Thanks for the query.
If a person has normal kidneys then exercise including muscle building exercise is quite safe.
In people with kidney problems like your son, regular aerobic exercise
is OK but he must avoid strenuous weight training
. Also he must not take any protein supplements
. All these will add to the work of the already affected kidneys.
However one thing is certain for sure that IgA Nephropathy
is not caused by exercise; it is more like an allergic disorder.
Hope this helps.