Race Equivalency Chart

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The race equivalency chart uses your recent race performance in a distance and converts that time into predicted finishing times at other race distances.  It's important to note at the onset that the predicted values from this chart assume the races are under similar conditions.  So if your recent 10k race was cold, flat, and straight, but your upcoming marathon is hot, hilly, and lots of curves, then your marathon race equivalent is going to be likely a bad predictor.  The race equivalency will say you'll run a time of X, but you're likely to run slower than X.

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The formula for the race equivalency chart is from Peter Riegel's paper "Athletic Records and Human Endurance" American Scientist May-June 1981.

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t2 = t1 * (d2 / d1) ^ 1.06

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t2 = upcoming race time (or predicted time)

t1 = recent race time (like inputted in the above Excel file)

d2 = upcoming race distance

d1 = recent race distance (like chosen from drop down in above Excel file)

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The exponent value of 1.06 was found to be a "fatigue factor" that would adjust the predicted pace as the distance increased.  A runner wouldn't simply double their half marathon time to predict their marathon time.  Rather using an adjustment of an exponential increase of 1.06 would yield a more accurate prediction.

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For the purposes of this calculator, I have decided to use an exponent of 1.07-1.08 for distances between 1500m and 3k.  Additionally, all other distances from 5k to 50k use an exponent of 1.06.

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Predicted Range of Marathon Performance under Similar Conditions to Recent Race

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The dataset of runners running road races in 1981 has changed from the dataset of runners running in present day.  While many endurance distances still hold using the Peter Riegel formula, the marathon tends to be a distance a classic race equivalency calculator over-predicts (too fast a prediction).

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Two recent papers/articles suggest an "average" conversion of a marathon performance from a half marathon to be a 1.15 exponent instead of a 1.06.  Those papers/articles were.

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Vickers and Vertosick. "An empirical study of race times in recreational endurance runners"​. BMC Sports Science, Medicine and Rehabilitation. 2016 8:26

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Williams. "An updated formula for marathon running success". The Guardian. 2018/2/15 (link)

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Each of these papers contained a data set which when plotted out based on a conversion of half marathon performance to marathon performance, showed the average marathon runner performance around a 1.15 instead of a 1.06 for an exponential value.  See this blog post (Ian Williams: An updated formula for marathon-running success) for my analysis of the paper as well as a run-down of what makes someone a "good converter".

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So, this calculator provides four predicted values:

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Aggressive = which is the Peter Riegel exponent of 1.06

Blaser High End = which uses an exponent of 1.07.  I find most of my training plans yield a value as high as 1.06-1.07

Blaser Low End = which uses an exponent of 1.10.  I find most of my training plans yield a value no lower than 1.10.

Average = which uses an exponent of 1.15 and is based on the Williams and Vickers datasets.

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So for the purposes of training, I suggest using the "aggressive" value as this represents close to the physiological aerobic threshold and yields the benefits desired at this pace.  But for the purpose of racing, keep in mind actual performance is more likely to be in the range of the "Blaser High End" to "Blaser Low End" for my training plans.  Use a training plan that doesn't adhere as close to the "good converter" ideas, and you'll be closer to 1.15.

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Again, important to note that this calculator assumes the recent race (used as input) is under similar conditions to the predicted race.

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Continuous Runner Training Paces

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Continuous runner training paces are based on the relative relationship between marathon pace (aerobic threshold) and other physiologically relevant paces.  The relatively "easier" paces range from 9-20% slower than marathon pace.  The half marathon, 10k, 5k, 3k, and 1 mile paces are based on the race equivalency chart.  The lactate threshold pace is based on an estimated value for 60 min race pace (or said another way, what is the pace you could hold in a 60 min time trial).

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When following a Blaser Coaching Services training plan, in general 80% of your training will be at the "Long Run" pace or slower.  Only 20% of your training will be at marathon pace or faster.  As the saying goes, "Train slow to race fast".

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Run/Walk Training Paces

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This calculator uses a method of physiologically relevant pacing combined with the run/walk style.  It's an attempt at developing a calculator that will suggest pacing schemes for you based on different training paces.  To use this calculator, make sure the yellow box for "comfortable walking pace" has been inputted in a HH:MM:SS format (such as 0:17:00 for 17 minute/mile walking pace).  As you can see, the walking pace is fixed at your set value for a comfortable walk.  The duration of the walk is also fixed at 30 seconds.  The run pace is fixed based on the different paces themselves.  Lastly, the run duration is calculated using the formula:

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((Walking Pace - Average Pace)*Walking Duration) / (Average Pace - Run Pace) = Run Duration

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The output are 5 paces that can used in training.  There are two different versions of this calculator based on the style of run/walk someone desires.

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Option A = Slower run pace, but with longer run duration

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Easy/Long = 80% of training would be at this pace.  The basis is to keep this pace truly easy and mostly for building fatigue from one run to the next.  In keeping with this philosophy, I set the run pace to be at the "long run" continuous pace as to elicit the desired nearly 100% easy aerobic pacing.

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Marathon = The run pace on this interval set is the "LT" pace.  This is the estimated lactate threshold pace for the runner (estimated 60 min race pace).  The normal run to rest ratio is 5:1 for LT pace in a training workout.

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Half-Marathon = The run pace on this interval set is the "5k" pace.

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10k = The run pace on this interval set is the "3k" pace.  This pace is very close to a VO2max training pace.  Ideally, the run duration of this pace is kept between 2-5 min with equal rest.  But keeping the run duration to less than 2 min is ideal.  The normal run to rest ratio is 1:1 in a training run.

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5k = The run pace on this interval set is the "Mile" pace.  Ideally, the run duration of this pace is kept to less than 2 minutes.  The normal run to rest ratio of mile pace in a training workout is 1:2-3.

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Option B = Faster run pace and a shorter run duration

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Easy/Long = 80% of training would be at this pace.  The basis is to keep this pace truly easy and mostly for building fatigue from one run to the next.  In keeping with this philosophy, I set the run pace to be at the "long run" continuous pace as to elicit the desired nearly 100% easy aerobic pacing.

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Marathon, Half-Marathon, and 10k = The run pace on this interval set is the "3k" pace.  This pace is very close to a VO2max training pace.  Ideally, the run duration of this pace is kept between 2-5 min with equal rest.  But keeping the run duration to less than 2 min is ideal.  The normal run to rest ratio is 1:1 in a training run.

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5k = The run pace on this interval set is the "Mile" pace.  Ideally, the run duration of this pace is kept to less than 2 minutes.  The normal run to rest ratio of mile pace in a training workout is 1:2-3.

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Continuous Runner Training Paces: Temperature + Dew Point Adjustments

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As described above, the race equivalency chart and training pace calculators are based on the "recent race" being under similar conditions to the "predicted race".  In most cases, the temperature and dew point (T+D) of the recent race isn't going to be the same as all of the training days.  So this chart helps give a general idea as to how to adjust paces based on different conditions. 

 

So to use this chart, look at the training pace you are scheduled at for the day's workout.  Then check the current temperature and dew point for the beginning and end of the workout (I personally use weather underground which has this information easily accessible).  Add those two values together (for example, temperature of 70 and dew point of 65 is a T+D of 135).  This helps set a general idea as to how you should adjust your pacing goals for the day. 

 

This system isn't perfect.  It's a nice way to get a general idea as to how to adjust.  But as I always say, think more about the paces as a general goal for the day.  The gold standard is effort.  So if effort says, go slower, then go slower.  If effort says go faster, then in most situations, pull back and maintain the T+D adjusted pace.  And when it comes to easy - "easy isn't easy when it doesn't feel easy".

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The basis of this calculator comes from the following site:

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http://maximumperformancerunning.blogspot.com/2013/07/temperature-dew-point.html

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Run/Walk Training Paces: Temperature + Dew Point Adjustments

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See the above post about continuous runner training paces temperature and dew point adjustments as all of that information is relevant to this chart as well.

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Additionally, in order to achieve a slower average run/walk pace, I suggest maintaining the interval duration (like 60/30 or 30/30, or whatever it is) and maintaining your normal comfortable walking pace.  So the only variable that should be manipulated is the run pace.  Slow down the run pace of the run/walk to achieve the slower average pace.  As with the suggestion in the continuous runner adjustments, pay attention to effort.  If effort says run slower, then run slower.  But in general, if effort says run faster, then I suggest maintaining the T+D adjusted pace.

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Sources​

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Riegel PS. Athletic records and human endurance. Am Sci. 1981 May-Jun;69(3):285-90. PubMed PMID: 7235349.

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Vickers and Vertosick. "An empirical study of race times in recreational endurance runners"​. BMC Sports Science, Medicine and Rehabilitation. 2016 8:26

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Williams. "An updated formula for marathon running success". The Guardian. 2018/2/15 (link)

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Hadley, M. Maximum Performance Running. Accessed 2018/08/26. http://maximumperformancerunning.blogspot.com/2013/07/temperature-dew-point.html

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