I found out that unless you “tire” your muscles during a workout, as you get older you lose the strength in them. How can I prevent this without making my arms bigger? Regardless of what anyone says, I know if I were to use high weights my arms would look huge. I have manly broad shoulders that I have been able to downplay because I’ve only toned my arms my using low weights and high reps. But can this prevent muscle tissue loss? I’ll say it right now, I won’t use anything more than 10 pounds or I will start looking like a man.