problem with my arm

[Taishar]

Hey people. Does anybody here get tired from running? Not your legs. Your arms. Sometimes when I run my arms are dead tired, but other times nothing happens. And ya know how when you stand and put ur palms on your thighs theres and outside and an inside side where your armpit is? The muscles on the inside, are they your triceps? What muscle is it and how can I work it out?? IF you stick your arm out with your palm facing the side, I want to work on width of my arm from side to side and not the length going up and down. Thanx everyone!!

[abrannan]

This model is facing to the right, palms at the side. I'm having trouble determining which muscle you're referring to from your description. Help me out?

[Taishar]

erm....I think they are the triceps and the... Brachialis? Yea. Thanks!

[abrannan]

To work your triceps I recommend push-ups and dips. You triceps are involved in most arm extension type movement, so most any arm exercise will work those muscles.