Place a pencil on a table. Take a good, long look at it.
Now, try to pick it up.
Did you succeed?
If you did, you didn't try - you did it.
Put the pencil back down.
Now, once again, TRY to pick up the pencil.
If you are really trying to pick it up, it won't budge.
Try even harder.
Try as hard as you possibly can. Put both hands on it a give it everything you have.
See? Nothing happens except you get drained and eventually quit.
Now stop trying and just pick it up. See? How easy was that?
No matter how hard you try in life you will never, ever accomplish your goal.
Stop trying to lose weight. Stop trying to get in shape. Stop trying to improve your health.
Don't try - do. It's a lot easier that way.