I was only able to ride once during the week last week. Mix in a lot of bad eating and late night studying (yay finals), I noticed the difference during the weekend. My usual Saturday group ride went horrible, heart rate was above the normal the whole time, and got dropped towards the end. Was sleepy the rest of the day. The next day I couldn't even get out of bed for the Sunday morning ride. But as others have said, it's a new week and time to go back to normal. Now I know the effects of bad eating and lack of riding even for only one week.