There can't be many but cost might be one training and therefore enlightening them might make them more difficult to deal with They might have to take time off work They might demand higher wages They might leave to get a better job
The advantages are you getting fitter getting bigger mussels but the disadvantages are you getting heart if you are not careful i know this as i play rugby.
The only disadvantages I can think of is injury from not doing exercises properly, and you may have a decrease in flexibility if you don't do flexibility exercises with the weightlifting, but the...