Science based training
Tailored to you
Adapting to your progress
Giving you the confidence* to succeed
*and fitness

Every JSET training plan is unique, specific to your:


Down to the minute. If you're chasing a 2h57min marathon then a sub3 plan isn't right for you, you need a 2h57min training plan.


Busy job? No problem, we'll work around it. Getting a PB doesn't have to take over your life.​


JSET looks at your previous race performance and your training history. By comparing these it can assess how your body responds to training.

Training preferences

Let's do the type of running you enjoy. If you love running at a "chatting pace" with friends then do that. JSET tells you exactly how much "chatting pace" running you need to do.

Current ability

Everyone is starting from a different place, so even two runners who have the same goal need different programs. JSET accounts for that.

(it'll also adapt)

JSET adapts according to how well your training is going. Say hello to overachieving!

JSET is a highly personalised running training system which takes the uncertainty out of your racing by using science, rather than guesswork, to plan your training and assess your fitness. By understanding the relationship between average pace, weekly distance and performance, JSET enables runners to do more of the training they enjoy and gives runners confidence that they’ve got the fitness to achieve their goal.

By assessing your recent training JSET is able to set out a challenging, yet achievable, training goal each week. The JSET dashboard will always push you to improve, working towards your race or fitness goal. In this way the JSET dashboard is designed to keep you progressing and motivated each week.

Coupled with coaching and extra analysis from Josh Sambrook, an accomplished marathon runner, JSET has helped athletes across the globe, of a wide variety of abilities and backgrounds, achieve their running goals. From runners who simply want to finish their first marathon to runners aiming to win races, JSET works for everyone.

By signing up for an online training plan with JSET, you will receive a training plan, personalised according to your goals, past performances, current ability, lifestyle and training preferences. This gives your training a high degree of specificity, so you will not feel like you’re following a generic plan.

A JSET training plan can change the way you train. Each week you have a target training doughnut. This is simply the training load you need to run in order to achieve your race or fitness goal. Each mile you run moves you towards this target, and running faster counts as more of your training load. Click on the blue doughnut to learn more. 

It’s up to you to decide how you train. Some people run big distances every day, at a consistent, slow place. If you’d rather run a coached session with a club that’s fine too – just make sure you run enough each week to meet the training load target. It is this highly individual training that has helped runners of all abilities improve.

If you stick to the JSET training program you can be confident you’ll be fit enough to achieve your race or fitness goal. You’ve got the experience of me, an accomplished marathon runner, but it’s the science behind the unique training program that’s the really special thing about JSET.

Josh S is the coach behind JSET

I believe almost anyone can be a fast runner if they do the right training. In 2016 I was directed towards the equation that JSET is based on, and by applying it to my training I found I was getting faster and faster. By the end of 2018 I was the fastest U23 marathon runner in the UK. This isn’t because I’m naturally a fantastic runner – for a long time I was an average runner, finishing as an “also ran” in cross country and marathons.

It was training correctly, in a way that I enjoy, that enabled me to really improve. JSET training uses the structure of science, combined with the intelligence of a skilled human to generate a training program that allows athletes to achieve more than they thought possible. JSET is different because the science underpinning the program understands exactly what training load your body has experienced, and what race performance that will produce.

My training methods are unusual, but have resulted in significant progress for all kinds of people. Essentially, my own training involves running big weekly distances at an easy pace. At the peak of a training cycle I run over 250km per week. One particularly unusual element of the training is that it doesn’t involve running anywhere near race pace for the vast majority of the training. Find out more about the training style.

And finally, some background about me

I am a graduate of the University of Leeds, with a BSc in Sports Science & Physiology. For my final year project (dissertation) I investigated predicting marathon performance from training variables and previous race performance; this is the work that I now use as the foundation of JSET. I ran my first marathon at the age of 17, and I’ve run at least one every year since. My current PB is 2h28min, which I ran in the Yorkshire Marathon 2018.

I’m happiest when running; whether racing or training, alone or with friends, in sunshine or rain.