Persistence will definitely have an effect. It took me less than a week to make 100 pieces every day. I feel my stomach is getting smaller, and my abdominal muscles haven't come out so quickly. The Korean one bought recently on Taobao looks better. You can search for a lot of Korean abdominal muscles on Taobao, or you can buy cheaper ones below 300. The effect should be too bad. Anyway, stick to it.