GLOSSARY

Oxidative Enzyme Activity is activity of enzyme markers of oxidative pathways.

Training can change enzyme abundance, regulation or activity capacity depending on mode, intensity, volume and training history. An acute session response is not the same as chronic adaptation. Oxidative or glycolytic markers describe only part of performance; oxygen delivery, fuel stores and neural coordination also matter. Practical assessment therefore combines performance and recovery outcomes with adequate nutrition and the actual training program rather than relying on one enzyme marker.

Measured activity is conversion per time under assay conditions rather than simply protein abundance. A substrate-rich assay may reveal potential capacity, while living tissue has different constraints and regulation. Units, tissue normalization and preparation methods are needed for comparison. Blood activity is not identical to intramuscular activity; laboratory changes require exercise timing, symptoms and tissue origin rather than being read as direct performance measures or a standalone diagnosis.

Enzyme abundance reflects protein synthesis and degradation; gene expression, RNA, protein quantity and measured activity are different layers. Induction and repression need definition because expression and activity can differ. Constitutive does not mean a perfectly constant amount under all conditions. In exercise interpretation, long-term capacity changes must be separated from rapid activation of existing enzyme and from actual pathway flux rather than treating them as interchangeable findings.