Welcome to my blog. The title originates when my primary athletic activity was competitive walking, but now that I am back to running it also includes that.

Not all content is accessible from the main page: for example, the rogaines, racewalking, and ultramarathon pages all include content that is only accessible from those pages.


Ultramarathons are any event longer than the standard marathon distance of 26.2 miles / 42.195km. Standard distances for ultras are 50km, 50 miles, 100km, and 100 miles. There are also 12 hour and 24 hour track runs, and multi-day "stage races".

I have currently (September 2012) completed 30 ultramarathons, plus 1 DNF at about 66km at the Molesworth Run. Reports for most events are provided below.

See also


Rogaining is the sport of long distance cross-country navigation. Events can be as short as 2-3 hours or the standard 24 hours. Teamwork, endurance, competition and an appreciation for the natural environment are features of the sport. Rogaining involves both route planning and navigation between checkpoints using a variety of map types.

GN Phillips and RJ Phillips, Rogaining, 3rd ed, 2000

The two main umbrella organisations for rogaining in New Zealand are: My reports for selected events are provided below.

Hiking and Mountains

The Hiking, Trail Running, and Mountains pages are all inter-related, but with some subtle differences:
  • Hiking is not an organised race, and may include Coastal Adventures, activities in the Mountains, and hiking in other locations;
  • Trail Running covers organised events, some in the mountains, but others on local hills and trails; and
  • The Mountains category covers both events and hiking in various places that can be classed as mountains.

  • Racewalking

    Racewalking only has to meet two technical requirements:
    • no loss of contact, as judged by the human eye; and
    • the leg has to be straight from the moment of first contact until it is upright.
    More detailed rules are here.

    I'm not particularly good at racewalking, often falling foul of the straight leg rule. But I still give it a go and here are the results of my endeavours.


    This blog is primarily about my walking activities, but sometimes I do run. Here are reports for events where I have run.

    Shorter Races

    I classify events as ultramarathons, marathons, rogaines, and "shorter events". So a "shorter event" is just something that is shorter than a marathon and is not a rogaine. Consequently there's a mixed bag in here: running, racewalking, half marathons, 10k and 5k races, , etc.

    Monday, April 11, 2011

    Updated Race Time Prediction

    The list of events covered by the race time prediction analysis has now grown to include 29 events and/or distances. While the analysis is focussed on ultramarathons, three trail marathons are now included, as is the sub-marathon Routeburn Classic. The new Northburn 100 mile run is included, but the shorter Northburn events (50km and 100km) have insufficient finishers to be included in the analysis. Five ultramarathons no longer held (or superseded by course changes) have been included for historical interest.

    The full list of events and distances is:
    • Sub-marathon trail run:
      • Routeburn Classic
    • Marathons:
      • DUAL Trail Marathon;
      • Motutapu Marathon;
      • New Plymouth Marathon (which is net downhill and fast);
      • Standard Marathon;
      • T42 Trail Marathon;
    • Ultramarathons:
      • Reference 50km, 80km, 100km;
      • Great Naseby Water Race 50km, 80km, 100km;
      • Heaphy Five-O (no longer held);
      • Hutt River Trail Ultramarathon 60km;
      • Kepler Challenge 60km;
      • Length of the Lake 67.5km;
      • Marton-Wanganui 67km;
      • Molesworth Run;
      • Northburn 100 mile;
      • St James Ultra (no longer held);
      • Tarawera 2009;
      • Tarawera 60km, 85km, 100km;
      • Taupo 100km pre-2009 (very hilly first 45km);
      • Taupo 100km 2 Lap (2009);
      • Taupo 100km 4 Lap (2010, 2011);
      • Te Houtaewa 90 Mile Beach Run;
      • Triple Peaks 47km.
    The Sri Chinmoy 50km and 100km events (Christchurch) are counted as "reference" 50km and 100km events due to the flat, fast nature of the course.

    The updated table of multipliers is given below.

    Table 1: Race Time Prediction Multipliers, Ordered by Multiplier

    EventDistance (km)   Multiplier
    New Plymouth Marathon42.1950.96
    Standard Marathon42.1951.00
    T42 Trail Marathon42.1951.17
    Motutapu Marathon42.1951.19
    Reference 50km501.21
    Routeburn Classic381.24
    Dual Trail Marathon42.1951.31
    Naseby 50km50.11.41
    Triple Peaks471.59
    Hutt River Trail60.251.62
    Te Houtaewa 90 Mile Beach601.81
    Length of the Lake67.51.94
    Reference 80km802.05
    Kepler Challenge61.32.16
    Tarawera 60km602.26
    Naseby 80k80.162.39
    Molesworth Run842.58
    Reference 100k1002.63
    St James Ultra67.22.66
    Heaphy Five-O78.42.74
    Taupo 100km 4 Lap (2010, 2011)1002.86
    Tarawera 86km863.07
    Naseby 100km100.23.07
    Tarawera 2009
    Taupo 100km pre-20091003.12
    Taupo 100km 2 Lap (2009)1003.13
    Tarawera 100km1003.64
    Northburn 100 mile1609.52
    Note:(*) Although the precise distance for the 2009 edition of the Tarawera Ultramarathon is unknown, this does not affect the overall multiplier.

    The methodology remains as described in my May 2010 post. The rate of slow down derived from my latest analysis is 1.120, rather than the 1.197 previously obtained.


    Philip Sharp said...

    Hi Andrew:

    I think the change in the exponent from 1.197 to 1.120 is significant. The change suggests to me that the data set for the first estimate (1.197) was not large enough. Two questions come to mind:

    1. How much do you think the 1.120 would change if you had a lot more data?

    2. Have you considered applying your analysis to more homogeneous sets of events. For example, track events or track and flat loop events (such as 100K in Hagley Park)?

    Best wishes.

    NZ Centurions

    Andrew Shelley said...

    Hi Philip

    It has taken a long while (2.5 years since your comment), but the analysis has now been updated. There is now considerably more data (9,514 data pairs), and the exponent has returned to 1.20.

    The track and flat loop events are critical for the exponent, but we really don't get enough people doing them. My analysis relies on having the same person competing at different distances/events over a relatively narrow time period (4 years), but unfortunately the flat events don't attract he entrants.



    Andrew Shelley said...

    I should have also added, the output of the new analysis is available on this blog at

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