A single minute can matter a lot in workouts. I cut the rest duration on last week's "attack" pursuit style intervals down from 5min between each to 3min and 4min today with no break into sets. All 4 reps back to back.
That **** hurt. I feel though it's a pretty realistic thing to have to dig and then ease into something that still hurts a good bit.
That first and second rep, it was awesome to see the HR peak after the 400w for a minute and actually go down while holding the 300w. Then taper back up. It held more on the last two sets obviously. Less rest.
Oh, and screw having to cough up or gag up phlegm or whatever during that kind of workout.