You will always be criticised by someone, no matter what you do. Whether it be in business, in hobbies you take up, or on your fitness journey.
One thing to note is that you will always be criticised by people who are not doing quite as well as you.
People who have been through the same struggles and successes will generally be routing for you, and willing you to succeed.
Whereas the people that criticise won’t be willing to do the work. They won’t be willing to get out of their comfort zone, and won’t be doing as well as you are.
The only way to not get criticised is to do nothing. To say nothing. To achieve nothing. And let’s face it, who wants that?!
You could turn it around. Think to yourself; you must be doing something right for people to notice you and feel the need to be negative towards you. They are just trying to make themselves feel good about their own situation.