Cao_Cao wrote:I am already 20 years old but I'm small and skinny my height is 5'2'' I don't know my weight but I'm so skinny that I look like a skeleton.
Nothing wrong with skeletal. I was a skeleton at your age. It didn't matter if I was a glutton or didn't eat for days; I stayed at roughly 55 kg.
Cao_Cao wrote:I already tried eating food with high calories and carbohydrates and I also drink 3 glasses of milk everyday
I eat 4 times a day(6 am, 11 am, 4 pm and 8 pm)
High calories and carbs will just make you feel bloated and/or make you gain fat. You need a reasonable level of carbs to keep your energy up and protein to gain weight. Use a search engine to find foods that are high in protein and that you like. E.g. Fish, Chicken, Lean meat.
Cao_Cao wrote:I even still eat eventhough my stomach feels like it's gonna burst just because I want to gain weight
Too many carbs and high-calorie foods are probably to blame for that. Eat more sensibly and stop hurting yourself. I see from one of your other posts that you've developed a big stomach. My bet would be that you're gaining fat around your belly but nowhere else. Often, when you're trying to gain muscle you will increase your fat because high-protein foods can also be high in fat (e.g. chicken with skin, eggs, etc.). If you're working out and doing press-ups and sit ups et al then you're trying to get a muscular physique, right? Concentrate on getting that and then try to ditch the excess fat later. Skinny-ripped is a lot better than skinny-fat (not the oxymoron it looks like).
Gaining fat should probably not be your goal.
Cao_Cao wrote:I also workout 3-4 times a week. What do I do?
Concentrate on how you work out. Your body will adapt to whatever you throw at it (particularly at your age). So if you want to see gains you have to keep mixing it up. My advice would be to get yourself to a gym if you can afford it. Take a friend and buddy up. Friendly competition can help motivate you. You'll probably find people looking and feeling just like yourself there too. If a gym isn't your thing or it's too expensive then buy yourself some equipment: dumb bells and bar bells, a weights bench and plenty of weights, plus the all-important pull ups bar. Learn plenty of exercises and stick to maybe an hour long program every two days - recovery is just as important as exercising: You're building new muscle by damaging the old. Give it a day each time to rebuild. Change the program every 4-6 weeks to stop yourself from becoming too accustomed to it and always keep the weights challenging but not dangerously so.
Eat breakfast, don't exercise on a heavy stomach because it will only slow you down, and eat plenty of protein within an hour of working-out, preferably sooner.
Here's a another tip for you: Sit-ups do not reduce your body fat. Tighter muscles can tone an area, so a big belly can be pulled into shape a little by a strong set of abs, but working the muscles of an area will not target the fat content of that area. Just because an area has been pulled into shape doesn't mean its fat content has reduced any. When it comes to losing fat, forget the sit ups and do something aerobic.