Adrenaline Adrenaline. A hormone secreted by the adrenal medulla that is released into the bloodstream in response to physical or mental stress, as from fear or injury. It initiates many bodily responses, including the stimulation of heart action and an increase in blood pressure, metabolic rate, and blood glucose concentration. Also called adrenaline. We get them from many things that we do. Sometimes we don't even realise we are in adrenaline. One of the most easiest way to get it, Speed. Pure speed. Pure adrenaline. People seek adrenaline to wake themselves up. Some seek for the fun of it. Well, for people at our age, there's really only a few things that we could get this rush. Namingly, roller coaster rides, high speed drives in your father's car hopefully not getting caught, or the traditional 2 wheels of fury, the bicycle. Most people dont't realize that with only 2 wheels one could actually pass more than 50km/h and it's proven (well it's because i was mad enough to experience it for myself). After that rush has gone into your head, you actually feel more connected to what's around you. To put in simply, more alert. Attaining adrenaline highs on wheels, bikes are just what you need. Never has kinetic energy put to such great use, moreover just with 2 wheels, peddaling furiously like pistons in an engine and feeling that wind that crashes onto your face almost cutting(looking at the speedmeter which indicates 54km/h). Well, you know bikes, it's just you and your bike, no huge chasis and frames to cover your body, only you covering your bike, at that speed mistakes are costly. Basically, never underestimate your legs, and that one heck of a aluminium monster with 2 wheels.