todays challenge: abs. either do your own or do a variant of this:
20 crunches and standing body twist warmup
a) several sets of 20-50 bicycle crunches
b) several sets of plank with alternating leg lift to finish you off
a) do at least 3 sets of 20 or 2 sets of 50
b) do at least 2 sets if you dont manage more than 30 seconds, at least one set if you manage more than 45 seconds
example:
warmup
4x25 bicycle crunches
50second, 50 second, 30 second planks
but again: do your own mix, see what works for you!