So, between 40 and 50 years old, mountain biker weighing about 90kg. No problems doing 100km on an MTB on or off terrain in reasonably quick time frames. Recently (couple of weeks ago) started doing burpees daily. Proper form, full press-up and jump, and initially felt like I was dying doing more than 5 or 6 of them in a set. Am now able to do about 25 in a set before literally feeling unable to jump or breathe properly. I will then go on to finish 30 after a minute pause.
Is this acceptable progress? I am a little discouraged to note that many people on the internet talk of doing 100 burpees in a single set as though it was not a problem, and apparently with no previous experience of doing burpees. Is that level of progress too low, that I should be looking at some possible problem, eg: diet etc?