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Race Faster by Training Slower, with 2:28 Marathoner Josh Sambrook

By April 18, 2019May 20th, 20234 Comments
man running a marathon

“You don’t need speedwork. I can think of many examples of very quick runners who do effectively almost no speedwork” – Josh S

Josh Sambrook (Strava) is a 23 year old running coach and athlete from Leeds in the UK. He is working towards a BSc in Sports Science & Physiology. He ran his first marathon at the age of 17, and he has completed 12 marathons since. His current PB is 2h28min, which he ran in the Yorkshire Marathon 2018.

What fascinates me about his story is that he has ran very fast marathon race times, while training at low heart rate, with almost no speedwork. His average pace in his 2:28 marathon training was 4:47 min / km (7:42 min / miles), this pace is about 70% of his race pace. His unusual training method advocates a slow and steady training approach.

Josh is a running coach at JSET.run. A few years ago Josh came across a scientist named Giovanni Tanda. In 2011 this scientist developed an equation that he claimed could predict marathon performance to an accuracy of 4 minutes simply by knowing the runner’s average weekly mileage (in the eight weeks leading up to a race), and the average pace of these miles. The equation states that by understanding the relationship between weekly mileage and weekly pace, you can combine these two factors into a measure of training load. 

sub 3 hour marathon training chart
Example of the average daily pace (min /km) and training volume in km / day to reach a Sub 3 Hour marathon. Image from JSET.com

Based on these fundamentals, Josh developed the JSET training program with a unique point system. Each week you have a point target – a number of points you need to earn in order to achieve your race goal. In this conversation Josh shares his approach to training and racing, fasted running, marathon time predictions, and many tips for runners looking to improve. 

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Question of the day, what was one of your key takeaways from this conversation. Please let me know in the comments!



  • Josh’s background as a runner and triathlete [2:55]
  • His first marathon experience struggling at the Cambridge Marathon in 3 hours 24 minutes [4:00]
  • How Josh’s training changed after 5 marathons [5:20]
  • Josh used to train mostly at 150 beats per minute, now usually trains mostly in 130 to 140 HR [6:40]
  • Testing HR at end of hard 5k [7:33]
  • Josh’s racing strategy first 1/2 166 bpm, then let it rise by 1 beat per minute per km [8:32] 
  • Josh increased his training volume by almost 10 fold in past 5 years at much slower pace [9:32]
  • How and why Josh runs two to three times a day, shorter distances [11:50]
  • The best predicting Marathon prediction times [14:05]
  • How lifestyle factors play a bigger impact on marathon performance for runners slower than 3:30 marathon times [17:50]
  • Tanda race predictor [18:55]
  • Josh developed a marathon coaching business based on running data points [19:50]
  • Josh’s thoughts on  Sub 3 Hour marathon approach, different distance and pace approaches for the same results [22:08]
  • Example Sub 3 marathon schedule with daily distance and pace [25:40] 
  • Importance of listening to the body to limit injury risk [27:35]
  • How cross training impacts running performance for different marathoners [29:20]
  • Find out what limits your race performance and work on this [30:08]
  • The recovery changes in different [31:40]
  • Josh’s thoughts on strength training for improving running performance [32:55]
  • Identifying limiting factors by learning from races [34:48]
  • You don’t need speedwork to become a faster runner [36:40]
  • How Josh training for his 2:28 marathon with only 5km at week at higher heart rate [37:00]
  • Seeing how people improve from 5 hour marathoners to 3:10 marathoners with no speedwork [38:44]
  • Longer term steady progress vs short spikes of progress [39:32]
  • How Josh motivates himself to train consistently in often bad UK weather conditions [41:45]  
  • Daily goals reminders easily viewable to stay focused [43:31]
  • Running by heart rate and by feel [45:05]
  • Accuracy of optical heart rate monitor vs HR chest strap [46:20]
  • Nutrition and fasted runs to improve your fat burning system [47:50]
  • Why Josh doesn’t take any calories during his marathon races [50:05]
  • Initial experiences with fasted [52:00]
  • What Josh eats after his fasted runs [52:50] 
  • How to record your workouts to improve your running [55:10]

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  • Nick Donaldson says:

    Very interesting episode! That graph is pretty cool. Another great episode! Thanks Floris!

  • john Harding says:

    Thanks Floris – Very interesting, really relevant to where I’m at – started digging into this a bit more now.

  • Joe says:

    Your math is off up there. A 2:28 marathon would be approximately 5:39 min/mile.

  • Joe says:

    Sorry, disregard my previous comment. I don’t think I can edit or delete it. I read it wrong above. My bag.

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