Catabolism
Catabolism is the breakdown side of metabolism: complex molecules being broken into simpler ones to release energy. In a training context, the catabolism people worry about is muscle catabolism, where amino acids are stripped from muscle tissue to fuel other systems.
Why It Matters
Some catabolism is normal and necessary; your body cycles through about 1 to 2 percent of total body protein every day. The concern for lifters is when catabolism outpaces synthesis for long stretches, leading to net muscle loss. This happens during prolonged fasting, very large calorie deficits, or extended endurance work without protein.
Practical takeaways: distribute protein across the day, do not train fasted for hours on end if muscle preservation matters, and keep total calories within 25 percent of maintenance during cuts.
How to Spot It on a Label
You will see anti-catabolic claims on BCAA and EAA tubs. The claim is reasonable in fasted-training contexts but largely irrelevant if you ate a protein-rich meal in the few hours before lifting. Total daily protein matters far more than sip-by-sip timing.
Examples from real products
Related Terms
Keep learning with these closely-linked entries: