I have tried a lot of different damper settings, and pulling rates, and here is what I have found for the most efficient use of my time on the rower:
Set the damper at 3 or 4.
Warm up for a few minutes; at least 5 minutes, at a very easy pull and strokes per minute. Start slow and work your way up to the faster pace, but do not pull hard. It is better to warm up for longer if you are going to do a hard row. I warm up for 10 minutes.
After the warm-up you will coordinate two things (and this takes some practice and watching): watch your "SPM" stroke rate (strokes per minute) and your "time / 500m" (not avg/500m).
For an easy workout I keep my SPM between 20 - 22, and my time/500m between 2:24 - 2:28.
For a little harder workout I keep my SPM between 22 - 24, and my time/500m between 2:19 - 2:24.
For a hard workout I keep my SPM between 26 - 28, and my time/500m between 2:12 and 2:19.
For a very hard workout I keep my SPM between 28 - 32, and my time/500m between 2:05 and 2:19.
For an unbearable workout I keep my SPM over 32, and my time/500m under 2:05.
To really get the best training for where your personal fitness level is, you really should use your own maximum heart rate as the multiplier for the training range numbers (go to
www.concept2.co.uk/training to see how to do this, and get the official training info). These numbers are based on my personal MHR.
While watching both of these numbers, I also break the workout into segments with rest periods in between the sets. The harder the workout level, the fewer minutes I can sustain it between rests. Rests are where I slow down the SPM and the pull to give myself a rest while still rowing.
A rest in between sets should last 2 - 3 minutes, but in some cases may need to be longer. You want your heart rate to return to it's warm up level (around 100 bpm for me) before starting the next set. If I am doing the easy workout, I don't do any rest periods at all, and at the hardest level, my rest periods end up amounting to half the workout time.
You should also allow at least 5 minutes for a cool-down row at the end of your workout, and don't forget to do some stretching afterwards.
If you row "by the numbers" in this way, it will force your body to become more efficient at the exercise. You will be training both your cardiovascular system and your muscles. In the end, you will be able to go farther in less time with your damper set to 3 or 4 if you do it this way.