Good Days and Bad Days – a comparison of two steady state sessions

I have been wondering about good and bad days.

On Monday, I did a session that was prescribed by our coach:

2.5 km warming up, 15min/2min, 20min/3min, 15min, 5 min cooling down

All was to be rowed at 20/21 spm. The circumstances:

  • Rowed the day after a pretty good 4x2km
  • Overall feeling “above average”, HRV 7.2, morning pulse 55, fatigue low
  • Music was pretty monotonous techno rock for workouts

This was the executed Monday session:

Stats from

  • rPower = 197W
  • Heart Rate Drive = 5%
  • rScore 79
  • TRIMP 129

Note that I did row at lower stroke rates than prescribed. To break the boredom, I did rate ladders, starting at 18, up to 22spm, than oscillating between 21spm and 20spm, and finally down again.


The plan was another steady state session, but there was a guy doing a quick repair on one of our Water Closets. Long story short: The quick repair turned out to be a total replacement of the WC, which I needed to assist with, including driving to the hardware store to buy the thing.

Perhaps carrying old WC down the stairs and new WC up the stairs can count as strength training?


  • Rowed after an unplanned rest day
  • Overall feeling “above average”, HRV 7.7, morning pulse 46, fatique low
  • I listened to the latest podcast (“Small Puddles”)

The HRV value is higher (worse) but overall I am on a decreasing HRV trend since I came back from travels. Here is the executed Wednesday session:

Stats from

  • rPower = 186W
  • Heart Rate Drive = 6%
  • rScore 81
  • TRIMP 119

On Wednesday, I was free rating but I intended to hold 195W and higher (blue in the chart). I pretty much succeeded and the workout felt very easy.

The mental trick I played was dividing each 20 minute interval into five 4 minute intervals and focus on some aspect of my rowing for four minutes.

So in Summary:

  • Monday – lower average power, workout felt hard
  • Wednesday – higher average power, workout felt easy

Here are the comparison details:

Orange is Wednesday. Higher power.

Interestingly, despite feeling easier, my heart rate was significantly higher on Wednesday.

The chart above clearly shows the different approach to rating.

In terms of Average/Peak force ratio, the workouts are nearly identical.

However, on Monday the average and peak drive force was higher. Also, the drive length was a few centimeters longer:

All this resulted in a significantly higher Work per Stroke value for the Monday workout:

I find this highly interesting. It shows how small things can have a big impact. To summarize:

  • I was on an improving trend in terms of being rested (HRV, resting heart rate)
  • On Monday I was sore from a hard workout on Sunday. Wednesday was done after a rest day
  • I eased up, shortened up slightly, and adapted the rating to get the desired power output

Three things that are small, but the synergetic effect is huge.

Also shows how unreliable Heart Rate is as a measure of fitness. I wish I had done Lactate measurements for these two workouts …