Reply To: Dropping the interval
I do not prefer to go cold turkey. Those swimmers who respond well to the faster interval and make their goal time will stay at the faster interval. On the other hand, those who struggle will have their sets alternating between the faster time and the slower interval time. Once success is finally achieved then we try not to go back to the slower time again. Sometimes the slower interval time is good to revisit though if the swimmer is in a really bad funk for some reason.
Another adjustment I make is lowering the maximum number of repetitions when I go to the faster interval. This seems to have psychological benefits.