Hi,
I'd like to be able to use a data field to show how much progress I am making on a hill walk or run compared with the Naismith time for the route covered so far.
Background - Naismith's rule is quite a reliable way to estimate how long a route will take for a given distance and vertical elevation/ascent. The time in hours is usually calculated as the number of miles divided by three, and the number of vertical feet ascent in feet divided by 2000 (or number of kms divided by 5, and number of vertical metres ascent divided by 600). Academic work (eg Scarf (2006)) evidences the reliability of Naismith's rule. Though Scarf also suggests different ratios across different activities, for men and women, I only need the basic rule.
If I'm part way through a hiking route, it's useful to know if I'm on course to complete in the expected Naismith time or not (which I can calculate easily without using the watch, but there may be a way to calculate this when following a Navigation route, for which the watch will 'know' the distance and ascent for the route). If I'm hill running, it's even more useful: I know for example that I can usually complete a 20km hill race with 1000m elevation and easy running ground in good conditions in about 2 hrs 15, which is about 0.4 of the Naismith time. Longer routes I might only be able to sustain 0.5 or 0.55 of the Naismith time.
Requirement: So I'd like a simple field called 'Naismith %' or 'N factor' which calculates (Elapsed Time in hours / (Distance in miles divided by 3 + Ascent in feet divided by 2000) [or in metric, distance in km divided by 4.83 + Ascent in metres divided by 610). This doesn't need a whole app or a whole screen data field, just a simple field which I can use in any combination with other fields in different apps for hiking / running / trail running. To run on a Garmin Fenix 3 HR.
This Naismith factor would enable me to pace myself on longer hill running challenges where it's critical to pace the early stage of the race to avoid blowing up later on. It would make it easier to maintain consistent pace throughout the run in order to meet a set deadline (long challenges often have a 12hr or 24hr time limit). Obviously I can't just rely on time elapsed as a proportion of overall target time, because that doesn't take account of elevation which makes a big difference.
Can anyone help? There's a version out there for 100km race pace which is kind of doing the same thing but it doesn't take elevation into account. I'll happily make a small personal or charitable donation if someone can solve the problem. I would learn to code but I suspect it will be a long haul...
Many thanks,
Orlando.
Orlando.
