery. While commonly associated with gym-based strength training, mountain athletes including climbers, skiers, and runners can benefit from creatine’s effects on repeated high-effort output and recovery between efforts.
Dosing: 3 to 5 grams per day. No loading phase is necessary. Expect a minor increase in water weight after the first 3 to 4 weeks. When shopping: Look specifically for creatine monohydrate, which is the most studied and effective form. Other forms (HCL, buffered, etc.) lack the same evidence base.
Caffeine
More than a morning ritual—caffeine is a well-documented performance enhancer that improves focus, alertness, and endurance during long workouts and races. It works by reducing perceived effort, allowing you to sustain higher output for longer.
Use mindfully. Stay below approximately 400 milligrams per day. Be aware of its effects on hydration and sleep, particularly at altitude where both are already compromised. Timing matters—caffeine peaks in the bloodstream about 45 to 60 minutes after ingestion.
Magnesium
Relevant for sleep quality and muscle recovery, both of which are critical during heavy training blocks and at altitude. Many endurance athletes are mildly deficient without knowing it.
When shopping: Choose glycinate or bisglycinate forms for sleep and recovery support. Avoid citrate if you do not want a laxative effect. As with all nutritional supplements, confirm a need through bloodwork or dietary assessment before supplementing.
Collagen
Popular for joint health, but the evidence for performance or injury prevention is mixed. Collagen is well-supported for hair, skin, and nail health, less so for connective tissue repair in athletes. If you choose to take it, ensure you are also eating enough total protein and pairing the collagen with vitamin C, which supports collagen synthesis in the body.
Greens Powders
Not a replacement for fruits and vegetables. However, greens powders can be genuinely helpful when fresh produce is unavailable—during expeditions, extended travel, or remote training camps. When at home, prioritize a diet rich in actual fruits and vegetables. When shopping: Choose only third-party tested brands, as greens powders are frequently contaminated with heavy metals.
Bicarbonate
Can buffer lactic acid and improve performance in short, high-intensity efforts. However, the risk of gastrointestinal distress is high and should not be underestimated. Experiment with low doses (0.1 to 0.2 grams per kilogram of body weight) in training first. Build up to 0.3 grams per kilogram only if tolerated. This is a supplement for specific competitive situations, not daily use.
Drug and Food Interactions
Some supplements interact with medications or with certain foods in ways that can be dangerous. A well-known example is St. John’s Wort, an herbal supplement sometimes used for anxiety, which can cause dangerously elevated blood pressure when combined with fermented foods.
If you are taking any medication, consult a pharmacist before adding a supplement. This is not optional—it is a safety requirement. Even common supplements like magnesium or iron can interact with prescription drugs in ways that reduce their effectiveness or cause adverse effects.
The Bottom Line
Smart supplementation starts with smart questions. If you do not have a clear, evidence-based reason to take a supplement—and a clean, certified product to use—it is usually better to skip it.
Build your base with whole foods, good sleep, and consistent training. Then, if a supplement fills a specific, confirmed need, use it intentionally. That is the order. That is the approach that works.
For personalized nutrition guidance tailored to endurance and mountain athletes, explore our nutrition coaching or schedule a consultation with our registered dietitian.