When fighting or training heavily you can get a great rush from adrenaline. Learning to control that burst, and level it out over the length of your training while increasing your intensity can really drive your body. Some people feel nervous, as their body begins burning more energy and breathing rapidly, control your faster breathing, and feel the charge within you. Use that with a focused and disciplined mind and you can achieve amazing results.
Appreciate your heightened senses
Breath deeply, fully and quickly
Try to hit new personal bests for power or strength
Learning to control the rush will improve your endurance, panicking will burn you out faster
Feel the excitement, but keep on track, focused power is better than wild flailing.