RE: Aches and training
That ache is DOMS (delayed onset muscle soreness) and unless you are training that muscle directly then go ahead and train. An example of of directly and indirectly is, Barbell rowing, biceps are indirectly worked whereas bicep curls are direct.
Unless you have bad DOMS in your legs which makes walking hard, and you are wanting to deadlift, give it a bit more time to heal. This goes for any muscle IMO, if the DOMS are so bad, give yourself more rest.
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