The moment coach JC opened the training plan, YOUNGER founder Verna realized this was not a race you simply sign up for and turn up to. Ten weeks — not long, not short — two and a half months. She brought in JC to build a periodized plan, then added a movement coach to adjust her running form. Over the course of her preparation she had blood drawn three times, wore a continuous glucose monitor twice, and went up to Cingjing and Hehuanshan twice for altitude simulation.
The travel itinerary had its own logic: first to Chengdu at low elevation, then up the following day to a mountain town at 2,400 meters to sleep and adapt, and only then into Shangri-La at 3,400 to 3,900 meters. Each stage deliberately built in a time gap, purely to give the body a chance to start compensating. As she puts it: "I had never followed a periodized plan before." This time she decided to hand herself over to a system rather than grinding through on willpower.
The real challenge of high-altitude race prep is not willpower
Many people assume preparing for a high-altitude trail race comes down to fitness and willpower — train enough, train hard enough, and you will get through altitude sickness. From a functional medicine perspective, though, the way the body handles the stress of altitude has never been about pushing through. It is about whether you gave it enough time to compensate. This episode breaks down five preparation factors that are easy to overlook yet decide the outcome — from the time window for altitude adaptation and the immediacy of glucose monitoring to medication testing, training load management and blood marker tracking. Not one of them can be skipped by simply trying harder.
Gradual altitude adaptation: red blood cell production takes time
Altitude adaptation takes time — erythropoietin (EPO) only begins driving compensatory red blood cell production after at least 72 hours, raising the body's oxygen-carrying capacity. The gradual ascent from Chengdu to the mountain town and on to Shangri-La exists precisely to give the body a chance to start that process, rather than going straight to the summit, skipping the critical window and exposing yourself to a low-oxygen environment before you are ready. It is also why many mountain guides insist on the principle that your rate of ascent must not outpace your body's rate of compensation — getting there fast does not mean you are ready, and it may expose the body to maximum stress at its most vulnerable.
Continuous glucose monitoring: stress hormones push blood sugar up too
Altitude is itself a physiological stressor, raising cortisol, and rising cortisol in turn pushes blood sugar up. That means glucose swings at altitude can be far sharper than at sea level, even without eating anything extra. A continuous glucose monitor (CGM) catches blind spots in your fueling rhythm in real time and prevents sharp glucose swings from dragging down performance and focus, which makes it an indispensable practical tool for long high-altitude endurance events. By wearing a CGM through simulation training, an athlete can see exactly how their glucose curve changes at different altitudes and different fueling points, and work out the fueling rhythm that genuinely suits them rather than applying generic advice.
Test the medication first: side effects vary from person to person
The side effects of altitude sickness prevention medication vary from person to person and must be tested during simulation training, not tried for the first time on race day, or the risk becomes impossible to anticipate. Verna admits that her past experience led her to delay taking it, and the result was a terrifying night with blood oxygen down at 70 — exactly the price of applying past experience to the present. Everyone's body differs in how fast it responds to a drug and how strongly it reacts, and the only reliable approach is to test it in advance in a low-risk simulation, record the response, and then decide on timing and dose.
Training load management: more training is not necessarily safer
In a periodized plan, load and recovery are designed as a pair, and there is a complete logic behind the training volume a coach prescribes — a recovery period follows a heavy load so the body has time to compensate, before intensity steps up again. An athlete adding sessions of their own disrupts that load curve, putting the body under extra stress before it has fully recovered and raising the risk of fatigue or injury the next day. Verna too was tempted to add training when she felt good, and only realized afterward that feeling good does not mean the body is ready to take more load. Following the coach's plan strictly is the most responsible thing you can do for your body.
Blood tracking: nutrients, endocrine function, inflammatory markers
Whether a blood report has flagged values, and whether the numbers sit inside the standard range, is only the most basic check. Meaningful tracking means watching how ferritin, estrogen, testosterone, cortisol rhythm and inflammatory markers such as hsCRP and CPK trend as preparation progresses — one normal result does not mean you stayed in good shape across the whole block. For example, long periods of low-heart-rate, high-volume aerobic training with energy intake that fails to keep up can easily bring estrogen and testosterone down together within a few months, combined with unexplained rapid weight loss, ending in a physical collapse that forces a complete stop. Schedule at least two or three blood draws during a preparation block and plot these markers as a line: that is far more meaningful than any single number.
Two illusions of preparedness that are most often missed
| Factor | Conventional focus | The YOUNGER functional medicine view |
|---|---|---|
| Rate of ascent | Whether you can reach the target altitude | More important than whether you can reach the target altitude is whether your rate of ascent leaves the body enough time to adapt — going straight to the summit means taking on risk you did not need to |
| Timing of preventive medication | Having the medication with you is reassurance enough | Side effects vary from person to person and must be tested during simulation training, not tried for the first time before the race |
Why do things still go wrong when preparation is thorough?
Verna's ten weeks of preparation were genuinely solid — the plan, the blood work, the simulation training, all of it done. And she still went through a terrifying night with blood oxygen at 70 because she delayed taking her medication. That shows systematic preparation is no guarantee: individual details, variables like drug response that differ from person to person, still need confirming in advance through actual testing rather than being carried over from past experience. Complete preparation means controlling every variable you can control while staying humble and alert about the part you cannot fully predict — not assuming that the more you prepare, the less can go wrong.
Supporting the body through a preparation block
If appetite is low before a race, prioritize staple carbohydrates such as sweet potato and rice to keep fueling. In the three days before going to altitude you can start gradually raising the proportion of carbohydrate, rather than eating a large volume at the last minute and burdening the gut. Iron is a common hidden deficiency in endurance athletes and affects oxygen-carrying capacity; vitamin B12 supports red cell production and energy metabolism; and electrolytes need active replacement given the pronounced diuretic effect at altitude. On training load, follow the coach's plan and avoid adding sessions that leave you fatigued or injured the next day. Schedule at least two altitude simulation sessions and record both blood oxygen and how you felt, so that the body already recognizes the environment before race day.
Real preparation is not grinding through on willpower; it is giving the body enough time to compensate and adapt. Ten weeks, three blood draws, two simulations — behind each of those numbers is the work of controlling every variable that can be controlled. When something goes wrong anyway, what matters is not blaming yourself for not preparing enough, but turning the experience into a more precise, more personal reference for next time.
The questions people ask most about high-altitude race prep and gradual adaptation
How do you prevent altitude sickness?
The most effective approach is to slow your rate of ascent so the body has enough time to compensate — above 2,750 meters, do not raise your sleeping altitude by more than 500 meters a day. Combined with gradual altitude simulation training, this lets the body recognize a low-oxygen environment before race day and lowers the risk.
What preparation does high altitude require?
We suggest at least a periodized training plan with recovery periods built in, two or more altitude simulations, testing preventive medication in advance, and blood tracking during the preparation block (ferritin, hormones, inflammatory markers and so on). Each has its own timeline, and none can be crammed in at the last minute.
What is a continuous glucose monitor (CGM) for in altitude training?
Altitude is itself a physiological stressor that raises cortisol and with it blood sugar, so marked swings can occur even without eating anything extra. Wearing a CGM catches blind spots in your fueling rhythm in real time and helps you find the fueling schedule that suits you rather than applying generic advice.
What should I watch for with altitude sickness medication?
Side effects vary from person to person, so we suggest testing your response during simulation training rather than using it for the first time on race day, where the risk becomes impossible to anticipate. Please confirm the actual timing and dose with a healthcare professional.
Build every race block on data you can actually read
If you are preparing for a high-altitude or long endurance event and want to know whether your nutritional, hormonal and inflammatory status can carry you through the whole block —
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