Is the Sinharaja trek physically exhausting.

The standard primary walking trails specifically near the highly popular Kudawa entrance are incredibly flat very wide and completely heavily shaded by the massive dense towering canopy above. You absolutely do not need to be an elite highly fit athlete to deeply enjoy the primary forest. However the absolute main physical challenge is the incredibly brutal relentless tropical humidity. Because the thick jungle completely blocks any cooling wind you will sweat massively intensely even while walking very slowly. Bringing multiple massive bottles of drinking water and walking at a highly relaxed slow pace makes it perfectly manageable and completely enjoyable for older tourists.