Wrist Pain When Playing Power Chords

I'm in Guitar Fundamentals 2 right now working through Chapter 3, and getting decent at power chords. However, whenever I play one of their tunes my wrist is cramping hard by the end, even though theyre no more than a minute long. I've tried straightening my wrist and turning the neck upwards but this either doesnt help or makes it super hard to play the chords. Any advice? Thanks!

One possible cause is that you are applying far more pressure than is necessary simply because you are concentrating on the chord changes and timing.

Try making a point of applying as little pressure as possible in order to get the notes to sound, and also take notice of if you're stiffening your arm or body during the changes or when playing in certain areas of the neck.