Episode 135 | Field Notes – The Metabolic Cost of Bushwhacking
Episode Summary
In the Field Notes episode, we explore why bushwhacking miles aren’t just harder but metabolically different. The Metabolic Energy Mile (MEM) framework breaks this down into three types of work: brush work (muscle strain from pushing through vegetation), impedance work (lost efficiency from constant stops and detours), and hazard work (the stabilizing effort to avoid injury). Each inflates the Metabolic Difficulty Ratio (MDR) in unique ways, helping us better predict energy cost, travel time, and safety off-trail.
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together with Garage Grown Gear
Today’s episode of the Backpacking Light Podcast is sponsored by Garage Grown Gear, your hub for all things ultralight. Garage Grown Gear is dedicated to supporting the growth of small, startup, and cottage brands.
Show Notes:
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Featured Brands and Products
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The 3400 Southwest by Hyperlite Mountain Gear is an ultralight, minimalist backpack built from waterproof Dyneema composite fabric, designed for rugged multi-day hiking.
The Metabolic Cost of Bushwhacking
- Why bushwhacking feels disproportionately hard and how off-trail travel transforms walking from an efficient action into a complex, high-cost movement system.
- The Metabolic Energy Mile (MEM) Framework and how it quantifies energy cost through the Metabolic Difficulty Ratio (MDR).
- Three forms of off-trail work that increase metabolic demand: Brush Work, Impedance Work, and Hazard Work.
- Brush Work: the muscular cost of vegetation resistance and how vegetation density and drag elevate heart rate and energy burn.
- Impedance Work: how broken stride rhythm, reacceleration, and constant redirection through obstacles waste energy and create cognitive fatigue.
- Hazard Work: the metabolic and mental cost of instability, balance corrections, and sustained vigilance in hazardous terrain.
- How identifying the dominant work type (brush, impedance, or hazard) improves route planning accuracy, pace prediction, and risk management.
- The physiological triad of bushwhacking: resistance taxes strength, irregularity wastes motion, and instability drains control.
- Closing takeaway: bushwhacking is not random suffering but a physical system governed by resistance, rhythm, and stability.
Links, Mentions, and Related Content
- Dispatches: The Metabolic Cost of Bushwhacking: Brush Work, Impedance Work, and Hazard Work
- Wilderness Skills: The Metabolic Energy Mile Framework: A Systems-Based Approach to Measuring the Cost of Walking a Mile
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