Conversion Chart Part II

First I’d like to thank all of you who’ve send emails and comments regarding my last Conversion Chart posting. There was some consistency with the questions and comments that were sent. I will try to accomodate the main points that were made.

I’d like to first clarify that the 20-point Borg scale is has its name because the highest level is 20. There is only 15 levels on this scale, 6-20. This scale is also referred to as the 15-point Borg scale. For my comparison level zero (10-point Borg) is equal to level six (20-point Borg). Looking at the comparison of these 2 scales with thoughts of what we are trying to achieve by adding power into it, it seems like Coggan’s approach of using the 10-point scale makes the most sense. Level one (10-point Borg) seems to be a simpler starting point for Active Recovery than level nine (20-point Borg). In terms of power you’re not going to be doing anything below your Active Recovery zone so all of the levels from 6-9 on the 20-point Borg scale are redundant. More on this here (Andrew Coggan, thank you for sending me the link)

I received another good analysis of this conversion from cycling coach, Mr. Steve Neal. Correct me if I’m wrong, but I believe that Steve Neal is/maybe affliated with Crossfit Endurance (CFE). I make this assumption because the guys behind CFE, Brian Mackenzie and Carl Borg are also copied on the email. Please take a look at his findings here. You may want to save the pdf so that you can refer to it in a different window while reading along here. steve-neal-conversion-chart

Our conversion charts are similar. The biggest difference is how we are scaling a 100% effort. On Steve’s chart he is basing a 100% effort on an athlete’s VOMax number. On my chart I am basing it off an athlete’s threshold number. My difficulty with this is that Steve’s does not correlate with Hunter Allen and Andrew Coggan’s methodology (TrainingPeaks) which he is using to derive his power ranges. Those ranges are derived from the athlete’s threshold power not their VOMax power. For this reason I think that threshold power should be used as the 100% number.

You’ll also see that level 20 on the 20-point Borg chart is called “exhaustion”. Based on this, I do agree with Steve that it would make sense that VOMax or Anaerobic should be at level 19. I believe that this is one of the things that Coggan’s avoided by 1st converting the 20-point chart down to a 10-point chart. On Coggan’s chart Anaerobic is power exceeding level 7. Deriving power zones from the 20-point chart seems tricky. Using 10-point levels things out. If the power zones that you are using are those that were created by Andrew Coggan I believe that you should follow his methodology on how they were created in order to maintain consistency when incorporating them against the CFE model.

Now comparing Steve’s model and mine against CFE workouts.

When I created my chart I sought out a CFE workout with a very high RPE level to determine if my chart worked on the top end workouts. Example, on November 16th the workout is called 95% Tempo, do 18 miles at RPE 18-19. Per Steve’s model you would be doing 18 miles at VOMax. Per my model, you would be doing 18 miles at Threshold. VOMax is generally a zone that an athlete can maintain for 3-8 mins. No one can do 18 miles at VOMax. Steve’s chart can not work here. This is why I use your threshold power as 100% similar to Coggan’s levels, especially since your threshold test is used as your measuring level for determining power zones.

On CFE, Time Trial workouts are identified as…time trial workouts. To my chart this would be an RPE of 20. Per Steve’s chart these workouts would be an RPE of 17-18. These workouts are titled Time Trial workouts. If they were to be done at RPE 17-18 I believe that they would say so.

On to CFE tabata workouts and all out efforts… There is no RPE assigned to these workouts. I interpret this to be off the 20-point RPE chart. The 20-point RPE chart has level 19 labeled as “very, very hard”. Level 20 is Exhaustion. I feel that you can go harder than “very, very hard” before being exhausted. After “very, very hard” I feel that you can go “all out” before becoming exhausted. These are anaerobic efforts. Steve does not account for this in his breakdown against the 20-point scale. Something has to go between VOMax and exhaustion.

On December 30th, Bike : RPE of 12 for 30 minutes… Do Not Exceed 12 RPE for the first half of this effort. If you feel good, increase RPE as to how you see fit… Just never go below 12 RPE. Per both of our charts, this would mean ride for 30mins at Endurance. Do we or CFE consider Endurance to be equal to LSD? Steve’s chart states this zone to be an area “for longer sessions”. What do we expect to be the benefit to doing only 30mins at this effort? Granted 30 mins would not qualify as the ‘L’ in LSD. CFE strongly argues against LSD. Despite the discrepancy from my chart on this day I did my 30mins at the low end of my Tempo zone. RPE 12 is the lowest level workout that I’ve seen on CFE with exception to days that you should ride “easy”. If the CF and CFE models are based on high intensity training, the endurance zone should have no place in a workout.

CFE workouts are tough. The intensity in its workouts are super tough. I’m confident that they will be effective. I’ve already seen proof in my own fitness. The story will be more complete as time goes on. You can only expect your threshold numbers to increase based on the sheer number of workouts spent training in the Threshold power zone. Again I value everyone’s feedback to my posts. Your opinions and thoughts are great. I will continue using my conversion chart as it is currently designed. (see below) Stay tuned for my findings with my experiment.




  1. Great site!! Thanks for the conversion table, gedtting my power tap next week…cant wait!!

  2. Awesome, good luck to you with the Powertap. Let me know how things go.

  3. […] Conversion Chart Part II […]

  4. Thank you for your chart and excellent analysis. The points that you make in your comparison are excellent and make a lot of sense. Thank you for sharing. I will owe you some credit for the successes that I will have racing this year!

  5. Hello…I have only spent a moment on your site…looks great!

    I did that chart for Carl in about 5 minutes…in a way that hopefully crossfitters could understand my impression of intensity…

    We all look at intensity in many different ways…and that really depends on the length of your event…

    In a mountain bike racers mind…I might say that all out is somewhere in the 90 to 120 minutes range…

    for a rower somewhere between 6 and 9 minutes…

    So the charts are great…including yours and mine as long as they are applied in a certain and appropriate manner…

    The reason I am not so fond of charts is because I really like to coach individuals…and everyday requires a new chart of intensity due to the stress situation of the athlete from sport and life…

    Keep up the great work…

    Steve Neal

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