Catabolism

Metabolism has two complementary sides:

• Catabolism: breaking down (degrading to release energy), for example burning glycogen, oxidising fats, breaking down proteins
• Anabolism: building up (assembling, storing), for example making muscle, storing glycogen or fat

The two coexist all the time; what counts is the balance between them.

An original angle (catabolism is not the enemy): in fitness jargon, “catabolism” has become a dirty word meaning “losing muscle”. That is reductive. Catabolism is vital and beneficial

1. It releases the energy needed for life
2. It enables autophagy, the cellular recycling that clears out damaged components (a discovery awarded the 2016 Nobel Prize). A little “controlled catabolism” (fasting, exercise) triggers this anti-ageing clean-up
3. It removes faulty proteins

The problem is not catabolism itself, but excessive, chronic muscle catabolism (undernutrition, overtraining without recovery, prolonged stress/cortisol, overly strict diets).

The optimal balance: alternating catabolic phases (exertion, light fasting) with anabolic ones (meals, rest) is healthy: it is the body’s natural rhythm. Trying to be “always anabolic” (eating constantly) deprives the body of the benefits of autophagy. Catabolism and anabolism are the two legs of one stride.