In all fairness "picking up 40 lbs" (note: little less than 20 Kg, for the rest of the civilized world) and being capable of THROWING them few meters away are two very different things.
40lbs really should be that heavy to pick up and toss, even toss a little bit. Right now a 17 strength person cant even pick up a 40lb halfling.
Here's a example a average big dog food bag will weigh roughly 36-40lbs. I can pick that up with one hand and throw it.
