What does “MPB” mean?

In shortMPB describes the physiological process where muscle protein is broken down due to stress, training, lack of recovery, or calorie deficit. Growth occurs only if MPS exceeds MPB.

• High MPB: triggered by hard training, stress, poor sleep, or dieting.
• Low MPB: supported by recovery, sufficient protein, and smart training load.
• Balance: the net protein balance (MPS vs MPB) drives progress.

Practical keys for hardgainers

• Protein & calories: adequate intake helps reduce MPB.
• Training load: build volume via MEV — avoid living at MRV.
• System factors: monitor metabolism, NEAT, and BMR.
• Recovery: proper sleep lowers MPB — see SRA.

Common mistakes

• Always in deficit: increases MPB → muscle loss.
• Junk volume: overshooting recovery → see Myth 2.
• Ignored markers: chronic DOMS, strength loss, and poor sleep quality.

Implementation in practice

• Adequate protein: 3–5 protein-rich meals/day to keep MPB down.
• Deloads: planned unloading phases prevent chronically high MPB.
• Track: log sets, RIR, RPE, and fatigue markers.

Further reading

• MPS – Muscle Protein Synthesis
• MEV – Minimum Effective Volume
• MRV – Maximum Recoverable Volume
• RIR – Reps in Reserve
• RPE – Rate of Perceived Exertion
• SRA – Stimulus · Recovery · Adaptation
• DOMS
• NEAT
• Metabolism
• BMR
• Hardgainer

Keeping MPB under control

Hardgainer success happens when MPS > MPB. Protect your muscles with smart training load, sufficient protein, and recovery phases.