Are there any possible risks of exercising (body weight, calisthenics only) at high altitudes? I'm talking of altitudes above 4500m. The whole premise is not to lose muscle mass.
Background: I'll be trekking in the Himalayan region for a couple of months this year. Most of the treks are in the range of 4500m-5900m. Since I'll be on many long hikes, I do not want to lose the muscle mass by not doing my regular workouts (all calisthenics, no weights/machines involved).
Please assume that I will have a good source of proteins. The question is purely on the any possible risks of high altitude workouts.
EDIT: Please consider a fit middle aged person with zero medical issues. Who is well acclimatized for the given altitude. I'm not worried about specifics of a person. I'm more interested in how high altitude workouts could affect a person. Mostly due to oxygen deficiency.