I use to work with paper (Shipping and Receiving) and spent most of that time lifting 50-80lb boxes of office paper. After a while I started to realize the way Ive animated people lifting, was never how I really lift things. When acting it out you’re doing it while thinking about it you’re tying to portray it being heavy.
In reality you want to lift it like its the lightest thing possible and make it easy to do by; shifting your weight, leverage, body position. Theres also other things to take into consideration when putting this into animation; anticipation, squash and stretch, timing…etc
One thing that i noticed is when lifting something thats: heavy, low to the ground and wide or awkward. I would be on one knee in a squat. Then shift the weight of the object onto my thy, this brings the weight instantly to my center of gravity and now I have the strength of my thy supporting the weight and providing leverage for when i stand up.
Now if i were to lift this any higher than my midsection, my center of gravity would rise and even extend outside my body, causing me to stumble while trying to regain control.
Your character lifts it straight up and has no struggle. which is why it appears to loose its weight.
Now i gather hes trying to “shot put” it and it doesn’t go far. Once he removes support of the ball, it will drop straight to the ground with little or no bounce, Something of that mass would have high momentum, meaning it would require more energy to move. he might take a few steps back to give it some thrust. but if its REALLY heavy it will be just a dead thud as it dents the ground.
The moment he loses the ball will also will change his center of gravity suddenly. You could ad some comical elements, such as him falling forward onto the ball and giving a little grin or thumbs up. Or not falling over but being extremely exhausted and tries to raise his hand for a “fist pump of victory” but cant raise it above his head.
I know i might have thrown a lot at you, but take it in pieces, just like the animation, time it all out, break it down to key poses, then work it into motion. Get goofy and film yourself as reference. Being an animator often means you have no shame…
i remember when my girlfriend found the “reference” tape i made. “Are you Dancing? you never dance!? Oh now what are you doing?”