I asked my friends at IIIT Hyderabad the toughest things they had to do there and most of them listed these two
Most of them believed that spending 1 hour daily just for exercise and yoga is a waste of time for a future CS engineer. No doubt, exercise is important but not at the expense of one's academics.
My sister was fortunate to study here with only a handful of the best people of her generation she ever met. IIIT-H and its associates have given the chance to move forward in their lives by instilling an education, character, and fearless attitude.
The toughest thing to be specific about is the check for free time. Academic deadlines or deadlines for assignments; deadlines for project proposals; GSoC deadlines, meetings, or maybe deadlines for paper projects. This stuff will always make you feel stifled a bit. Something will still be achieved. For any university student, the balance is difficult to find, but in the end, it is about your choices.
Apart from this, if you’re someone like my sister who finds yoga and physical exercise quite difficult then I think it is enough for a guy with a great BMI to do some 15-20 minutes at night. In chilly, cold winter and hot summers. And as far as yoga is concerned, my sister had plenty of that if it's intended to learn patience. And I don't think 1 hour of her precious day is worth investing. Apart from these, you’ll definitely miss your time here! So make a note of it.