The hamstring one is amazingly effective. Gallon jugs of water was the best that we could ever do for biceps
but
they are only 8 lbs. ( girly!
)
jugs of cat litter might work but you'd have to bend forward and brace with
your other arm to get enough of a resistance through the whole arc.
Giant Rubber Bands from an office supply store is what we used before
the resistabands.
OH! I just remembered another.
If you can get a bar that will hold your weight and put it across
two counters, hang underneath and do a close-grip pull up
You'll want your heels on the ground...maybe your whole foot