Yes. Periods of anxiety and being scared allow the sympathetic nervous system to override the parasympathetic system.
The subsequent release of catecholamines such as adrenaline cause your heart rate and strength of contraction to increase, in order to supply your muscles with more oxygen and glucose. Your heart therefore gets a workout, just as it would if you went on the treadmill. Your blood pressure increases, as does your breathing rate and depth. These are all good effects. Continue reading Where do you define yourself?