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.

    Sunday, March 30, 2014

    Race Time Prediction

    This analysis had not been updated for nearly three years, so it was long overdue for an update. The list of events covered by the race time prediction analysis has now grown to include 49 events and/or distances. While the analysis was initially intended to focus on ultramarathons, it has expanded to include a wider range of trail and mountain running events, including multiple at sub-marathon distance. All recent variants of the Tarawera Ultramarathon. Five ultramarathons no longer held (or superseded by course changes) have been included for historical interest.

    Skip to prediction table Take me to the pictures

    The full list of events is:
    • Sub-marathon trail run:
      • Avalanche Peak Challenge (old distance);
      • The Hillary 34km;
      • Jumbo-Holdsworth Trail Race;
      • The Kaweka 36km;
      • Routeburn Classic;
      • Tararua Mountain Race (Southern Crossing);
      • Tararua Mountain Race (Kaitoke-Holdsworth).
    • Marathons:
      • DUAL Trail Marathon;
      • Motutapu Marathon;
      • New Plymouth Marathon (which is net downhill and fast);
      • Standard Marathon;
      • T42 Trail Marathon;
      • XTERRA Waihi Marathon.
    • Ultramarathons:
      • Reference* 50km, 80km, 100km;
      • Bedrock Ultramarathon;
      • Great Naseby Water Race 50km, 80km, 100km, 100 mile;
      • Hutt River Trail Ultramarathon 60km;
      • "Kaimai Killer" 60km;
      • The Kaweka 50km;
      • Kepler Challenge 60km;
      • Length of the Lake 67.5km;
      • Marton-Wanganui 67km;
      • Molesworth Run;
      • Northburn 100 mile;
      • Taranaki "Round the Mountain" 100 mile;
      • Tarawera normal course 60km, 85km, 100km;
      • Tarawera fire course 60km, 85km, 100km;
      • Tarawera cyclone course 60km, 72km;
      • Te Houtaewa Challenge 90 Mile Beach;
      • Triple Peaks 47km.
    • Ultramarathons no longer held:
      • Heaphy Five-O;
      • St James Ultra;
      • Tarawera 2009;
      • Taupo 100km pre-2009 (very hilly first 45km);
      • Taupo 100km 2 Lap (2009);
      • Taupo 100km 4 Lap (2010, 2011);
    * Note: 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.

    The methodology remains as described in my May 2010 post. One commenter on the 2011 analysis observed that the change in the rate of slow down from 1.197 (2010) to 1.120 (2011) was a significant change and that perhaps more data was required. We now have more data, a lot more data... 9,514 paired observations. The rate of slow down is derived from the latest analysis is 1.208, consistent with the 2010 estimate.

    Table 1: Race Time Prediction Multipliers, Ordered by Multiplier

    EventDistance (km)   Multiplier
    New Plymouth Marathon42.20.969
    Standard Marathon42.21.000
    Avalanche Peak261.059
    Motutapu Marathon42.21.196
    T42 Trail Marathon42.21.199
    Routeburn Classic381.226
    Reference 50k501.227
    Dual Trail Marathon42.21.309
    Hillary 34km341.347
    Naseby 50k501.422
    Triple Peaks471.598
    Hutt River Trail60.251.617
    Waihi Marathon42.21.656
    TMR: Kaitoke-Holdsworth401.792
    90 Mile Beach601.819
    Length of the Lake67.51.886
    Bedrock Ultramarathon521.925
    Kaweka 36km361.962
    Tararua Mountain Race351.990
    Kepler Challenge61.32.155
    Reference 80k802.165
    Tarawera Fire 60km602.184
    Tarawera 60km602.259
    Tarawera "Cyclone" 60km602.308
    Northburn 50km502.353
    Naseby 80k802.509
    Tarawera "Cyclone" 72km722.615
    Molesworth Run842.620
    Kaweka 50km502.649
    Kaimai Killer602.673
    St James Ultra67.22.689
    Heaphy Five-O78.42.767
    Reference 100k1002.835
    Taupo 4 Lap (2010)1002.908
    Tarawera 2009893.098
    Taupo 2 Lap (2009)1003.156
    Taupo pre-20091003.175
    Tarawera 87.5km87.53.184
    Naseby 100k1003.285
    Hillary Ultra803.349
    Tarawera Fire 85km853.403
    Tarawera 100km1003.654
    Tarawera Fire 100km1004.034
    Northburn 100km1005.605
    Taranaki Round the Mountain1605.781
    Naseby 100 mile1605.796
    Northburn 100 mile16011.055


    The table and slow down factor enables us to produce some comparisons of races of the same or similar distance. Charts are provided below for 50km, 60km, 100km, and 100 mile races. The blue bar is the marathon time multiplier that is due to the distance of the event. The red-brown bar is the additional multiplier due to the "difficulty" of the event, whether that is due to climb, technical surface, altitude, etc. Over the longer distances (100km, 100 mile) Northburn is clearly the most difficult event, but over the shorter distance of 50km the Kaweka is more difficult.


    Post a Comment