If you are using a workout log, I have to say kudos to you! The fitness industry has determined that if you keep track of your workouts and/or diet by simply writing it down, you will be more successful! Many of us just keep track of our repetitions, sets and weight. This information is definitely beneficial to refer to when you workout the next time, but are you writing down your cardiovascular details? Probably not. What do I mean by details?
How long did you stay at your target heart rate zone? Refer to my blog on heart rate
How long did it take your heart rate to recover? Refer to my blog on heart rate recovery
If you are not keeping track of either of these times then you may stay at your plateau instead of pushing through it to the other side. You cardio program needs just as much attention as your strength training program.