Every cell in your body is constantly repairing, replacing, and remodeling itself. Protein synthesis is your body’s construction crew — taking amino acids from food and building the enzymes, hormones, transporters, and tissues you need to function. Without enough raw materials or the right signals, that construction slows down — especially as we age.

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Here’s what happens next:

• Leucine, a special amino acid, flips the “on” switch for muscle building (the mTOR pathway).

• As we age, that switch gets harder to flip — you need more leucine and total protein to spark the same growth.

• Exercise primes your muscles to respond more strongly to protein, making the repair crew faster and more efficient.

 

Chronic inflammation, stress hormones, and insulin resistance throw roadblocks on the path, slowing or blocking the signal to build muscle.

 

The good news:

• Lifting weights or even brisk movement makes your muscles more sensitive to protein.

• Eating enough high-quality protein — especially with leucine-rich foods — helps overcome the age-related “anabolic resistance.”

 

Managing stress, reducing inflammation, and keeping blood sugar steady removes the roadblocks so your muscles can respond. Think of it as keeping your “construction site” clear and well-supplied so your muscle-repair crew can work at full speed.