This is longer.
Basically, those face-lifting projects in beauty salons are useful, but they are really expensive.
If you make it yourself, you can use some tightened external products yourself, but the tightening effect of these things is very, very limited.
Therefore, the most effective method is: muscle gain and collagen supplement, and it must be adhered to for a long time.
It's easy to gain muscle. You are doing push-ups, which is one of them. I hope you also consider other muscle groups.
It is difficult to supplement collagen, and it is meaningless to eat collagen directly, because eating it will be considered as normal protein decomposition.
So the better way is to supplement a lot of protein, because you need to eat the same weight of protein to gain muscle. At this time, you might as well eat twice as much (for example, you weigh about 72.7kg now, and you need to take about 73 grams of protein in food every day, plus about 1.40 grams you can eat), and at the same time supplement vitamin C, preferably vitamin C in food, not pills.
We must persist for a long time.
Besides, let me answer your question.
"I am doing 450 sit-ups every day now. Does it affect those on my stomach?"
Yes, but the effect is very weak. Because sit-ups provide a well-defined abdominal muscle at most, but because the stomach is covered with skin or fat, you can't see the effect. Reducing fat still depends mainly on aerobic exercise.
"Thighs, arms and abdomen have thin lines. What method can be used to solve them? "
A better method is to directly use the products for removing stretch marks. If you are too young to buy such things, you can use vitamin E (puncture the capsule and squeeze it out to put it on the tattoo), or olive oil, or other essential oils that can tighten and remove the tattoo (such as lavender essential oil).