Climbing Ojos del Salado Volcano (6,893 m) is one of the greatest sustained-endurance challenges in the Andes. Summit day demands 12 to 16 hours of uninterrupted walking above 5,800 meters, over loose scree slopes, in sub-zero temperatures (see our guide to the best season, weather and wind) and with an oxygen partial pressure reduced to less than 45% of sea level. Physical preparation does not replace the physiological process of acclimatization, but a conditioned body delivers oxygen to the tissues more efficiently, lowers the metabolic cost of ventilation and prevents premature muscle exhaustion.
At Vulcano Expediciones, after more than two decades leading expeditions to the highest active volcano on the planet, we have seen that the main reason people turn back on summit day, after Acute Mountain Sickness (AMS), is premature neuromuscular fatigue of the quadriceps and hip flexors. A specific 12 to 16-week training plan focused on base aerobic capacity (Zone 2) and concentric/eccentric strength endurance is the foundation for an optimal safety margin on the Puna de Atacama.
The Short Answer: The 3 Pillars of Training for Ojos del Salado
Effective physical conditioning to attempt the 6,893 meters of Ojos del Salado requires a 12 to 16-week macro plan built on three key pillars: 80% of volume as Zone 2 aerobic work to maximize mitochondrial density and fat-burning efficiency; eccentric lower-body strength (Bulgarian split squats, weighted step-ups) to withstand unstable scree; and rucking sessions with a 15 to 20 kg pack to condition the core and upper back. This preparation lowers muscle glycogen use and prevents neuromuscular failure on a summit day of up to 16 hours of continuous walking.
[1. Z2 Aerobic Capacity] ──> [2. Eccentric Leg Strength] ──> [3. Core Stability and Rucking]
(O2 transport efficiency) (Support on descents and scree) (15 kg load at 5,800 m)
Macro Training Plan (16 Weeks of Preparation)
High-mountain conditioning is divided into four progressive phases. The workload should combine sustained aerobic sessions with gym strength sessions and trekking outings with a loaded pack on real terrain.
| Phase | Duration | Main Focus | Weekly Volume | Dominant Intensity |
|---|---|---|---|---|
| Phase 1: Aerobic Base | Weeks 1 to 4 | Building mitochondrial capacity and general strength | 5 to 7 hours | Zone 2 (60-70% max HR) / Base strength |
| Phase 2: Specific Strength | Weeks 5 to 8 | Loaded muscular endurance and core / back strength | 7 to 9 hours | Zone 2-3 / Pack load (10-15 kg) |
| Phase 3: Endurance Peak | Weeks 9 to 13 | Long-duration simulations and weighted stair work | 9 to 12 hours | Long days in the mountains (6-8 h) / Rucking |
| Phase 4: Tapering | Weeks 14 to 16 | Glycogen recovery, assimilation and mobility | 3 to 5 hours | Zone 1-2 / 50% volume reduction |
Vulcano Insider Knowledge: The most common mistake among athletes preparing for Ojos del Salado is overdoing high-intensity interval training (HIIT or anaerobic CrossFit). At 6,500 meters the body runs almost exclusively on aerobic fat metabolism. If your Zone 2 base engine is not developed, you will accumulate lactate at an unsustainable rate in the first two hours of walking from Refugio Tejos.
The 3 Pillars of Conditioning for the Roof of Chile
1. Developing the Aerobic Base (Zone 2)
Zone 2 is the heart rate at which the body mainly uses fat as metabolic fuel, with minimal blood lactate accumulation.
- Main methods: Easy continuous running, road/gravel cycling, incline treadmill or rowing machine.
- How to check: You should be able to hold a fluid conversation in complete sentences without gasping for the whole session. You can calculate your exact thresholds with our mountain training heart rate calculator.
- Recommended frequency: 3 to 4 times per week, with continuous sessions of 60 to 120 minutes.
2. Specific Lower-Body Strength
On climbs above 6,000 meters, the slope of the scree on the flanks of Ojos del Salado and the technical scrambling on the final chimney of Ojos del Salado demand constant mechanical effort from the quadriceps, glutes and upper body. Long descents put severe eccentric overload on the knees.
- Key exercises:
- Bulgarian Split Squats: 4 sets of 10-12 reps per leg with dumbbells.
- Weighted step-ups: Stepping onto a 30-40 cm box while carrying a loaded pack (10 to 18 kg).
- Romanian deadlift (RDL): Strengthening the posterior chain (hamstrings and lower back).
- Single-leg leg press: Correcting strength asymmetries before facing the scree.
3. Core Strengthening and Pack Conditioning (Rucking)
During the expedition, climbers must carry packs of 15 to 20 kg between camps (Laguna Verde at 4,340 m and Campamento Atacama at 5,200 m), as we detail in our guide to 4x4 logistics, huts and the Seismiles Route. To calculate and optimize your gear weight before leaving, you can use our pack weight and base weight calculator.
- Rucking training: Weekend hikes on local hills carrying a pack filled with water containers. The bottles let you pour out the weight at the summit before starting the descent if you want to protect your joints.
- Core stability: Front and side planks, farmer carries (Farmer Carries) and Pallof press to resist rotation when walking on snow or unstable scree.
Typical Weekly Schedule (Week 10 - Peak Phase)
Below is a typical high-load week in the final stage of preparation before the tapering period:
| Day | Training Activity | Duration | Details and Load |
|---|---|---|---|
| Monday | Active Rest / Mobility | 45 min | Dynamic stretching, foam roller and an easy Zone 1 walk. |
| Tuesday | Leg and Core Strength | 75 min | Back squat, weighted step-ups, Romanian deadlift and planks. |
| Wednesday | Zone 2 Cardio (Incline Treadmill) | 90 min | 10-12% incline, speed 4.5-5.5 km/h, keeping HR in strict Zone 2. |
| Thursday | Strength Endurance / Stairs | 60 min | Stair machine (StairMaster) or stadium steps with a 12 kg pack. |
| Friday | Full Rest | - | Complex carbohydrate loading and proper hydration. |
| Saturday | Mountain Outing / Long Rucking | 5 to 7 hours | Climb a local hill with more than 1,200 m of elevation gain and a 15 kg pack. You can check your pace with the walking time calculator based on Naismith's rule and adjust for slope with the grade adjusted pace (GAP) calculator. |
| Sunday | Cycling / Recovery Cardio | 90 min | Easy spin on flat ground to flush lactate and speed up venous return. |
Fitness Assessment and Field Tests
Before making the trip to the Atacama Region, it is essential to confirm that your fitness level meets the minimum safety requirements.
Recommended Fitness Tests:
- Loaded Step Test: Climb 1,000 continuous steps carrying a 15 kg pack in under 45 minutes while keeping your heart rate below the anaerobic threshold.
- 8-Hour Mountain Day: Complete an outing on mid-mountain hills with 1,500 m of accumulated elevation gain without cramps or extreme exhaustion at the end.
Vulcano Warning: Optimal physical preparation does not prevent Acute Mountain Sickness if acclimatization is ignored. Athletes with a high $VO_2$ Max often make the mistake of walking too fast at 5,000 meters, driven by their muscular strength, hyperventilating excessively and burning through their glycogen reserves before the decisive day. You can check how the partial pressure of oxygen drops with altitude in our altitude to oxygen calculator. For the recommended sequence of summits and rest days, see our progressive acclimatization itinerary and the Seismiles Route guide.
Summit Progression and Complementary Acclimatization
If you live in Santiago, you can do the weekend work on the city's hills: we laid it out in a 12-week plan, from Manquehue to El Plomo.
To get the most out of gym training and local hills, your preparation should be complemented with a progressive ascent plan on the Atacama Puna. Before taking on the guided ascent of Ojos del Salado Volcano (6,893 m), we strongly recommend testing your cardiopulmonary response on 6,000 m peaks with gradual acclimatization. Nevado San Francisco (6,018 m) and Cerro Barrancas Blancas (6,119 m) are ideal options for a first contact above six thousand meters.
For climbers who want to raise the physical demand and assess their muscular performance on unstable terrain, Nevado Tres Cruces Norte (6,030 m), Nevado Tres Cruces Central (6,629 m) and Nevado Tres Cruces Sur (6,749 m) make excellent endurance tests. You can also read our technical comparison of Ojos del Salado vs. Incahuasi Volcano to see the physical demands on another of the region's great summits, or the comparison of Ojos del Salado vs. Aconcagua.
To organize the full logistics of the trip, remember to check the guide to DIFROL and CONAF permits step by step, review the real cost breakdown, weigh the pros and cons of an unguided vs. guided expedition and prepare the necessary gear with the gear and clothing list for Ojos del Salado.
Frequently Asked Questions About Training for Ojos del Salado
Do air restriction masks (hypoxia masks) work to simulate altitude?
No. Training masks do not simulate the low barometric pressure of the high mountains; they only restrict airflow, increasing the resistance of the respiratory muscles (intercostals and diaphragm). Although they can strengthen the inspiratory muscles, they do not trigger the real physiological adaptations to altitude (such as the release of erythropoietin - EPO or the increase in red blood cell mass).
How far in advance should I start training if I don't exercise regularly?
If you start from a sedentary level or as an occasional athlete, on our expeditions we recommend a minimum period of 6 to 8 months. The tendon and joint adaptations needed to carry heavy packs on scree slopes take months to consolidate safely without causing tendinitis or shin splints.
How should I adjust my nutrition during the preparation months?
During the high aerobic load and strength phases, it is critical to consume between 1.6 and 2.0 grams of protein per kilogram of body weight to speed up muscle recovery. On long weekend outings, practice taking in carbohydrates regularly (gels, bars or nuts) at 40 to 60 grams per hour to get your digestive system used to processing food during sustained effort. To calculate your exact energy needs, you can use our carbohydrate intake and nutrition calculator.
