why can lung-bursting mean tiring, exhausting, wearing, fatiguesome?
i chanced on this word in the below sentence and i surmised its meaning as above. but i am very wondering how this word can mean that? is there any relation between lung, bursting and fatigue?

With eight laps to go in the men’s 10,000 meters, a lung-bursting 25-lap slog that is sometimes tedious but a feat of titanic endurance nonetheless, Kramer had his second gold of the Games all wrapped up.thank you guys, perfect

Question

why can lung-bursting mean tiring, exhausting, wearing, fatiguesome?
i chanced on this word in the below sentence and i surmised its meaning as above. but i am very wondering how this word can mean that? is there any relation between lung, bursting and fatigue?

 With eight laps to go in the men’s 10,000 meters, a lung-bursting 25-lap slog that is sometimes tedious but a feat of titanic endurance nonetheless, Kramer had his second gold of the Games all wrapped up.thank you guys, perfect

Answer

It can also be a question of lung capacity, as individuals differ.

Answer

Do any rapid exercise for as long as you can - run fast, jump rope, swim. Do it until you almost can't breath any more and then keep going. You will find that your lungs seem as if they will give out - even burst. You will also not be able to do anything else until you rest and get your breath back. You will be fatigued and exhausted - at least for a while. 
"Lung-bursting" is associated with having no more breath left, which in turn would be associated with something that makes you tired. It may be a short period of time, but you are still tired.

Answer

The author is trying to say that the race was so tiring that the runners' lungs could burst from breathing so heavily