On the subject of PRs

We’ve been getting a lot of questions about the PR (personal record) section of Smashrun recently, and as they come up I’ve begun to think a lot about the way I’ve implemented it and the pros and cons of the approach.

The PR section on Smashrun is pretty straight forward. I take the speed you ran and then for any run just equal to or farther than a common PR distance for the unit (km/mi) you’ve selected and I multiply the speed by the rounded distance.

An example should make this clear:

You run 10.5k in 1 hour.

So your speed is 10.5k per hour.

Running at 10.5k/hr for 10k would take only 57 mins and 8 secs.

So I use 57:08 as your PR, that way you’re not penalized for running a bit farther. The idea that something would have been a PR if only you stopped at exactly 10k just seems silly to me.

What’s good about this is that you can compare every about a 10k with every other about a 10k. I find this great because usually I just walk out my door and run, and only stop when I get home – I’m not about to start walking just because my GPS says I’ve hit exactly 10k.

Ah, but, how about if you’re in a race? Every course is different, and every racing line is different. I’ve run 10k’s that are curvy and crowded and my GPS has registered well over 10k. I think most people feel that your time is your time for a race. Your 26.6 mile marathon at 4:01:00 isn’t a sub four just because you made wide turns, right?

But at present Smashrun doesn’t this work this way. Whether a run is tagged as race or not. Your PR is the run where you ran the fastest. Period. If you ran 10.5kph on average for a 10k race that your wide turns turned into a 10.5k race. Smashrun will say that that’s faster than a race where you ran 10.1kph on a pretty straight line for exactly 10k.

So, I’m considering having two models. For races your time will be your time, but for all other runs your time will continue to be calculated as it is. But before I make this change we wanted to get your thoughts.

What makes the most sense?

Do you have any better ideas on how to handle this?


Jay Pantone

I ran a 10k yesterday, but the first 5k of that run was faster than my previous 5k PR, so Nike+ counts that as my new fastest 5k on the “Records” tab. However, it doesn’t seem like Smashrun counts it as a 5k PR because when you average out the time for the whole run, it was a slower pace than the previous 5k PR. Why can’t Smashrun just truncate the run at the first 5k (or, in your example 10k), and take the time from that?


We could absolutely do that. In fact what we could do is take any embedded 5k and call that a PR, so if you ran a 10k and 4.5 – 9.5k was your fastest 5k ever that could be a new PR. But I guess the question is would that be confusing? Would you really consider it a PR for example if say you run a 10k and the first half is up a hill and the second half is back down and the 5k down was your fastest 5k ever?

Jay Pantone

That’s a great point. We don’t have hills here in Florida, so that never even occurred to me. I guess the way it’s done now is fair, I just didn’t understand how it worked until I read this post, especially since the statistics here didn’t agree with the statistics on Nike+.

As for the change regarding races vs. non-races, I think what you’ve proposed makes sense, as long as it’s explained somewhere to keep people like me from getting too confused!


I like the idea of taking the PR out of any of the distances and putting as PR. The option to sort by race tags that exists would allow you to have “race PRs” and other fastest distances. Right now (since I ran a 1.86 mile run which got rounded down) I only have one 1 mile run which has PR of 8:42. My 4 mile run, however, is at average of 6:33 per mile which I would personally like to see as my 1 mile record. Just my thoughts, since I don’t feel like running a 1 mile race against myself!


sounds good! thanks for taking the time to think about all this. I like the idea of calculating my PRs no matter how long I run. I dont really get why someone would care about inaccurate race courses or wide turns or whatever, but as long as there is an option for either method, it works for me.


I like what you have proposed, keeping two sets of PRs, one for races and the other for all other runs. Thanks for asking!


I like the idea of being able to tag a race as “chip timed” or something to that effect and being able to specify the distance of the run.

A feature that would be useful as well is if we could see a graph that over laps your top times in the 3K / 5K / 10K etc. I’m a beginner and it would be useful to be able to see my pacing on various 3K’s all at once… not sure if I am explaining this correctly.

Marcel Gort

Thanks for listening to user feedback!

The most useful thing for me would be what Jay Pantone suggested. I start and finish every run with slow running so my smashrun PRs are all worse than they should be. I understand the difficulty with hills and counting a large downhill section as a PR wouldn’t be right, but perhaps you could check if the elevation drop for a subsection of a run is similar to the elevation drop for the entire run, in which case the subsection could be counted as a PR.

Michel Kok

Good idea, I like both parts: (1) a subsection of a run should be a PR and (2) but only after an elevation check (to prevent downhill-only records).


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