I have been doing 5 days a week, a bit more on the weekends if I can fit it in!  That’s the advantage of being retired!  I try to do the challenge after breakfast, and go into our home office where I can put the challenge on my computer.  Making the time every day to do the challenges had helped me immensely.  I understand why it has been stressed so strongly.  I see some improvement every week and look forward to each week’s lessons.