I had a leftover syringe and I closed the hole and pulled the plunger. It created some force from the atmospheric pressure. It made me think about why we are using metal weights for heavy lifting exercises. We could use vacuum instead. I searched on the internet and found only one occurrence that uses this idea, and it looks like it’s still in the ideation stage. The benefits are clear: no need for metal, everything can be made out of plastic, the equipment is lighter, and it makes less noise.
https://contest.techbriefs.com/2022/entries/consumer-product-design/12022