What causes fat loss breakthrough....constant movement(moving around) or working out until muscle failure?

for your stomach you should do sit-ups also try finding something heavy and keep it against you stomach while you go up and down. and one more thing when you get to a point where you cant do more stop for like 10-20 seconds then keep on going and take it easy you never want to push your self then just stop because this can actually loss muscle doing this you must push yourself then slow down rest-slow down rest-slow down rest- untill you can do like 10 without felling a burning in your stomach