Average speed returning to normal?

I have always been obsessed with data manipulation and since 2008 when I returned to regular cycling after the children were less dependant on me, I have kept details of every ride.  I have logged distance, time, climb, max speed, and average/max HR.  The latter figures were useful in helping my AF diagnosis, but the others were just used as motivation.

After every ride I would log the data and then produce graphs of average speed, climbing, distance etc.  for the month, quarter and full year; this was only for road or trail rides, I logged rollers and velodrome rides separately.

Up until 2015, I was generally averaging 16 mph over a rolling 12 month period.  It then started to dip slightly to about 15.5mph although until I entered persistent AF in February 2016, I thought I was just starting to feel my age.  I continued to ride under the guidance of the cardiologist and my 12 month rolling average dropped to 12.9mph just after my first ablation in April 2017. 

Three months after my second ablation the average started to climb again, hitting 14mph in August 2018 and 14.5mph in July 2019.  I am now (September 2020) finally back to 15mph and can see further improvements daily. 

In the graph below, the blue line is each day’s average speed and the red is the average speed of all rides in the previous year.

Since my return to health, the key difference to my riding is my max HR.  Before I developed AF, my rides were at an average HR of 155, with a maximum in the high 170s (ramp tested maximum was 185).  In order not to place too much strain on my heart I am currently on a self-imposed maximum of 163, although it is usually less than 160, and my average is around 135. 

I am now wondering whether I was as fit as I thought before AF kicked in, and my high HR was not me working to my limits, but my compromised heart struggling to keep up with demand.

2 thoughts on “Average speed returning to normal?

  1. Hey John, great to see your average steadily improving, and while keeping your HR under control. It must be encouraging to see those results.
    HR is something that occupies much of my mind too. I have not had an ablation but have had 3 cardioversions. The last one put me in NSR for 15 months and counting.
    I have always had a high heart rate, my most recent ride on the road was 56km and my average was 156 with the max being 174. I have long thought about trying to reduce this by doing a prolonged period of base riding only, in fact I did a few indoor Zwift rides (mainly because it is much easier to moderate my effort) with my HR averaging at 138 and max at 159. Is it your experience that lower intensity efforts for an extended period will somehow recalibrate my stsyem so that eventually I will be able to ride faster at a lower heart rate?


  2. Hi Sean, its a very good question, and I’m really not sure. Over my history of cycling (joined a club in 1976 at the age of 13) I never received any coaching. I always used to go everywhere at maximum effort and didn’t comprehend the idea of base training or rest days.

    My resting HR was very low, 48 when I was in my twenties, but on the rowing machine in the gym, I noticed that my HR rose quickly with exercise and became quite high. I never used a HR meter on the bike until 2008 by which time my heart was probably already expanded.

    After my ablations, I deliberately kept my HR low, by riding steadily along the flat. I also replaced my cassettes for ones with 30T; compared to 28 just before AF and 52/42 with 12/21T years ago. I now tend to sit and spin the lower gears more, where previously I would keep to a higher gear and power up hills.

    I am still self-restricted to 163 Max, but am approaching a pre AF fitness level. Slightly lower speeds, but much lower level of effort. I am now wondering whether I was as fit as I thought before AF kicked in, and my high HR was not me working to my limits, but my compromised heart struggling to keep up with demand. I wonder if what I am doing now is equivalent to base training and could possibly be increasing my fitness to a point where I may be able to hit my previous averages at a lower HR.


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