They are all young healthy professionals. It seems they do face some streaks in the schedule that may be taxing, but they can handle it. Wait until CW Version 2030. Chloe at 40, Hayley at 42, etc. Then they might need more breaks.
On a side note, wouldnt it be neat if in 2030 maybe some of their kids are also members of CW?
Like Doctor Who, CW regenerates. Of the original group, only Chloe and Mairead remain. The key is David Downes. Lovely Irish ladies who sing like angels can't be exactly common, but David keeps finding them. There's even a potential replacement for Mairead; go to YouTube and search on "celtic duelling violins." I'm not sure if Cora Smyth can dance like Mairead, but she plays the same grade of kick-ass fiddle.