Taking collagen peptides while doing strength training leads to specific changes in muscle cells that support muscle function and repair, whereas taking a placebo during the same training only triggers general metabolic changes.

In young men who exercise recreationally, taking 15 grams of collagen peptides daily along with a 12-week strength training program results in greater gains in muscle mass and more changes in muscle proteins than strength training alone with a placebo.

Taking collagen peptides while doing strength training does not lead to greater increases in maximum strength in young men compared to strength training alone, even though it may increase muscle mass and protein markers.

Strength training alone helps middle-aged men build muscle and lose fat, but adding this collagen supplement makes those improvements even better.

In young men undergoing 12 weeks of muscle-building resistance training, taking collagen peptide supplements leads to a fivefold increase in the production of specific muscle proteins involved in contractile function, such as myosin and Z-disk components, compared to those taking a placebo.

Strength training with this collagen supplement doesn't make middle-aged men significantly stronger in leg presses than taking a placebo.