Repetitions in reserve (RIR) and rating of perceived exertion (RPE) are fantastic methods of auto regulating and determining training load. These methods can be adapted and slightly modified to work with kettlebell sport. Repetitions above or below your steady state pace in the last minute of the set would be considered RIR.
For example, if you did a six minute set of long cycle, with five minutes at 6RPM and the last minute at 10RPM, you would have 4 RIR. Alternatively, if you did this for repetitions, you would have a RIR -2.
A coach can use the number of RIR to determine how hard the set was for you. So, if you had 4 RIR you could increase the duration or RPM, but if you were a -2 you would repeat the set, aiming to perform at a steady pace.
The other benefit of RIR is that it offers an insight into how hard the set was, so if you had a RIR of 10 you might in turn have a large overload. However, a RIR of 1 might suggest a small overload.