Japanese by Example
Learning through examples in manga

Too much to handle on top of class representative duties with 荷が重い

orange » Volume 3 » Page 121

Tako and Azu tell their teacher they want to participate in the sports day relay race. The teacher points out that participants have already been decided when one of the decided participants chimes in.

"I was also thinking I have too much on my plate as class representative."
"I'd be happy if I could switch out."