Training with hyperthyroidism

Hello doctors,
my friend was diagnosed with hyperthyroidism. He had this issue in his teens, recovered from it and now recently (about 14 years later) the symptoms showed up again. His doctor told him not to train /strain at all and rest until he recovers.
​​​​​He is currently not training at all and losing weight and apparently muscle mass as well. I am a bit concerned.

What would be your thoughts on training with hyperthyroidism, since I cannot seem to find other info or research (Google)

Thanks, and keep up the great material

Unfortunately without knowing more about the specific symptoms going on right now, as well as the specific lab findings pertaining to his thyroid function and knowing what treatment he is receiving, it’s difficult to comment on this.

I do not know what the doctor is hoping to avoid by limiting “straining”. Perhaps your friend could ask them.