She started going to the gym to tone up her muscles.
body
Frequency:
70
%
He followed a strict diet to tone up his body.
abs
Frequency:
60
%
She did a lot of crunches to tone up her abs.
arms
Frequency:
50
%
He lifted weights to tone up his arms.
legs
Frequency:
45
%
She did squats to tone up her legs.
Idiomatic Expressions for tone up
Phrase: tone up your skills
Meaning: to enhance or improve one's abilities or expertise in a particular area
Usage: I've been taking online courses to tone up my coding skills.