I'm going from many years of no physically-demanding exercise at all to getting close to 30 of many of the basic exercises - so far, /every/ day is a 'challenge' day for me. But I'm getting better. :)

I'm feeling quite cheery today - today's routine was as non-excruciating as yesterday's, so it seems the modification's a definite success. Which means the choice between 'avoid eventual decrepitude' and 'avoid immediate pain' has tilted decisively in favor of the former. ;)