few suggestions to build the stamina (during your study sessions):
1. Try grouping your study into 75 mins of chunks. i.e. study for 75 mins for 1 topic, take 8-10 mins of break, then study for 60-75 mins again. So that you get used to the GMAT test routine. Take a longer break (atleast 2-3 hours) after this second session as you wouldn't want to burn out yourself.
2. Dont accumulate your fatigue by studying all 7 days a week. Keep atleast 1 day off and do some activities which you feel unwinds your brain fatigue. On average 10-14 hours per week is what works with the most.
3. Take enough sleep! Atleast 7-8 hours per day.
Suggestions (for your test)
1. Give the tests during your most productive time of the day (avoid taking full tests late evenings after having a long day). Find out what time best suits for you and schedule the actual GMAT during similar time slot.
2. Take splash of cold water during each break of your test. Trust me, this thing really does the trick and freshens your mind up for the next challenge.
3. If you feel stressed out during the test, take your eyes off your screen for 4-5 seconds and focus on lines on your palm or seam of your shirt/jeans or just close your eyes for 4-5 seconds.
Read Stacy Koprince's (
MGMAT) article. Its immensely helpful!
https://www.manhattangmat.com/blog/index ... you-crazy/Do what suits best for you!