Energy Behind The Send: Bioenergetics Basics For Climbers

By: John Crawley, PT, DPT, OCS

In rock climbing, your “engine” is actually three separate systems working in concert. Whether you are sticking a desperate dyno or grinding through a multi-pitch day, your body chooses a specific chemical pathway to create Adenosine Triphosphate (ATP)—the molecule that powers every muscle contraction. Each discipline has differing demands for each system, yet no system can go neglected to optimize performance.

Understanding these systems allows you to target your weaknesses and train with precision.

1. The ATP-PC System (Alactic Phosphagen)

The “Power” System

This system provides immediate, explosive energy for efforts lasting under 15 seconds. It utilizes stored ATP and Phosphocreatine (PC) within the muscle. It is anaerobic (requires no oxygen) and does not produce the “acidic” byproducts associated with a pump.

How to Train It

To improve absolute power and recruitment, training must be high-intensity with full recovery to allow for complete phosphocreatine resynthesis [1].

• Intensity: 95–100% (Maximum effort).
• Duration: 5–15 seconds.
• Frequency: 2–3 times per week.
• Weightlifting Example: Heavy Deadlifts. 3–5 sets of 1–3 reps at >90% 1RM with 3–5 minutes rest.
• Climbing Example: Limit Bouldering. Attempting a move or a 3-move sequence at your absolute physical limit. Rest 3–5 minutes between attempts.

2. The Glycolytic System (Anaerobic Lactic)

The “Power-Endurance” System

When an effort lasts between 30 seconds and 2 minutes, the body breaks down glycogen (stored sugar) to produce ATP. This process is fast but results in the accumulation of hydrogen ions, which lowers muscle pH and creates the “burning” sensation or “flash pump” that makes it difficult to keep climbing. By training this system you can improve your body’s ability to manage the rapid accumulation of hydrogen ions and thus improve your power endurance.

How to Train It

Training this system improves your “lactic capacity”—your ability to continue moving while acidic byproducts accumulate [2, 3].

• Intensity: 80–90% (High effort, uncomfortable).
• Duration: 30–90 seconds.
• Frequency: 1–2 times per week.
• Weightlifting Example: High-Volume Accessory Work. 3 sets of 12–15 reps of Weighted Pull-ups or Rows with only 60 seconds of rest.
• Climbing Example: Select 4 boulder problems two grades below your max. Climb all four in a row with no rest. Rest 4 minutes, then repeat for 4 total sets.

3. The Oxidative System (Aerobic)

The “Endurance” System

The oxidative system uses oxygen to burn carbohydrates and fats for fuel. It is the primary energy source for efforts lasting longer than 2 minutes. Crucially for climbers, a strong aerobic system speeds up recovery between boulders and helps clear metabolic waste while you are at a “shake-out” rest mid-route [4, 5].

How to Train It

Aerobic training increases capillary density and mitochondrial efficiency, ensuring more oxygen reaches your forearms [1, 5].

• Intensity: 60–70% (Moderate/Conversational pace).
• Duration: 20–60 minutes.
• Frequency: 3–5 times per week.
• Weightlifting Example: Barbell Complexes. Using a light weight (30-40% 1RM), perform a circuit of 5 different exercises back-to-back for 2 minutes straight, resting 30 seconds between rounds.
• Climbing Example: ARC Training. Continuous movement on easy terrain for 20–30 minutes without getting a significant pump.

Summary of Energy Systems for Climbers

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Citations

1. Baechle, T. R., & Earle, R. W. (2008). Essentials of Strength Training and Conditioning.
2. Giles, L. V., et al. (2006). Physiologic responses to indoor rock climbing at different incline angles.
3. MacLeod, D., et al. (2007). Physiological determinants of climbing-specific finger endurance and sport climbing performance.
4. Fryer, S., et al. (2015). Hemodynamic responses to intra-thoracic and intra-abdominal pressure changes during rock climbing.
5. Schöffl, V., et al. (2006). The physiology of rock climbing.