Put your back into something
Definition 1 of 1
Pro Tip 1/3Physical Effort
Originally meant physical effort, like moving heavy objects; now also means general effort. 
Moving this sofa will need us to really put our backs into it.
Pro Tip 2/3Figurative Use
Often used figuratively to describe mental or emotional effort, not just physical. 
She really put her back into learning Spanish, practicing daily.
Pro Tip 3/3Motivation
Suggests strong motivation and willingness to overcome challenges. 
He put his back into fundraising for the shelter, working tirelessly.