45 minute workout

In the mornings I have allowed myself 30 minutes to workout. I just can not get up any earlier to do a longer one so 30 minutes it is. For the past 2 days my knee has been bothering me so I decided to take the morning off from my workout. I got up 30 minutes later, since that is how long my workout takes - right??, and proceeded to go through the rest of my normal routine. By the time I was ready to leave I was 15 minutes earlier than I normally am. Huh?? I got up 30 minutes later and was ready 15 minutes earlier?? How does that make sense??? So this led to thoughts of, does my workout really take 30 minutes?? Does it take longer including all the getting ready stuff? Is there some way that I could shorten the getting ready part and have a longer workout?? Hmmm....I'm going to have to time my routine and see....