I saw the Nitro set on the Flowswimming website - and the distance swimmer in me got all excited (I sometimes hate that guy). The set was in yards and started at a 20 sec interval - then a 25 sec - keep adding 5 seconds to the interval all the way to 2 minutes - TRY TO DO AS MUCH yardage as possible. For example try to swim a 100 at the 60 sec - but then you also have to make the 1:05 interval and so on. But then the "sprinter" in me wanted a set to challenge myself - but still keep it a sprint workout + have to swim it by myself - this is actually a set which you can only swim by yourself -at your pace and rest:
Simple set: 20x25 - yards
Pace: race pace for 100 - I don't have a timer - but a digital pace clock - for me, I have to stay under 12 sec on all of them
Interval: Try to complete the set as quickly as possible, while maintaining the pace -- I will start on 45 sec interval and see what happens -- if it's easy, I can go to 40 or 35, if I start missing, I will add to 50 or 60s.
Record overall time and number of misses - repeat next week or week later.