Not onerous at all. I passed in December. 72kg and 1.67m
Or about 150lbs and 5' 7"
MRI, ultrasound, etc. Thorough of course, but every initial Class One is.
I passed the Indian Class One in 2012 in Bangalore at the Air Force place.
I am no athlete, age 51.
The rumours about the standards seem to be conveyed by fat US guys who fail on BMI or stress ECG and cannot accept that away from FAA they are not deemed fit.