What is the Origin of Performance Substrate Availability?

Rooted in exercise biochemistry, this term describes the supply side of cellular energetics. It focuses on what is readily available in the plasma to fuel muscle contraction or neural activity, distinct from total body stores. The relevance to hormonal health lies in how substrates influence insulin sensitivity and substrate preference.

What is the Mechanism of Performance Substrate Availability?

Availability is governed by the balance between substrate mobilization (e.g., hepatic glucose output, lipolysis) and tissue uptake during activity. Hormones like insulin, glucagon, and catecholamines tightly regulate this balance. Insufficient substrate availability forces reliance on less efficient pathways or leads to premature fatigue, signaling the body to shift its hormonal milieu toward a more catabolic state to mobilize reserves.

Performance Substrate Availability

Meaning

The assessment of circulating levels of the primary energy substrates—glucose, fatty acids, and amino acids—that are immediately accessible to tissues for meeting acute or chronic energy demands, particularly during physical or psychological stress. Adequate availability ensures optimal mitochondrial function and supports necessary anabolic/catabolic hormonal responses. This metric directly impacts endurance and recovery.