There are several possible causes of this tremor.
Sometimes, with lots of physical exercise, the muscles and nerves can become fatigue and this can lead to twitching or shaking because of the fatigue. If the symptoms do not recur, or if you can associate them with exercise this time around, then you probably do not need to worry
Simple tremors can sometimes run in families and may appear at any time. These types of simple tremors are typically worsened by fatigue and caffeine, and the often improve a lot when caffeine intake goes down and the person is well-rested.
Of course, rarely, shaking like this can be a sign of a seizure or other neurological problem. This would be unlikely in hour case, especially if they do not come back. However, if the symptoms persist, or if you have any other concerning symptoms, such as headache, dizziness, visual changes, loss of consciousness, or weakness, then this could be a neurological emergency and you should be seen by your doctor
or go to the emergency room immediately.
If you do not have these warning flags but the symptoms still persist, you should see your primary care doctor
soon to make sure something serious is not going on.