Swimming and Spinning but what about running???
There's a lot of climbing/walking to be done on Aconcagua but swimming and spinning makes only sense for getting fit, not training the muscles you need on the mountain !!
Spinning and/or cycling is considered as bad if you do it without running as you're developing the "wrong" muscles which "get's in the way" with the muscles you need or will decvelop while climbing.
Yoga is nice but has nothing to do with training.
I agree with what Roger says about training. Good post.
I disagree with basically everything in the above quoted section.
Who consider cycling bad?
Cycling is excellent training for high altitude mountaineering. Sometimes before climbing higher peaks it has been my only form of training. Kuntner (R.I.P.) for example cycled long distances with a fully packed bicycle in odd parts of the world and considered that the best way to get fit for another 8000'r.
Still, this is just a detail.
The important point is; ALL
kind of training is beneficial for you. Don't bother to think too much about certain muscle groups, just train instead.
Your cardiovascular and lung capacity is really important up there and both are enhanced by any kind of training.
Swimming is good for this by the way.
One thing that I do consider not very useful on high altitude is a lot of muscles. Especially those really bulky gym guys usually have a hard time high up. Endurance is a key word, not weight lifter strength.
I'm not a believer in yoga.But
anything that can give you mental strength is good for you. That's what you need up there.
Joe Simpson once said he thought over 90% after passing 7000m is down to the mental capacity. I don't know if that's true, but for sure it's a very important parameter.
High altitude mountaineering is a lot about suffering and enduring.
Get ready for it.
All the training and right muscle groups in the world will not help you if you're not mentally strong.How
you gain your mental strength is not important. As long as you believe in your model, go for it.
Yoga may be the way for some.