Talbot's Rule

The elevation profile of the Malvern Hills Trail Race

During the Covid-19 pandemic  virtual running races have become popular. Such races give participants the opportunity to plan and run their own course from their home, running a set horizontal distance (for example 10km). As such each participant would be running a different route with varying amounts of height gain, over the same horizontal distance, whilst adhering to the social distancing guidelines.

In April 2020 Dave Talbot, an adventure specialist from Bristol, devised a simple method to help calculate fair results so that they reflected each respective height gain by subtracting 1 minute for every 25m of height gain. On a bigger scale: subtract 4 minutes for every 100m of height gain.

Dave shared his initial tests with myself, I then derived this formula based on Dave's initial predictions and testing:

TT = CT - (2.4 x HG) / 60

where:

TT = Talbot Time (minutes)
CT = Clock Time (minutes)
HG = Height Gain (metres)

As in walking (Naismith's Rule) there are variables such as terrain and amount of kit carried.
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We are now testing this formula on a number of virtual races during the Covid-19 pandemic, initially we are looking at distances of 10km to 21.1km. These virtual races provide focus, motivation and fun to runners all over the world.