BAD DAYS/GOOD DAYS

Assuming the same course and that I am not doing something with varied intents (intervals, hill work, time trial, recovery ride), I tend to be within +/- .2 mph usually.  However, that's a pretty small sample size since most of my workouts have a targeted purpose. 

I have had a drop of 1-2 miles per hour for the same HR.  I took it as a warning sign of starting to over-train and dialed it back a bit for the next week. A slower bike time wasn't my only indicator as my swim and run times were slower as well along with a general feeling of fatigue.

I ride with a cycling group every week and yes you have good days and bad days.  Some days it feels like I'm invincible and I am hotly contesting every sprint, other days its all I can do to hang onto the back of the pack. The real indicator is if you have multiple bad days in a row. At that point you need to look hard at your training and most likely take some rest.

My bad days are often linked to poor nutrition or sleep, so that could be a good place to look first.

I appreciate ya'lls input.  I guess I'm just trying to hold on to hope.  I have worked really hard over the winter and have made significant improvements on the trainer, although there is room for a little error in my method of measuring progress.  But I was really looking forward to that first day of ideal weather so I could ride outside and see how my improvements translate to the road.  So I rode outside today and my performance was no better than a ride I did at this time last year.  I have my first sprint of the year on Saturday and was a little discouraged.  But since I got to work I have felt very drained and groggy.  So I'm hoping it was just a bad day for me.  I'll find out saturday. 

Don't laugh at this  I have a garmin speed/cadence sensor.  I never change the resistance on my trainer and I always make sure my back tire has same air pressure.  I have done a lot of interval workouts such as 4 X 5 min, or 3 x 10 min, etc.  I record my speed for each of those intervals and take an average of the whole workout. Then I  try to improve each time I repeat the workout.  I know it has nothing to do with real outdoor speed but I think it can be used as a measure of progress if all factors remain consistent.  Using this method I have made significant improvements but I realize that there could be minor things that could cause those measurements to be a little off.

Just a thought, but putting in a ton of miles on the trainer for me at least can be just as mentally draining as it is physically draining.  Being mentally drained can make you feel like you are tired, even if your body isn't really all that fatigued.  I find that switching up a routine, finding a change of scenery or just doing something completely different is sometimes enough to get me out of a slump where I'm feeling tired.  I added trail running into my run training this past year and felt dramatically better both mentally and physically.