Nah, you take one of the 30 gallon cans, stick a bag in it, and it can be a tough lift when full. Not so much because of the weight, though a twenty pound weight isn't going to be a surprise. It's the way you have to move to lift the bag out. It relies more on arms and back, so you can't really use your legs properly.

Without a bag, evena 15 gallon can is awkward to lift and walk with. A bigger one is again a more upper body thing.

Besides, I didn't say a woman couldn't get the job done, just that it makes more sense for whoever has the better upper body strength