What kind of rice are you using? Brown, white, premium grain, instant, etc?
How many times before you do your cardio have you eaten in the day?
How much time is in between your weight training and cardio/what do you do first? I know you said you haven't done upper body in two weeks, but did you change your leg frequency at all?
You also need to remember that if your body is injured, all activities become more difficult, not just the ones that directly involve the injured body part. In addition, your shoulders are very important when it comes to running, or at least running with proper form.
What are you doing to fix the shoulder issue other than resting?
So you're doing cardio, outdoors, during the summer and you're feeling tired? Hmmmm you don't say? lol
OP, you said this has happened only twice? Nothing to panic about now. You're allowed to feel weak and tired every once in a while but if it happens every time you do anything physical I'd start to worry
i mean we did have a guy ask if he could run steps for his leg workout. So maybe I got body building wrong? I didn't realize running would help me create platz like quads - I may now need to buy a wheelchair so my legs dont get too big cause you know I want to fit in skinny jeans and such.
OP - conditioning, get a life, beginner are three better subforums off the top of my head that would deal with a question on running.