V12 Training Paddle

Here's another interesting graph from this arvo's 10km paddle. I didn't get anything done in the week after RnR mainly due to work piled up etc, so I got out today to blow away a few cobwebs. I set myself 10kmh as an average speed for the first 5km, however way it took to get me there & keep me on that speed.
You can see my heart rate rising steadily as I get slightly behind, finally reaching 5km right on 10kmh after a raised effort, but not really much speed by comparison, over the last 10 minutes. For the 5km back I concentrated purely on form, stroke length, breathing & leg drive, & didn't even look at the speed. 

The average on the way back? 9.9kmh, with a measurably lower aerobic output. There was no wind to speak of so it was all resistance work, but it shows how falling back on form is much more effective than trying to grind it out.