Okay, any kind of heart beating fast activities indicated the release of adrenaline. It would be bad at time to crave for adrenaline rushing activities because if you are in a stressful job or environment from morning. This is considered had because our brain calculates any kind of stress causing activity as fight or flight mechanism.
For example, you could be in fear of your teacher or your manager who wanted you to submit a coursework or project and the work is undergoing final changes. When you see them in fear, you would choose flight to avoid the uncomfortable answering session. But your brain will not act in a similar way. Your brain would interpret and react as the same way it would react when you are being hunted by a lion to be its next meal. Similarly things like working out in night at a trusted gym will evict similar responses from brain.
You might question the insanity and tell human brain is complex and most developed forms of brains available. But its hold be noted that dolphins have more evolved forms of brain but it is still considered not greater than human. Moreover, simple acts like putting a pencil between your teeth in your jaws would deceive your brain to think that you are happy and smiling.
Similarly, we were brought into the world with the reason to believe that we are another animal. Only the smart and the intelligent is fit to live since the survival of the fittest rule came up. This rule can be still seen in plants and other forms of animals. But human being became more developed and modernized. They started to make ways for all to live. We kept developing and developing. The nature tried controlling the abnormal speed of this growth by sending in plagues and other diseases. But human beings kept finding cures for these. Nature is the like the condemning mother, she will scold and slap you in your face at the same time she will give the medicine for it.
Now, coming back to the initial problem, though we have modernized and civilized, it is seen that our brains are wired differently. Thus when you are getting into adrenaline pumping activities it would be bad at a point for your brain. Chronic stress for long periods of time is considered alarming and an issue to the process of body. Check this site can helping you carve the right fitness of your body that can suit your needs.
Therefore, you can try talking a hot shower or soak yourselves in a hot water tub and light scented candles or candescent sticks and relax. If not, you can also try doing yoga or meditating in morning and nights. They seem to be good to help your remain calm.