About being light headed. I haven't experienced it but my friend did. Based on my observation, it was because he didn't load up on complex carbohydrates an hour before hitting the gym and he also tended to quickly ramp up his heart rate by not warming up gradually.
I follow the usual routine of eating a healthy breakfast, a granola bar at 10 am, healthy lunch, lots of complex carbo and some lean meat at 3 pm, and a granola bar again an hour before I hit the gym. At the gym, I do some low intensity cardio for 15 minutes and then followed by dynamic stretching. Resistance and then cool down (I either walk or spin) and then static stretching. If I missed my carbo-loading an hour before the gym, I cannot perform as well.
I also do some plyometrics every weekend and while I do pant, I never felt light headed. I'm a bit worried about my knees though because a few of my plyometrics involved jumping forward and sideways.