Ok, so concentrate on the muscles you need to develop (for most the hamstrings). Make sure you do it at least 4 hrs after the last race following a hot shower and do a pulsing warm-up for 5 to 10min before the power contractions. You might consider doing 5 or 6 reps of 5 to 6 sec duration with a 50 sec break, depending on how you feel after the race and pulse down after as well.
You could repeat this session after short speed on Mon (assuming you are using the meets for your SE needs and that the Wed session will be sub-max)
Of course, you can use the stim for a pulsing massage anytime