How can I concentrate in studies over 4hour+?

you can listen to music as it helps a lot to concentrate.

Follow the pomodoro technique. Our brain cannot focus on for along time, it start finding distractions, so study for 50 mins and then rest for 10 and like this your brain will not get fatigue. Try keeping water and snacks while studying so that the thought of snacking doesn't bother you as well.

Listen to white noise, my playlist https://open.spotify.com/playlis..., green tea

listen to quality music while you are studying

@utsha_sarker In medical school, I found it most important to have a set schedule. Wake up at the same time. Exercise. Sit down in a quiet area by a window. Setup Spotify on a "Study Playlist". Disable any time consuming websites (eg, Reddit). Follow your study pattern that helps you the most. For me, I didn't like the pomodoro technique as I felt like my flow got disrupted, so instead, I set micro goals ("10 more clinical vignettes before I stop") before I could take a break. It takes a while to figure out what works best but eventually nearly all of my classmates could study 8+ hours a day for months. That much studying is not always needed though.

take breaks and do time boxing

I usually put my phone away and rest in intervals or when I feel like I'm loosing concentration.

You can try checking out the POMODORO technique for increasing productivity and being efficient.

I've tried using random 'techniques' that give you mini breaks inbetween but none has worked for me. I usually find heading to a local cafe and putting on lo-fi music is the best way I can stay productive over long periods of time 😆

Hope this might help..

A good night of sleep, stay hydrated (aka don't drink more than 2 coffees 😆), whatever you study, divide your tasks into sub-tasks so you see your progress, and quite frankly... take breaks!

you can find playlists on youtube. Music really does help. Also having a calm and quite environment

I would be eager to learn this too :)

I'd suggest study in chunks, instead of 4 hours straight

Yes, you can - with good music, high speed internet, quiet space, 20-25 oC and a computer. Everything is possible.

Changing subject focus every hour