It is unusual, firstly, because it comes on the next day and, secondly, that only upper-body workouts tend to bring it on. This could possibly be an exercise headache, which is more likely to occur during hot weather or at high altitude. These headaches tend to last from five minutes up to 48 hours, and may be prevented by avoidance of excessive physical exertion. Your description could also be the most common cause of primary headache known as tension-type headache (TTH). I suggest you reduce the intensity and frequency of your upper-body workouts and keep a headache diary.

Source: Irish Independent June 01, 2020 01:30 UTC