What is the Origin of Lean Tissue Accretion Rates?

This concept combines 'Lean Tissue,' the biological component, with 'Accretion,' meaning growth or increase, and 'Rates,' signifying the temporal measurement. It is a term borrowed from body composition research to provide a precise metric for anabolic success, distinct from mere body weight change. It quantifies positive nitrogen balance execution.

What is the Mechanism of Lean Tissue Accretion Rates?

The mechanism involves adequate circulating levels of anabolic hormones, particularly testosterone and IGF-1, which stimulate muscle protein synthesis (MPS) via the mTOR pathway. Sufficient amino acid availability must coincide with this hormonal signaling to support the required substrate flux. Effective accretion rates reflect a positive balance where MPS significantly exceeds muscle protein breakdown (MPB).

Lean Tissue Accretion Rates

Meaning

Lean Tissue Accretion Rates quantify the speed at which metabolically active, non-fat mass, predominantly skeletal muscle, is synthesized and incorporated into the body over a defined period. These rates are a primary indicator of anabolic efficacy and recovery status, heavily influenced by hormonal milieu and resistance training stimuli. Maximizing these rates is crucial for functional longevity and strength adaptation. We measure the efficiency of building structural tissue.