Originally Posted by
Brian Ratliff
Your body isn't stupid. It isn't going to use muscle for fuel if there's fat to burn.
Yeah, it will depending on the circumstance. Not likely in this case though.
It would be helpful to look at HR data, but absent that two days off after a bonk should be enough to restore glycogen levels, so it's likely that your body went into repair/recovery mode which will often result in a lousy performance coming off that break. It's why GT guys go ride on their day off.