How can I fix my jiggly belly and thighs after gaining muscle?

I am a 22 year old female.
About a year ago I started lifting weights and for some reason
my belly and thighs have become soft and feels liquid-like, jigglying even though I can see and feel the muscles. I have not lost that much weight (3/4 kg) for it to be lose skin.
How can I fix this, tighten by belly and thighs to stop jiggling?
Asked Apr 10, 2017

TIP: If it's not your answer to this question, please click "Leave a Comment" button under the question to communicate with the question owner.