The least likely explanation for this would be that they're training at different intervals, or one is training harder than the other.
The most likely reason is that the way the other person's genetics are most people cant gain muscle as well as others because of disease or their body structure.
Hope this helped!
Upper body strength and endurance :)
<h2>Excuse me what is there to answer</h2>
Answer:
By looking into data that shows what people eat and how it affects there life.
Explanation:
you can use this data to decide what is best for you and body.
