Note that the original formula uses a value of 1.06 while a value of 1.15 has been proven to be far more accurate for most people; this is due to the fact that 1.06 has been found to be a "highly optimistic" value to use just as 1.15 has been found to be more realistic. Riegel's formula has its limits like any other formula and thats why alternatives like the Dave Cameron Model exist; it's more useful when concerning ranges of 800m to 10km. I'll be uploading a PDF later of the exact formulas on my site. Look for it right underneath this post referral on my site map. Anyways, here's a calculator I made today to use and offer to you all.

For the sake of Clarity, While I do use the Riegel formula in the spreadsheet, The RunSmart Project calculators do NOT. They in fact use a rather complex set of formulas developed by Jack Daniels' and Jimmy Gilbert back in the 70s. While they are vastly different approaches, they do produce fairly similar results. Riegel's formula does start to falter below 5k. Both formulas are quite accurate when looking at Elite times. However, as you get farther away from the elite athlete, it is less likely that intermediate runners do adequate training for the longer distances, and I suspect this may be why the suggested Riegel value of 1.15 works better for them.

Hello I actually did deduce that problem you spoke of. I should've noted that your SPD used the RF specifically. My fault! Anyways I did find that problem you spoke of. IMO it's not very deep math, it's just that it's not a formula, rather a tedious iterative process (such as using Newton's Method 2+ times). I was rather saddened that they do this but oh well can't help it when engineers do this kind of stuff as iterative methodologies are their go-to's.

Besides the points you laid out I'm glad you at least saw my post!

Hi, I'm the author of the spreadsheet you link above at http://www.electricblues.com/html/runpro.html, and I'm a huge fan of Jack Daniels' training philosophies.

For the sake of Clarity, While I do use the Riegel formula in the spreadsheet, The RunSmart Project calculators do NOT. They in fact use a rather complex set of formulas developed by Jack Daniels' and Jimmy Gilbert back in the 70s. While they are vastly different approaches, they do produce fairly similar results. Riegel's formula does start to falter below 5k. Both formulas are quite accurate when looking at Elite times. However, as you get farther away from the elite athlete, it is less likely that intermediate runners do adequate training for the longer distances, and I suspect this may be why the suggested Riegel value of 1.15 works better for them.

If you're interested in learning more about Jack Daniels' formulas, you can find info at:

http://www.simpsonassociatesinc.com/runningmath1.htm

But I warn you, it involves some very deep math.

regards,

Herm

Hello I actually did deduce that problem you spoke of. I should've noted that your SPD used the RF specifically. My fault! Anyways I did find that problem you spoke of. IMO it's not very deep math, it's just that it's not a formula, rather a tedious iterative process (such as using Newton's Method 2+ times). I was rather saddened that they do this but oh well can't help it when engineers do this kind of stuff as iterative methodologies are their go-to's.

Besides the points you laid out I'm glad you at least saw my post!