The three problems, in the order they actually bite
The schedule, not the willpower
Nobody in this category fails because they do not want it. They fail because the plan assumed six sessions a week and an unbroken evening, and a single bad fortnight at work is enough to end it.
The fix is unglamorous. Three or four sessions, placed at the hour least likely to be taken away from you, which for almost everyone means early morning. Both branches open before the working day: Katargam at 5:00 am and Adajan at 6:00 am. A session you have finished by nine cannot be cancelled by a meeting at six.
The food, around a day you do not control
The second problem is eating. Skipped breakfast, a heavy late lunch, farsan with evening tea, dinner at ten. Not a diet problem so much as a scheduling problem that shows up as one.
The plan is built on what your day actually allows and on the food your household already cooks, which in Surat usually means Gujarati vegetarian food. Our guide to losing fat on a Gujarati diet works through the adjustments that survive contact with a real week.
What ten hours of sitting does
The third problem is the one people mention last. Neck and shoulders that ache by afternoon, a lower back that objects to standing up, a core that has not been asked to do anything in years.
Progressive strength work is standard, well-evidenced care for ongoing non-specific back pain of this kind, and it works by building the muscles that hold the spine in position rather than by stretching the sore bit.More on how that is trained, and on when to see a doctor first.