Kay well..First time going up against a person i was cocky and swore i was gonna win this sparring match and my cockiness gave me a Bump on the bridge of my nose. Now going into the ring i get nervous. Legs kinda get weak by it and stamina gets killed by the nervousness. I've never been knocked out but i was sparring my friend yesterday and he was 199Ibs and I'm 114Ibs and he hit me with an open glove straight to my forehead and i felt my whole brain shake lol. He didn't do it so hard though but he had power even with an open glove. I felt a sharp pain in the back of my head inside and later on i got headaches like around 12 am. Today i also had a headache but not as bad. Going on a heavy bag for rounds and rounds gets very exhausting just like it does fighting someone. Fighting will exhaust you faster. When exhausted your legs tend to give up on you and you get very sloppy. If you're very exhausted you just try to hold on or get away from the person to breathe. Thats the most i can help you with cause thats how i get if i'm exhausted