TrailGenic tested Salomon Shakeout shorts and tees alongside Arc’teryx Cormac and Merino wool shirts on Whitney, Langley, and SoCal high peaks. Here’s which base layers work best for heat, cold, and sweat management.
PurposePhase: TrailGenic™ Thermoregulation Layering Validation
Focus: Heat, sweat, and odor regulation under multi-stressor alpine conditions
Goal: Identify optimal base-layer rotation for balancing autophagy, comfort, and safety during fasted endurance climbs.
Performance Metrics
Test Routes: Mount Whitney · Mount Langley · San Gorgonio
Elevation Range: 6,000 – 14,505 ft
Conditions: Fasted state × altitude × temperature swing (35 °F → 78 °F)
Training Variables: Thermoregulatory stability · odor control · dry-time
Field Performance Summary
Salomon Shakeout – Everyday Go-To
“Hot SoCal ridges demand breathability over insulation. The Shakeout evaporates sweat almost instantly, keeping HR steady without cold-shock rebound on rest breaks. Ideal for Baldy or Strawberry Peak when temps climb early.”
Arc’teryx Cormac – Technical All-Rounder
“Worn under Gamma LT and Beta shells on Whitney. Managed sweat without cling, soft against skin even under pack pressure. Serves as a stable thermal buffer for shoulder-season ascents.”
Arc’teryx Merino – Natural Performance
“Cold dawns on Langley proved why Merino remains unmatched: warmth when still, cool when climbing. Odor-resistant through multi-day use — a quiet edge for long itineraries where recovery starts the moment you stop moving.”
Ella’s Reflective Analysis
1️⃣ The Science of the Stressor
“Base-layer choice alters the body’s evaporative cooling curve. In Electrolyte Timing and Cramping, we showed that maintaining surface dryness reduced sodium loss by ≈ 7%. Breathable synthetics like the Shakeout extend that window, while Merino’s keratin fibers modulate micro-humidity, reducing sympathetic over-activation during stress exposure.”
2️⃣ Integration Into TrailGenic System
“Rotation = resilience. Shakeout → daily conditioning; Cormac → shoulder season layering under Gamma/Beta; Merino → alpine missions. Link with the Fasted Hiking Progression Playbook to match layer strategy to metabolic state.”
3️⃣ Reflective Insight
“At altitude, the first layer becomes your second skin — not fashion, but function. When fabric breathes with you, focus shifts from sweat management to summit presence. Comfort becomes cognition.”