The short answer: Keep the training serious and the holiday enjoyable by choosing a frequency you can recover from.
Choose your anchor session
A morning class from 08:00–10:00 leaves most of the day open. An afternoon class from 16:00–18:00 works when you want to explore first. Pick one as the default instead of renegotiating the plan every day.
Start below your maximum
Heat, travel, unfamiliar food, and poor sleep can change recovery. One useful session is better than turning the first two days into an exhaustion contest.
Use the right pass
A 400 THB drop-in suits one visit. Weekly and monthly options reduce the per-session cost for a structured stay. The 10-session flex pass works when you want more schedule freedom.
Add private coaching deliberately
Use private training for a specific goal or correction, not because you think it is the only serious option. Request availability early and keep the rest of the itinerary flexible until confirmed.
Use current gym information
Prices, schedules, policies, and coach availability can change. Use the current prices and schedule, then use the training planner for the next step.