I hope this doesn't sound flippant, but maybe while you're looking for a way to load your bike more easily, you could also try doing some biceps curls with dumbbells? I'm no spring chicken myself, but I know that all sorts of everyday tasks are easier when I'm going to the gym regularly. But you don't need to go to the gym to improve your upper-body strength a bit.

I know this isn't a quick solution--maybe not a solution at all, depending on your individual situation--but something to consider for the long term.