The Runners

In addition to the fuller profiles set out below, which span much of the time I've been coaching with a focus on recent and long term high achievers....

Runners I coach took 5 places in the Top 75 men in the London Marathon field in 2018 - which was as ever the National Championships, including the first UK man over 40.

In 2019 this London Marathon stat became 6 in the Top 100, with 4 of these setting PBs in the range of 2.24 to 2.30. 

In the year to January 2024 four runners I coach have clocked marathon PBs of 2.15, 2.22, 2.23 and 2.24 and all being well a further three guys aim to join the sub 2.30 crew this spring.

Since August 2023 I have been coaching Jacob A, a talented and proven international level athlete. Highlights over this period included an outstanding 47.13 to place 2nd in the Great South 10 miles, a big PB of 63.18 at the Barcelona Half Marathon, and a PB 10k of 28.44 in Valencia, where running for Team England he finished just ahead of the dazzling new women's world record performance

From mid 2017 to 2020, Izzy C joined the crew and she set Serpentine club records at numerous distances, highlights being the 5k road in 16.43, 34.34 on the track at 10,000 in 2018, 76.29 PB at the Cardiff Half where she placed 19th in the Commonwealth Championships incorporated, and 5th place in the National 10,000m championships.

For those interested in pace below Marathons, and we all should be, in recent years I have coached 11 runners in 14 minute 5000m territory (three of whom went sub 14 by some margin). 5000m is the distance where 'long distance running' officially starts 

From 2017-19 I coached Christine K, an extraordinary V60 runner and twice, at her peak in the 1990s, Dublin Marathon winner with a 2.35 PB. She is the oldest woman ever (at 59) to have broken 3.00 for a marathon and recently won the World Masters half Marathon in Spain by over two minutes (94 mins in 27 celcius, for a 63 year old women seems swift to me!), backed up by silver in the 5000m. She pushed on again at the San Sebastian Half Marathon 90.23. As context, if this had taken place 4 weeks later, she'd have equalled the World Best for a 64 year old.  

From 2016 to 2020 I coached leading BBC broadcaster Sophie Raworth to numerous PBs at 10k, half (94) and full marathon (3.27, with recent PBs at age 51 and selection to run for the England Masters in a Home Countries International at Half Marathon. 

Alex LeP, 30, London

I started working with David ahead of my first attempt at the marathon, London 2023. At that stage I felt I was able to self-coach for the distances I was currently racing, from 5k up to the half-marathon, through a mixture of attending the club sessions with Highgate Harriers and my own experience. To train for a marathon, however, I thought needed a different approach but was outside my own experience and so I asked David to structure a personalised training plan for me. 

The initial target for London 2023 was to run 2:15. While a little ambitious for a first attempt, it was also something I thought I was capable of achieving with the right training. However, by the time I came to line up on the start line, a minute or two quicker seemed possible. David's coaching, his experience and wealth of knowledge of the sport all contributed to convert my fitness at the shorter distances into marathon fitness, setting a plan for me that was challenging but achievable.  The sessions that he sets are always engaging and clear in what they are trying to achieve. David also helped advise me on everything around the actual running as well, from nutrition strategies to the benefits of heat training.  In the end I ran 2:15:01 (although with some slightly better pacing in the first half, I may have been able run that minute or two quicker). 

A year later and I'm still working with David, not just for the marathon, but all distances. Having someone with David's skill in your corner is invaluable. 

Alex had already run sub 63.30 at half marathon and sub 29 for 10k when we started the link. Since then in addition to the fine London Marathon debut (2nd finisher with a day job!) he has also set a 5000m PB and ran 2nd fastest leg at the prestigious National 12 stage road relay, and come 2nd, twice, in the Southern X Country championships.

Will,  now 47, London                       
I started coaching with Dave in November 2009 after a disappointing and painful New York marathon.  I had run at club level at school and after long absence returned to running entering the London and then the New York Marathon.  At the time of New York, my running career seemed to have reached a dead end.  Since then, well, my results have been, from my perspective, fantastic - I cannot speak highly enough of Dave as a coach and the transformation he has brought about to my running career.

Dave has an encyclopaedic knowledge of "how to" train and race effectively and his approach to training encompasses all aspects - from the training itself (and recovery), to running form and technique, diet, strength and conditioning etc.  Over the last 10 years I have become a better and stronger athlete, my running technique has improved, and racing performances have improved markedly as a result. 

Dave's coaching programme is extremely well tuned to what you can achieve as an athlete- it is hard, challenging and varied however always conscious of overtraining, and the need when training at high intensity to get "more out of less".  I am always surprised how Dave can judge where an athlete is in terms of performance - from directing the training pace in a series of intervals, to predicting race performance. To my mind, it is a sign of his experience and knowledge that he always knows the level at which I should be pushing to achieve, and when to push it harder and when to ease off.  It is also a sign for how much he understands the athletes he trains and how much attention he pays to them. Dave also clearly understands the demands of running whilst also holding down a full time job and the limitations this can place on recovery and he has tailored his advice to me to take this into account.

Dave's technical knowledge of the physiology of running is impressive and comprehensive - for every session there is a reason for why the session is being ran, what the session is trying to achieve physiologically and how that transforms itself into better racing.  I have found that Dave builds the same methodology into his overall training cycles, so I have confidence in working towards long term goals.  Dave’s advice is distilled into practical, easy to understand methods and reasoning – always honest and to the point, and with a sense of humour and appreciation for everything else that goes on in life. In 2014, coming up to his 40th birthday, Will ran perhaps his best race thus far at the Leeds Abbey Dash  clocking 31.17, one of the leading UK10k marks in his age group. In 2018 Will, now 43, made even further progress, with PBs at Half Marathon of 68.16, 3rd across the UK V40s, and at London ran a super PB of 2.27.02 to be the first UK V40 in the entire field, In May he completed a great London triple, a PB of 31.15 in the Vitality 10k, just pipped for first V40 in the UK Championship race. December's Valencia Marathon brought another career highlight where, 2 days before turning 44, Will ran 2.24.47, ranking him 2nd in the UK rankings for 40+ for 2018. Will is greedy in the most admirable focused way and so London 2019 nudged forward his PB to 2.24.18, 2nd UK V40 beaten only by a man barely out of his 30s! In June he raced in the prestigous England National Track Champs at 10.000 and excelled again with 31.05. His outstanding 2019 continued with a win at the famous Highgate Night of the 10,000s, another PB of 30.50; with tremendous progress at 5000, clocking 14.48 at Milton Keynes and then a mighty 14.35 at Wimbledon, the FASTEST ALL TIME by a UK runner of 44 or older.And the year ended with a mighty 67.47 at the Cardiff Half and a tremendous 30.30 at the Telford 10k, significantly just a few days after his 45th birthday - placing WIll 4th on the UK All Time lists for this event. March 1 at the Big Half Will stepped up again,67.13 a PB and a stunning 3rd on the UK All Time lists for 45+. With a Covid-driven racing lull over 2020, Will returned again with a fantastic PB of 2.24.11 at the Cheshire Elite Marathon in April 2021, aged 46 and again in the Top 5 marathons ever by UK runners in the V45 category. Keeping his racing schedule light but meaningful, WIll placed second in the notorious Sevn Sisters/Beachy Head Marathon in October, then on the undulating Brighton Marathon course in April 2022, now in his 48th year, he placed a close 3rd, on 2.30.02

Paul, 41, London

"I started my coaching journey with David in 2017. Prior to approaching David, my times had plateaued, and I was keen to see if a Coach could help me get my times down further. Since being coached with David I have taken notable chunks off all my PB's at every distance from 5k to the Marathon.  David's coaching knowledge, built up over many years' experience is as comprehensive as you can find in the running sphere.  David's coaching style is refreshingly straight forward and easy to follow. Feedback and communication is thorough and well thought out. David has also written a couple excellent books on distance running. I cannot recommend David's services more highly." 
Paul Piper 
2.23 Marathoner. 

Paul came to me with a few years of very high mileage and a 2.28 PB and the statement that "at this stage I expect PBs to come in seconds not minutes, as he was close to plateauing. My view was that the onslaught of mileage, around his shift pattern at London Heathrow, was worth reviewing. He is highly committed and well organised and was very keen to experiment and this has nudged his marathon PB forwards on 6 occasions in the last 5 years. His typical volume dropped by maybe 25% to 30% and the targeted sessions have continually evolved to seek marginal gains and all this as he aged past 40. So the culmination of 300 seconds of marathon improvement came in Valencia in December 2022,just after turning 41, when Paul got everything just so and further trimmed his PB to 2 

23.10, which ranked him 6th of all UK v40s for the year. 

 Chris, 26, London

To beat my former 17-year-old self. That was the target I had when first approaching Dave. It became clear that my ambitions would have to be bigger and within 6 weeks I’d revise that goal. Dave started coaching me in February 2018 towards the back end of the cross-country season and after implementing some fundamental changes to my training programme, positive results started to emerge. In early spring we managed to eclipse my 17-year-old self over the half marathon running 68:42, a personal best by over a minute.

Just over a month later I went on to PB over 10km, running 30:40. Within six months we had managed to rewrite my PBs over the 3,000m (8:25), 5,000m (14:29) and 10,000m (30:55). In the autumn 2018, after progressively increasing my training throughout the summer, I was in the shape to run a 2-minute PB for the half marathon running 66:29 for 21st place at the Cardiff Half Marathon incorporating the Commonwealth Championships. A year on, highlights from the 2018-2019 cross country season include a 4th placing at the Metropolitan XC League, 3rd at the Middlesex XC Champs, 8th in the Southern XC Champs, 31st at the English National XC Champs and 18th at the Inter County XC Champs (as part of the gold medal winning Middlesex team). My PB streak under Dave continues with a 66:10 clocking at the Reading Half Marathon in March 2019.

There are many things I value about Dave’s coaching, not least his endless knowledge and sincere passion for the sport. Most of all though, I value his honest approach, his challenging training ethos and the well-earned results it leads to.

My revised ambition… to beat my 26-year-old self.

Angela, 38, London

  Dave started coaching me when my marathon PB was 3.17,and introduced me to a structured training programme, based around my next ambition, a sub 3-hour marathon. The junk miles were dropped and a much more varied and satisfying way of training began. The rewards came with improved race times from 3k on the track to the marathon which has gradually improved to 2.49 and included wins in both the Edinburgh City and San Sebastian International Marathons.
Dave's strengths as a coach lie in his depth of knowledge and in his capacity to acquire new knowledge and stay abreast of current thinking. He is flexible with the training schedule whenever adaptations are required and he is open to feedback and responds to my opinions on what I feel works and what might need adjusting. Mostly, though, I trust what he tells me to do, because of the results I have seen. With the training being so varied, I stay motivated and Dave often comes along to races to give support, as well as offering advice on which races to enter. He gives generously of his time.
Angela again ran 2.49 on a hot day in the Flora London Marathon, placing 22nd in the Women's elite race. In 2008 she ran 2.50 in the London Marathon and early in 2009 ran 80.20 for a half marathon on Scotland. She moved back to Scotland in 2010.

Jake, 24, Oxford University, New Mexico, and London

I began training regularly at the local club as a fourteen-year-old in 2005 and progressed from 4.22 to 3.57 for 1500m in my teenage years with the help of several of the club coaches. In 2009, I felt that my progress was beginning to stall and that I would benefit from a more individualized training program, so I contacted Dave. Since beginning to work with Dave as my coach my times at all distances have improved dramatically and I have been more successful at avoiding and managing the injuries that I had previously been hampered by. I am now much more consistent in my training and racing and Dave has helped me to achieve the difficult transition from a promising junior athlete into a competitive senior athlete.

Dave has many strengths as a coach. His extensive and detailed knowledge of endurance training inspires great confidence, yet the rationale behind each training session is never overcomplicated. Dave is always happy to discuss why we are doing certain things in training and will go out of his way to learn new things if questioned on something that he is unsure about. He has some world-class contacts in all areas related to distance running, such as physiotherapists, podiatrists, strength & conditioning coaches, and other highly qualified coaches and athletes - all of which I have made good use of! He is very easy to contact and will always reply promptly , often to give common sense feedback on training that will appear obvious after Dave has pointed it out!

The amount of time and effort that Dave has put into coaching me is incredible , and shows the passion that he has for the sport. For me, the key thing that sets Dave apart from other coaches is his ability to really listen to what I am saying and to understand me as an individual athlete with unique training requirements.

Jake, whom I coached 2010 to 2016, is a highly talented runner, with PBs achieved in this period, of 3.43m for 1500; 7.59 for 3000m; and a big improvement to 13.46 for 5000m (12th ranked in UK at both 3k and 5k for 2015). He is also very knowledgeable and reflective about his running, so from a coaching point the challenge is to work with him on the 'one per centers' that will help him make further progress, for which he has considerable scope given his relatively low training mileage to date. He completed a coveted 2 year athletics scholarship at the University of New Mexico , aiming to make further inroads at his best distances. He debuted, very promisingly, at 10,000 metres on the track, acheiving 29.26 to place 12th on the UK Rankings for the year. He closed 2016 on the roads with a fine PB of 29.23.

Chris O 31, London “I started working with David in April 2017. After finishing the London Marathon in a big PB 2.33, I sought David’s advice to take the step up to reaching my next goal (sub 2.30). Within 12 months of working with David he has been fundamental in helping me reach my goal, achieving 2.29 in a very hot London Marathon in 2018. On the way to reaching my goal I have achieved substantially improved PB’s in 5k, 10k (31.28) & 13.1 miles (68.07), and this has largely been down to David’s training plans and regular advice. David has provided a clear training plan that works well around my very busy job as company director. This has allowed me to perform at work whilst also allowing me to perform in my running, something I have struggled to achieve in previous years.

David keeps things manageable, clear, simple but also focussed, and this has provided me the belief that the training plans will bring results, which they have done. Aside from training plans, David regularly keeps in contact, showing a real care for the individuals he coaches whilst always providing a great soundboard to discuss training. This was most recognisable after sustaining a stress fracture, in which period he was a fantastic positive energy throughout rehabilitation. Without doubt, I recommend David as a fantastic running coach but also a great guy, to anyone wishing to achieve their running goals. He makes dreams into reality. I look forward to continuing working with David, and seeing what else is achievable”

Chris had a good background of being well coached previously and was doing plenty of mileage so his improvements over one year – close to 2 minutes at 10k and 4 minutes at half marathon, at his high level, have been very pleasing and should still have plenty of upside. April 2019 and Chris had a great run in the London Marathon, 2.26.03, big PB and a coveted negative split to boot. This PB setting rolled on into summer, with 31.48 at the London Vitality 10k Road Champs and a 15.14 5000m at Wimbledon, followed a week later with a barrier-breaking 14.58 to place 3rd in the York 5k, and another Half Marathon PB in the classic Great North Run, 67.18.  After some ongoing niggles over 2020/21, not to mention the Covid period which ruled out racing, Chris returned really impressively in Autumn 2021 with a big PB of 2.22.40 at the Valencia Marathon. Four months later Chris returned to the Marathon fray in Manchester, almost matching his Valancia performance with 2.23.21. 

Martin, 45, North Wales

' I had been training consistently for 4 years and had brought down my marathon time gradually from 3.11 to a very pleasing 2.48, the latter based on a high mileage plan from the famous Pfitzinger schedules. I felt that to make further progress I needed a more individual and tailored approach as the mileage was pretty much at the maximum I could sustain. David has brought a  more detailed, varied and periodised approach to the training and this has been done without actually increasing the volume. Indeed, if anything it involves slightly lower but more specific mileage. With David's guidance I have done nine further marathons and set new PBs eight times [noone sets PBs in Snowdonia!]. '

Martin is a very sensible marathoner, and always balances ambition and reality in his goals and pacing, so that he has a great record of even splits in his marathons. He chooses his races smartly and each new marathon is tackled off a slightly higher 5k/10k platform. Martin took another major chunk off his PB, with 2.31.04 in the 2017 London Marathon, backed up with 2nd place in a very windy 2.34 at the prestigious Abingdon Marathon. Further, in 2018 he won the Trimpnell 20 in a PB, PBd´again in the Wrexham Half with 72.35, won the Wrexham Marathon in a 2.38 training effort and in a steamy London Marathon he bagged silver in the Welsh Senior Champs held within the race. Late Autumn brough Martin's self assessed 'best race ever' [revised in autumn 2020!] with second in the notorious Snowdonia Marathon and enough recovery to scoop a 10k PB of 33.03 in Telford, in his 45th year. London 2019 and the PB edged forward once more - 2.30.53. He is the 2nd fastest 45 year old Mr Green on this webpage. Another one to find new ommph as he hit 45, early 2020 saw Martin clock 32.32 at the Colwyn Bay, a new PB and again a very high UK ranking in the V45s, and a further very fine PB of 1.53.17 at the Wrexham 20 miles in March. The pandemic didn't affect Martin's comitment or fitness and so come October,and fresh from turning 46, in the Bedford Marathon he once again surpassed himself with a barrier breaking PB of 2.28.11, placing him 1st V45 in the UK rankings for 2020. Through 2021 further PBs at 5k and 10k and Half marathon came, all in the top handful of the UK 45+ age category, mixed in with two very fine and similar marathons at 2.30, at Cheshire in April and Manchester in October.

Mariah,31, London/Washington DC

I joined Serpentine in autumn 2008 and started working with David.  Through a series of conversations he helped me make some decisions about where I wanted my running to go and how best to get there. 

 David stressed the likelihood that my peak marathon times would be reached through strong racing ability in the shorter endurance distances.  In 2009 I ran a respectable half marathon in 1:22:10.  Since then I have now raced at a variety of distances with noticeable improvements, introduced non-running training such as strength and conditioning and pilates, and had a better cross country season with some satisfying results. She has set PBs of 10.07 at 3000 metres and 36.38 for 10k on the road.

Working with David has definitely been a really good experience.  He has a wide range of expertise and is able to suggest suitable races and training for my abilities and longer-term goals.  He is personable and easy to get in touch with, and his help with my training schedule is invaluable and takes so much pressure off.  Additionally he is flexible and understands that other things such as 'life' happen sometimes. 

Mariah has now moved back to Washington so we continue to plan the training by email. Fast forward to 2017 and now a fairly recent first-time mother Mariah has errrm popped out a 5 mile PB of 29.27 in the St Paddy's event in Washington state as part of the prep for a highly pleasing 2.51.04 PB in Berlin. Both her fastest marathon and her most well paced and managed on the day.

Martin, 35, London

I started running regularly in 2009. This involved running four times a week with the only really "structured" section consisting of running a few intervals around a square in London. After tackling my first marathon at Loch Ness in 2011, clocking 2.53, my supportive girlfriend fortunately put me in touch with Dave at the beginning of 2013, and I've been working with him since. 

 In that time my running has progressed markedly, and my enthusiasm for the sport has grown exponentially. Dave's input has been central to both. He has a truly thorough knowledge of the sport and thoughtfully puts this to use when devising highly individualised training advice, which from a personal perspective has greatly assisted me in becoming a better runner. He has also helped me set challenging, but realistic goals which have proved highly motivating (and satisfying when met). I would wholeheartedly recommend working with David for anyone who would like to progress in their running and realise the great enjoyment that comes from doing this.Over summer 2015 he focused on track, chopping his 5k time down to 15.45 and in March 2016 he ran 1.53.02 in the Finchley 20 miles, further progress  before pushing on to hit 2.30 in the London Marathon (where despite his PhD in Economics and repeated conversations on pacing with his PhD-less coach, he passed through half way in under 73 minutes and so had to compromise in the final miles to keep on track).  Big breakthrough in Berlin 2017 with 2.27.15 - which as he reckoned he could run 3.29 per km if all went just so was very well handled - at 3.29/km. 2019 brought some further PBs, most notably 69.03 at the Cardiff Half Marathon and 30.51 at the Leeds Abbey Dash 10 (23 metres short!).  And in autumn 2021, nor relocated as an Assistant Professor at the University of Wisconsin, Martin achieved his best ever raceing performance, a very strong 51.18 in the Philadelphia 10 Miles.His training volume is somewhat higher than when he ran 2.53 of course, but he has a balanced life and a demanding career to fit around the running.  Martin ran the race of his life so far in the brutally windy Indianapolis Marathon in November 2022, with a PB of 2.25.57 that would have been a chunk quicker in more normal conditions. Fast forward to January 2024 and a big further advance was chalked up in the Houston Marathon, with 2.22.29 which placed Martin at the head of the UK Marathon Rankings for a month!

The coach

David Chalfen

David is a runner and coach with over 40 years experience, and 18 years in coaching with a focus on longer distances, up to the marathon.  Qualified at Level 4 (Performance - 10k to Marathon) within UK Athletics coaching system, and at Level 3 in Strength and Conditioning, he has extensive and diverse practical experience to support the formal qualifications.  From 2009-14 he was one of England Athletics Area Coach Mentors in Endurance. He has managed numerous elite runners, both African professionals and GB internationals, at big city marathons such as Berlin, Istanbul, Seville, and Lahore . He once hosted former World Marathon Record Holder, Patrick Macau (2.03.37!) at his house though claims no direct influence on this athlete beyond giving him two chilled lagers and a chauffeur service to Finsbury Park station. He has also acted as England Marathon National Team Manager.

His book 'Improve Your Marathon and Half Marathon Running' was published by Crowood in September 2012 and is on England Athletics' recommended reading list for endurance coaches and runners.  Four times Olympic and World Championships marathoner Dan Robinson said of the work 'His dynamism and expertise come across brilliantly in this extremely well written, useful and entertaining book'. The world renowned 'bible' of athletics, Athletics Weekly, reviewed the book with ‘Its pages cover everything you need to know in your quest for that perfect half or full marathon. ’ 

 He is now a member of Highgate Harriers and was previously atSerpentine Running Club and coach to many of that club's runners who formed the country's leading men's marathon squad. As a runner he achieved a 2.32 marathon and 10 sub-2.35s. He doesn't use any social media for the same reason that he doesn't have his teeth pulled out without anaesthetic - it would just make him uncomfortable.

In a professional capacity, he has picked up much best practice from working for several years on Sport England’s and UK Sports World Class Programmes that support elite British sport.
He says:-

By a mixture of luck and design my early running, from age 14 was with the mighty Shaftesbury Harriers and then 3 years at Oxford University Cross Country Club where my 'achievements' included being not good enough to reach Blues level and struggling with TS Eliot. But I had the running bug far more embedded than any actual athletic ability, and I stuck to the task and was pleased to earn some Middlesex vests in my late 20s. 

I started coaching 20 years ago after over twenty years of training and racing through the age groups. As a self-coached runner I was always very keen to put in plenty of miles but underachieved through not training smartly enough and not having an objective external guide to shape the training and recovery as sensibly as it could have been. 

The progress made by the numerous runners I continue to coach as a volunteer in the traditional club environment led me to extend the coaching commitments via this website. The technical knowledge and experience I have developed with many quicker runners is applied individually to runners at various levels.  

I stress variety and progression across all programmes so that, whilst one can never avoid doing the underpinning volume and regularity to make progress, there are an infinite range of different ways of structuring the training sessions to achieve the required physical challenge. Or to quote the coach of the 2016 GB Olympic Champions Hockey squad "If variety is the spice of life then repetition is the porridge".

Photo -  Maren Urner

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