Do you do much low intensity recovery work after those bike rides? Light exercise hits a sweet spot where the raised heart rate helps clear out stress hormones from the high intensity work but isn't so intense that you are adding more stress.
If your heart rate takes hours to get back to resting after a ride the answer is no. Adding 15 minutes where you intentionally go slow and target zone 1 will cut that time back to resting way down. Less stress exposure, quicker recovery because you are starting to recover sooner, and less low energy time from being exhausted by the workout.