For me the 2nd consecutive brisk to hard ride in a row will see a lower heart rate than the 1st day out of recovery. However after a few days you'll see fatigue and even lower heart rates and that would indicate overtraining, time to take time off. Resting heart rate rise is also an indication of overtraining. If it's too high you're overtrained. When I hit recovery mode I watch my heart rate. Usually within 24-36 hours after hard workouts it comes back down into the high 40s. Upper 50s for me is when I'm overtrained. Watching your heart rate continually and consistently will give you this sense of training. Good luck.