How fast should a long run be?

In March 2009, when I was weighing up the possible plans for summer training in preparation for a half-marathon in September of that year, I had explored the Furman program [1].  It is an attractive program for a runner with limited time available for training because it comprises three running sessions per week: an interval session, a tempo run and a long run, together with a flexible amount of cross-training.  At that time I wrote: ‘The thought of a weekly interval session and a weekly tempo session is not too worrying.  Two such sessions are typical of many moderate or high intensity programs.  However, the Furman session that most concerns me is the long run.  The Furman program emphasizes the importance of achieving the designed paces for all sessions.  In the 18 week half marathon program, the pace for the majority of the long runs is Half Marathon Pace + 12 seconds per Km or faster.’   

At that time, I decided on a program that was more closely related to a Lydiard approach consisting of a mixture of low, mid and upper aerobic runs, though far less in total volume than the 100 miles per week that is widely regarded as the defining feature of Lydiard’s approach to base building.   As things turned out, my training was seriously disrupted by a prolonged and debilitating illness in mid-summer and I ran the half marathon in September one the basis of very limited preparation.  This year, a half marathon in September will be my main target race, and I am again faced with planning the details of my program.

Unfortunately I have already had some health problems this year, and am struggling to recover the level of fitness I had achieved in January.  Nonetheless, I still have about 16 weeks to prepare for a race in September. My primary goal is to build up my aerobic capacity, though I will also continue to work on rebuilding some of the leg strength that I have lost in the past decade.   For achieving aerobic fitness with a limited time budget, tempo runs are probably the most efficient type of session, but to minimize the risk of recurrence of the illness that has hampered me, I can only afford to indulge in tempo runs sparingly.  So the weekly long run will be a crucial part of the program.  But this brings me back to the question that I faced when had looked at the Furman program last year: how fast should the long runs be?

The answer depends at least partly on what other training one is doing, and on one’s specific goals.  In preparing for a half marathon the crucial thing is establishing the ability to sustain a pace near the upper end of the aerobic zone for 21 Km.  At first sight, the Furman long run at HMP + 12 seconds or faster seems the obvious answer.  Observing the progress of various runners who have recorded their experiences with Furman on their blogs has confirmed the evidence from scientific studies indicating that the program works – a runner who copes with the program has a good chance of achieving the target race time. However, most runners report that it is tough.  Despite the fact that there are only three specified runs per week, I suspect that in many instances, the runner is on the dangerous far-side of the sweet spot – and verging towards the territory where the risks of injury and ill health rise disproportionately.

 Looking towards Africa

In an era when Africans hold virtually every world record for distances ranging from 1500m to the marathon, the most obvious starting point in addressing the question: ‘how fast should a long run be?’ is to examine the training patterns of Africans.  In fact there is no single African training pattern, and in any case several factors other than current training are likely to contribute to the prodigious success of African distance runners.   However, whatever the contributions of geography, culture or genes, training almost certainly plays a substantial role, and it is perhaps the one feature that might be adapted by any runner.  So it is worthwhile examining the approaches to the long run adopted by contemporary Africans to see if there are any essential features can be identified.  

I have chosen fours runners: two youngsters from Kenya who have made spectacular debuts in international marathons within the past few years, but who have quite different approaches to training, and two ‘veterans’ who dominated international 5000m and 10000m  track events at the end the final decade of the last century, and have between them, held the world marathon record for much of the first decade of this century. 

The two youngsters are Samuel Wanjiru, who won the gold medal in Beijing in 2008 shortly before his 22^nd  birthday setting a new Olympic record of 2:06:32; and Robert Kiprono Cheruiyot, 21 year-old winner of the tough Boston marathon in a record time of 2:05:52 in 2010.  The two ‘veterans’ are Paul Tergat from Kenya and Haile Gebrselassie from Ethiopia, who both reached their peak on the track around the turn of the century, before moving to the marathon.   One of the highlights of the Sydney Olympics in 2000 was the titanic battle in the 10,000m in which Gebrselassie narrowly defeated Tergat.  Tergat ran his debut marathon in London in 2001 and in 2003 became the first person to run a marathon in under 2:05 when he established a world record of 2:04:55 in Berlin.  Gebrselassie made his marathon debut in London in 2002, and in 2007 in Berlin took 29 seconds off Tergat’s world record, before going on to become the first person to break 2:04 with a time of 2:03:59, a year later, again in Berlin   

Samuel Wajiru

Japanese journalist, Akio Harada of the Asahi Newspaper, obtained a fascinating insight into the training of Samuel Wanjiru during an interview before the Fukuoka marathon in 2008 [2].  Wanjiru had established a new course record of 2:06:39 in his international marathon debut in Fukuoka the year before.  Harada’s question to Wanjiru about Catherine Ndereba failing to win gold in Beijing because she had not realized until too late that Constantina Tomescu was ahead of her provided an interesting insight into Wanjiru’s mental approach to racing.  Wanjiru had not seen the women’s race but his comment was ‘but I’m not the type of guy who runs behind someone else.’   In contrast, his approach to training was perhaps best encapsulated in the remark; ‘Sundays are off, and if it rains I also take the day off from training. If you train too hard in the summer it’s bad for your body.’

He described his training in the months leading up to the Beijing Olympics in August 2008.  He did long cross-country runs of 38 Km; somewhat faster runs of 30Km on flat ground; and speed work, such as 10x400m or 3x3000m.  In addition, about half of his training days were described as easy days.  The 38Km long runs were at a pace of 4:30 per Km (7:12 per mile).  This pace is 50% slower than his marathon pace.  For a 3 hour marathon runner, the equivalent pace would be 10:17 per mile.  It should be noted that these runs were at altitude and also cross-country.  As an aside, I was interested in his comment:  ‘I never do any strength training. You can get enough strength from running on cross-country-type courses.’   Nonetheless, his long run pace suggests that many of the benefits of the long run can be obtained by running at a very gentle pace; a pace that is ‘not bad for your body’.    His 30Km ‘pace runs’ were run at a pace only 5% slower than his marathon pace, and hence might be regarded as tempo runs.  

Thus, as in the Furman program, Wanjiru’s training included speed sessions, tempo and long runs, but the really striking differences are that his long runs were much slower than the Furman marathon program would recommend, and his total volume was higher.  In particular he added substantial volume on his easy days, some of it apparently in the form of progressive runs. He told Harada:  ‘Other than that, I run about 15 km at 7:00 or 8:00 in the morning before I have breakfast. I’d say it’s like jogging, or a buildup to something like a pace run. I start around 4 minutes per km, drop it down to 3:30 in the middle, then end up down at about 3 minutes 5 seconds. I always want to finish thinking, “Aaaaah, that felt great. I had a good run.”’

Robert Kiprono Cheruiyot

Robert Kiprono Cheruiyot made his international debut at the Commerzbank Marathon in Frankfurt in 2008, winning in the new course record time of 2:07:21.  A year later, Larry Eder published details Cheruiyot’s training leading up to the 2009 Frankfurt marathon on RunBlog [3].  At that time, Cheruiyot was running around 280 Km per week in training, in contrast to Wanjiru’s total volume of around 140 Km per week.  Cheruiyot also included a mix of long runs (typically 40Km, midweek); a somewhat faster paced 30Km on the weekend; and a weekly ‘speed’ session.  However his typical speed session was 12x1000m at 3:00 min/Km, which is slightly slower than his marathon pace and hence is likely to be comfortably below the anaerobic zone.  Eder did not report the pace of the 40Km long runs, but the schedule makes it clear that the majority of Cheriuioyt’s training volume was provided by 15-16Km runs at a pace about 1 ½ minutes per mile slower than his marathon pace.  Thus the overall picture is of a program with very high volume but only moderate intensity.   

Paul Tergat

However not all of the Kenyans place quite so much emphasis on avoidance of excessive stress.  Among those with a legendary ability to tolerate hard training is Paul Tergat.  The biography ‘Paul Tergat: Running to the Limit’ by Jurg Wirz [4], emphasizes Tergat’s commitment to developing mental toughness.  The training programs described in the book appear relentless in their demands.  For example during his preparation for the 2002 London marathon, the  total volume weekly volume was  well over 200Km per week including 7 quite demanding morning sessions and 6 easier afternoon sessions.  The 7 morning sessions typically included one or two sessions of speed work, a long run and three or four sessions of 70- 75 min which are described as ‘always medium to fast’.  The long run is described as ‘not slow at all’.  The easy afternoon sessions were typically 1 hour at a slow to medium pace.     

Nonetheless it is noteworthy that unlike many other Kenyan distance runners, Tergat did most of his training at a relatively low altitude of around 1700-1800m, near his home in Ngong on the outskirts of Nairobi.  In 2001 he had trained for about two months at an altitude of 2300m in the Kaptagat Forest at Eldoret, but he found this very exhausting.  He reports that ‘by evening I was very, very tired’.  Thus, despite the apparent Herculean character of his training schedules, even Tergat was aware of the need to avoid getting too tired.

It is also noteworthy that following the exhausting high altitude training in 2001, he was second in the London marathon in a time of 2:08.  While this is a very creditable debut marathon, when the Morrocan Abdelkader El Mouaziz  had applied the pressure at 35 Km, Tergat could not stay with him.  In 2002, Tergat was again second, ten seconds behind Khalid Kannouchi’s new world record time of 2:05:38.  In 2003, Tergat reached the high point in his marathon career with his world record of 2:04:55 set in Berlin. Had he perhaps trained just a little too hard in 2001?  And, since 2003, he has not achieved the same heights again.  His most recent, and perhaps final, marathon victory was in the 2009 Lake  Biwa Marathon in Japan, which he won in 2:10:22.  It would be churlish to criticize the achievements of Tergat’s remarkable running career, a career than has earned him  a place in the Pantheon of running greats, but I can’t help wondering whether or not he might have sustained his marathon performance at the very top level  for a few years longer if he had adopted a slightly more relaxed attitude to training. 

Haile Gebrselassie

While Tergat has earned a place in the Pantheon, in my opinion the man who is entitled to be described as the greatest distance runner of all time is Tergat’s friend and rival, Haile Gebrselassie.  Not only is he the current world marathon record holder, he has established a total of 27 world records over distances from 2000m to the marathon during his career, and in addition, has run some superb competitive races, of which the 10,000m final in Sydney stands out.  However, as an old timer hanging onto a shred of nostalgia for the days of amateurism, it is with wry amusement that I am forced to go to the website of one of Gebrselassie’s commercial sponsors, Powerbar, for details of his training. 

The example of Gebrselassie’s training provided on the Powerbar website [5]  demonstrates that his a weekly program includes speed work, a tempo run and a longish run together with a fartlek session and easy runs giving a total weekly training volume of 190 Km (120 miles) .  His speed work consist of 6x2km @ 2:50 /Km which is slower than his best 10Km pace, with 3 min recovery; and also 10x100m sprints within two of his easy sessions.   In his tempo session he covers 15Km in 48 min.  (i.e. 3:12 /Km) which is about 7% slower than his marathon pace.  His longish run is 25Km in 90 minutes  (i.e.  3:36 /Km or 5:45 /mile; for a three hour marathon runner that would correspond to 5:14 /Km or 8:22 per mile).

The easy sessions include a 20 Km run at 4 min per Km and two 18Km runs at a similar speed, in addition to five easier runs, such as 10Km in 43 minutes (4:18 per Km, which is 46% slower than his marathon pace; for a three hour marathon runner, that would correspond to around 6:15 per Km or 10 min/mile). 

In summary, Gebrselassie’s program is fairly high in both volume and intensity, but even the higher intensity runs are not very intense.   His 25 Km long runs are shorter than the corresponding 38 Km runs of Samuel Wanjiru but somewhat faster.  The pace of Gebrselassie’s 25km runs is about a minute per mile slower than his marathon pace.  Some of his easy runs appear very easy – such as 10Km in 43 minutes which is a pace equivalent to 10 min/mile for a 3 hour marathon runner.  It should however be noted that much of his training is done at an altitude of around 2700m. 

In an article about her experiences arising from Gebrselassie’s invitation to her to visit Ethiopia, Canadian 1500m runner Hilary Stellingwerff reports that Gebrselassie placed great emphasis on mental preparation; on the need to deal first with one’s inner demons.   “First you must win yourself. Of course you must train hard, but after that, everything is easy.’ [6]  She describes her humbling experiences as she joined in with the local athletes running a 16Km loop in the mountains not far from Addis Ababa and concludes “Athletics comes number one for African athletes; there is nothing else. They train very hard and sleep the rest of the day to recover.’  However she also points out that they respect the body.    She writes; ‘Finally, on all my recovery runs, the Ethiopian athletes stressed the importance of running on soft ground in the forest to make sure you go slow enough to really recover. They don’t worry too much about their pace, but instead about “getting good oxygen” from the trees and “soft ground” for the body.’

Synthesis

As might be expected, there is no single answer to the question of how Africans train, but several clear themes emerge.  Elite Kenyan and Ethiopian distance runners adopt a program comprising speed work, ‘pace’ or tempo sessions, long runs and easy runs.  The speed of the long runs is at least 1 min per mile slower than marathon pace and often slower.   The easy runs appear very easy by European standards.  Strong determination is balanced by an over-arching spirit of respect for the body.

Overall, the spirit that can be distilled from these accounts of the training of elite Kenyan and Ethiopian distance runners is perhaps a little nearer to the spirit of Ed Whitlock (discussed in my post on 22 April) who trains 3 hours per day, mostly at very low intensity, than it is to the remorseless pressure of the high intensity Furman program, despite its low volume.   I still consider the Furman program has much to recommend it, but I am even more certain that my initial concern, expressed last March, that Furman long run paces are too demanding, was well founded.   In the months ahead, I will aim for long run paces that are at least a minute per mile slower than a speculative estimate of my marathon pace.

London Marathon 2010

As a footnote to my posting on the Sweet Spot on 22 April, Marie and her husband did cross the line together on Sunday in the 2010 London marathon.  The truly inspiring achievement was Marie’s determination to celebrate the experience and to get her medal. 

Another inspiring achievement was the 2:47:34 recorded by Rick Bowker, the ‘No limits desperado’ of Rick’s Running.  He had prepared tenaciously following Marius Bakken’s 100 day program.  Finishing in 376^th place overall (and 30^th  in the 45-49 category) while taking around 4 minutes off his PB was a great achievement.   Well done, Rick, and thanks for all your comments on this site over the past year.

References

[1] Bill Pierce, Scott Murr and Ray Moss (2007) ‘Runner’s World Run Less, Run Faster: Become a Faster, Stronger Runner with the Revolutionary First Training Program’

[2] Akio Harada (2008)  ‘Samuel Wanjiru shares the secret of training to win.’, published in the program for the 2008 Fukuoka marathon; translated from Japanese by Brett Larner with editorial assistance from Mika Tokairin, and posted on http://japanrunningnews.blogspot.com/2008/12/samuel-wanjiru-shares-secret-of.html

[3] Larry Eder (2009)  ‘Robert Kiprono Cheruiyot: training log, from Victah Sailer, Notes by Larry Eder’.  Posted  23 Oct 2009 at http://www.runblogrun.com/2009/10/robert-kiprono-cheruiyot-training-log-from-victah-sailer-notes-by-larry-eder.html

[4] Jurg Wirz (2005) ‘Paul Tergat: Running to the Limit’

[5] http://www.powerbar-europe.net/913/2395/uk/athletes/powerbar-athletes/haile-gebrselassie-runner.powerbar

[6] Hilary Stellingwerff (2009)  ‘Living the High Life.’  Canadian Runner, Issue 2.4

The sweet spot

In a comment on my blog in October 2009, Ewen pointed out the contrast between the training of two Kenyans marathoners, Robert Cheruiyot and Sam Wanjiru.  Cheruiyot runs 280Km per week, mostly in 15Km runs at a pace about 1 ½  min per mile slower than his marathon pace, while Sam Wanjiru runs 140 km per week with a much larger proportion of high intensity sessions.  Both have run marathons in around 2:06. The re-assuring conclusion is that both low intensity, high volume programs and high intensity low volume programs can work.  Does it matter which type of program an individual adopts? 

There are clearly pragmatic factors, such as the time a runner has for training each week   For the time being, I can afford to spend  4-5 hours per week training and that rules out a high volume program.  It is probable that physiological factors, especially the proportion of slow twitch (type 1) fibres  in your leg muscles, also affects which option that will work best for you.  In my case, I am fairly sure I have a preponderance of slow twitch fibres, which might indicate that a low intensity, high volume program would play to my strengths.  On the other hand, it might also be argued that as my fast twitch fibres deteriorate with age, I would be ill-advised to ignore them.  

However, I suspect that the most important determinant of success in a training program is adjusting load and intensity to hit the sweet spot, where the amount of stress on the body is sufficient to promote fitness, but a little short of the level that leads to over-training, injury and eventually to ill-health.   

Two recent happening have focused my attention again on the sweet spot.  First, was another comment from Ewen: a reminder of the spectacular achievements of Ed Whitlock, who has assembled an incredible collection of world records during his seventies, based largely on running fairly slowly for three hours per day.   Typically he covers around 200 Km per week mostly running at a pace1-2 minutes per mile slower than his marathon pace, on a 1/3 mile loop in a cemetery near his house on the outskirts of Toronto.  The other was an event in the life of a young woman, whom for present purposes I will refer to as Marie [1], who had contacted me a little over a year ago in response to one of my postings regarding training on the elliptical cross-trainer.  It transpired that Marie and I shared an approach to running that included a delight in running through bluebell woods as much as setting race goals.  Over the past year we have discussed running and training fairly regularly via email though we have never actually met.  I will return to Marie’s story shortly, but first, let us look at some of the features of Ed Whitlock’s training.

Ed Whitlock

Ed Whitlock holds 13 age-group world records for distances ranging from 1 mile to the marathon.   His records include the phenomenal marathon record of 2:54:48 for the 70-74 age-group; and the record of 3:04:58 for the 75-79 age-group.  On the LetsRun forum in April 2009  he confirmed that when he established the 70-74 world record in 2003 that the major component of his training was daily three hour runs at a low intensity.  He wrote:

‘I ran my “2:54″ at age 73 in 2004 off an extended base of daily 3 hour slow runs. ……I started extending the duration of my daily runs in my mid 60′s gradually increasing to the occasional 3 hour run by the time I was 70. I always try to increase “mileage” slowly and not make sudden leaps.’  [2]

Further details of his program and some interesting insights into his approach to training are provided in two very interesting interviews: one by  Pete McGill in March 2008 for the Younger Legs for Older Runners website [3], and the other by Scott Douglas, in March 2010 for Running Times [4]

He comes across as a man with an ironic sense of humor who takes impish delight in portraying himself in a curmudgeonly manner.  He emphasizes that he does not run for pleasure, but simply because he wants to break records.  He has no interest in running on woodland trails or pleasant countryside.  He chooses to train in a cemetery for purely pragmatic reasons: it is near to home, free of traffic and during a 1/3 mile loop he does not face long periods battling a head wind.  In fact it appears that he carefully avoids anything that might be acutely stressful. He avoids the one stretch of the path where there an appreciable hill. 

What is the key to his success?

It is clear that Ed Whitlock is naturally gifted.  As a school boy, he beat Gordon Pirie in a cross-country race, but in subsequent years, Pirie’s massive training volume propelled him to a series of dramatic 5000m and 10,000m duels with Vladimir Kuts in 1956, and to a world record in the 3,000m.  Meanwhile Whitlock stopped running for a period of over  15 years before resuming training again in his forties.   In his late forties he achieved his marathon personal best of 2:31:23  Thus he was endowed with a moderate natural talent for running, but it appears to be the high volume, low intensity training that transformed him into one of the most phenomenal veteran distance runners ever.

It is not clear to me what are the most important physiological changes produced by long slow runs.  Dudley’s studies of rats suggest there is little further increase in oxidative capacity of type 1 fibres (assessed by measuring cytochrome oxidase ) after  30-40 minutes of low intensity running [4].  Very long runs might be expected to increase in capacity to store glycogen and also to metabolise fats – but that doesn’t account for Whitlock’s achievement over shorter distances.   It would seem logical to assume that once the type 1 fibres are exhausted, the type 2A fibres are recruited, but Dudley’s data do not provide much evidence for that.  Maybe Dudley did not keep his rats running for long enough at low intensities to fully exhaust the type 1 fibres – or maybe humans are different from rats.

But I suspect the key to understanding Whitlock’s success is the steady build up over many years while subjecting himself to minimal acute stress.  His avoidance of hills and troublesome head winds suggests that he was not driven by any sense of necessity to subject his body to harsh discipline, but rather he worked in harmony with his body, gradually increasing the daily distance as he felt able to cope with it.  In other words, I suspect that he continually made gradual adjustments to his training to keep himself near at the ‘sweet spot.’ – the level of training load adequate to provide continual stimulus to improve while avoiding overtraining and risk of injury.  Though it should also be noted that in the midst of his low intensity training he did race fairly frequently.    

There were probably times when Whitlock did pass beyond the sweet spot.  When he ran the Columbus marathon in 2:52:47 in 2000, only months before his 70^th birthday, it seemed that the target of setting a 70-74 age group record under 3 hours was easily within reach, but problems with arthritis in his knee, perhaps only partially related to his running, stopped him achieving that target for over two years.  Nonetheless, the striking characteristic of his attitude towards training over the years has been a sense of harmony with his body rather than subjugation, despite the fact that his primary motivation has been the pursuit of records. 

 

Marie

Marie is also a dedicated runner and is undoubtedly in the elite class when it comes to enjoyment of running, but her goals are somewhat different from those of Ed Whitlock.  When she first contacted me to ask about elliptical cross training, she was recovering from an injury to the peroneus longus tendon, and she stated that her primary goal for 2009 was to enjoy running in the English countryside.  We shared anecdotes about the wildflowers, birds and other wildlife that we each encountered during our running, but from the seriousness of her approach to the issue of elliptical cross training, it was fairly clear that she also had her eyes on an additional goal for 2010.  I was not completely surprised when some months later she announced that she and her husband had been successful in the lottery for places in the London marathon in April 2010.  We discussed, via email, her proposed marathon training plan in which the key feature was a series of races of increasing distance.  It seemed to me a sensible plan, though she had included what appeared to be just one too many demanding races in the schedule for February. 

Although I have described her as young woman on account of the freshness of her spirit, she is in fact of an age where natural anabolic processes start to slow down, and recovering fitness after injury tends to be a slow process.    So I was not that surprised that she found increasing the distance of her long runs according to plan to be quite demanding.  Nonetheless, she managed the program almost perfectly.  Most of her runs were at a pace more than a minute per mile slower than I considered she would be capable of in the marathon.  She dropped the excessive race from the schedule for February, but otherwise she stuck to the plan almost exactly.   It seemed to me she was keeping her training load right at the sweet spot.  For a brief period in early March she became a little worried that she was not going to get the planned 20 mile runs done in time, and for a couple of weeks she was inclined to push herself a little too hard, but after a review of the situation, she got back in a good rhythm.  She completed the 20 milers according to plan, and was by this stage finding it easy to maintain a pace faster than planned marathon pace in her shorter runs, despite the fact that most of her earlier training at been a much slower pace.

Two weeks ago, she mentioned that she had been a little distracted that week because she had discovered a suspicious lump and had had a biopsy.  Nonetheless, her training log for the following few days showed that she was feeling exhilarated running at marathon pace over fairly short distances, as she began the taper.  I was reassured, but nonetheless woke up in the night worrying about her several times during that week, and had to remind myself that there wasn’t really much reason to worry.  Then a week ago she sent an email saying that the biopsy had proven positive.  She has cancer and is scheduled for surgery at the beginning of May.   

While I was fairly confident that Marie would develop a strategy for maintaining her equilibrium during the uncertain times ahead, I thought it unlikely that the marathon would be high on her list of priorities.  However I had under estimated her spirit.  Despite the myriad questions regarding the tumour and the operation that must have crowded into her mind during the meeting with her surgeon, she asked whether or not it would still be OK to run the marathon about two weeks before surgery.  The surgeon’s answer was yes. 

She sent me another email telling me of her plan.  She would take part in a five mile fun-run in Oxford the week before the London marathon. After that, she would do one or two more short runs and then the only really important remaining part of the marathon preparation would be getting her hair done the morning before the race.  

I am recounting her story here largely because her spirit is inspiring.  However, it has also brought into sharp focus the question of defining the sweet spot.  As described above, it is the place where the training load provides enough stress on the body to promote fitness, but is a little short of the level that leads to over-training, injury and eventually to ill-health. 

A substantial body of evidence indicates that exercise reduces the risk of onset of cancer and also that continuation of exercise following diagnosis of cancer increases survival rates. For example in early-stage breast or colon cancer, exercise can increase survival rate by 30-50%  [5]  This is not surprising because it is well established that moderate exercise increases immune responses and other potentially beneficial responses to inflammation.   However, excessive exercise can suppress immune responses, so one would expect that beyond a certain sweet spot, the benefits of exercise might be lost.  There is little clear evidence to indicate where this sweet spot might lie, though the available evidence suggests that that it might lie well into the range of quite strenuous exercise.

This question was addressed in a study of the rate of growth of lymphoid tumours in mice by Zielinski and colleagues [6].  The investigators set out to test the hypothesis that strenuous exercise in the form of running on a treadmill for three hours daily, or until exhaustion, might actually accelerate the rate of tumour growth.  However, in contrast to the investigators prediction, even this strenuous level of exercise delayed the growth and resulted to a more rapid regression of the tumours, in comparison with tumours in mice who led a sedentary lifestyle.  While this observation is encouraging, one must be cautious in applying lessons learned in mice to humans.  So I am inclined to think that running oneself to a state of utter exhaustion unlikely to be sensible, but provided one stops well short of utter exhaustion, the evidence indicates that running might inhibit tumour growth.

 Marie, if you read this, it is clearly important to be guided by what your surgeon recommends.  I am certainly not an expert, but I was delighted to hear the surgeon’s advice that running the marathon would be OK.  It fits with the evidence from the study by Zielinski.  Nonetheless, I think you are being very wise to be treating VLM 2010 as a race to enjoy – not a test of endurance.   If you and your husband run together down the Mall at the end of 26.2 miles that will be wonderful, but above all, look after yourself on Sunday.  It is the fact that you are going to be on the starting line together that is the real tribute to your spirit.  Nonetheless in the months ahead, continuing to run – or if needs be, combining walking and running – is likely to be the path to the sweet spot.

[1] Marie is a pseudonym

[2] http://www.letsrun.com/forum/flat_read.php?thread=3200366

[3] http://petemagill.blogspot.com/2009/03/ed-whitlock-profile.html

[4] http://runningtimes.com/Article.aspx?ArticleID=18810

[5] Dudley et al (1982) ‘Influence of Exercise Intensity and Duration on Biochemical Adaptations in Skeletal Muscle,’ Journal of Applied Physiology, vol. 53, pp. 844-850.

[6] Jones et al (2010) Effect of aerobic exercise on tumor physiology in an animal model of human breast cancer J Appl Physiol 108:343-348,

[7] Zielinski et al (2004) Exercise delays allogeneic tumor growth and reduces intratumoral inflammation and vascularisation J Appl Physiol 96:2249-2256.

A review of progress

My plan to prepare to run a marathon in 2012 got off to a promising start, but in the past few months I have struggled with ill-health, and it is time for a review.   I had taken up running again in middle age, with the principle goal of getting fit.  But lurking in one of the shallow recesses in my mind was the dream that after I retire from work in 2011, I might train for a marathon.   After three years of fairly regular but mainly low intensity running, I have developed a moderate level of fitness, but I have been a little disconcerted to realize just how difficult it will be to recover even a pale shadow of the fitness of my younger days. By the end of last year, I had run 3 half-marathons, with times ranging from 101 to 103 minutes, and I had enjoyed a few minor triumphs in shorter races, but it is clear that if I am to make any progress against the tide of age-related degeneration, I need to have a systematic plan to deal with some of my weaknesses.

The first issue is that despite running fairly regularly since my early sixties I have been losing muscle strength steadily, and my stride length has shrunken.  In an attempt to deal with this, in the three months from November 2009 to January 2010 I had done a moderate amount of body-weight resistance work.  I achieved a modest improvement in strength. I had increased the distance that I could cover in 5 consecutive hops for 9.01metres to 9.71m in the left and 8.56 m to 9.30 m on the right.  My right leg has been weaker for many years as a result on intermittent attacks of arthritis.  Unfortunately, in January I suffered yet another episode of arthritis.  It started in my neck but eventually spread to my knees though this time it has mainly been the left knee that has been affected.  Although the pain resolved within a few weeks, I have had various other complications that have limited my ability to resume systematic training.

I am still wary of putting too much load on my knees so I will proceed cautiously with leg strengthening for a little while longer.  Meanwhile, my medium term goal is a half marathon in September, aiming for a time under 100 minutes.

Developing aerobic capacity

The paramount requisite for the half marathon is aerobic capacity.   To run a good half marathon, it is necessary to be able to sustain a pace near to the anaerobic threshold with only slight accumulation of lactate for 13.1 miles.   Since the anaerobic threshold is the point at which lactate production increases markedly, production is relatively low below this threshold, but is nonetheless appreciable.  It is essential to develop a good capacity to metabolize lactate.

There is a bewildering array of claims about the best training program for increasing aerobic capacity.  In fact, there is good evidence that quite different types of programs ranging from high volume approaches advocated by Arthur Lydiard or high intensity programs, such as that developed by the Furman Institute can be successful.   While it is encouraging to know that there are several of ways to achieve the goal, the challenge is finding the style of training and amount of training that produces the best result for each individual.  How can we find the sweet spot where training is maximally constructive without becoming destructive?

Looking back

The starting point is examining one’s own history of response to training.  In the days when I ran competitively, I was actually more enthusiastic about mountaineering than running, and it is difficult to disentangle the effects of mountaineering from the effects of my running training.  In those pre-internet days, knowledge about training methods was largely spread by word of mouth.  The local gossip included accounts of Percy Cerutty’s advocacy of running up sandhills, and Lydiard’s advocacy of running 100 miles per week.  I rarely ran up sandhills, but there were a few brief periods when I ran 100 miles a week.  However mostly, rather than waste time on long easy-paced runs, I preferred to spend long days carrying a heavy pack in the mountains.  Most of my running training consisted of runs of 5-10 miles at ‘a good aerobic pace’.

Measuring heart rate while running was not practical for the amateur athlete forty years ago, but I did use my breathing as a guide.  I usually trained somewhere between the point where my breathing became quite noticeable (at a rate around 45 breaths per minutes) and the point at which it became labored and increased to about 90 breaths per minute.   Although terms such as lactate threshold, aerobic threshold and anaerobic threshold were not commonly used in those days, in retrospect I suspect that onset of noticeable breathing at 45 /min probably corresponded approximately to aerobic threshold while laboured breathing at 90 / min was probably a little above anaerobic threshold.  I rarely ran any slower than 6 minute miles in training.  I suspect that in today’s terminology, most of my runs would have been described as tempo runs, though they were rarely demanding.  So in summary, mountaineering provided my base fitness and ‘good aerobic’ tempo runs provided ‘race fitness’.

Because I was not really serious about running, I have not kept any records of my race times. I had a few memorable moments on the track, but I ran track races mainly to earn points for my club in the interclub competition.  I had a slightly more notable career as a marathon runner   I raced four marathons.  I won the South Australian State championships in the late 1960’s; I subsequently represented South Australia in a reasonably creditable manner at the Australian national championships; I didn’t finish on another occasion due to an asthma attack precipitated by a chest infection; and I contributed to my college team’s third place in the PolyTechnic Harriers marathon in London in the early 70’s.   My fastest time was around 2:25, in the Poly.

I will never know whether or not I might have done better if I had devoted myself more single-mindedly to running, but I suspect that my training suited my natural physiology quite well.   Perhaps due to genes, or to running to and from school as a youngster, or a combination of both, I am fairly certain that I have a predominance of slow twitch fibres.    According to Dudleys famous studies of rats running on a treadmill (Journal of Applied Physiology, 53; 844-850; 1982)  the most effective way to improve the aerobic capacity of slow twitch fibres is  to run in the upper aerobic zone for about 60 minutes per day, 5 days per week.  I suspect my frequent 5-10 mile ‘good aerobic’ tempo runs were not far short of perfect for maximizing my aerobic capacity, and my treks in the mountains  provided the necessary base fitness.  I am also intrigued to note that Marius Bakken reports that his observations during his time in Kenya indicated that Kenyans do a lot of their training just below the lactate threshold. http://www.mariusbakken.com

The current situation

Unfortunately, now I am in my mid-sixties I do not recover quickly enough to do frequent ‘good aerobic’ tempo runs.  Even more unfortunately, I now rarely have the time to spend long days in the mountains.    Nonetheless, without specifically planning it, my recent training has followed a pattern that bears some resemblance to the training of my younger days, though greatly reduced in both volume and speed.  The long days in the mountains have been replaced by fairly regular longish (15-20KM) easy paced runs.  The majority of my ‘faster’ runs are 8-10Km ‘good aerobic’ tempo runs or progressive runs in which I start slowly and work up to a good aerobic pace for the final few Km.  I also do some tempo style sessions on the elliptical cross-trainer and occasional interval sessions.

Although the most recent of the three half-marathons that I have run in the past few years was the slowest on account of a quite debilitating illness lasting a few weeks about 2 months before the event, it was the most informative about my current physiological status because I was able to record times and heart rate for 1 mile splits using my relatively recently acquired heart rate monitor.

In light of my inadequate preparation due to the recent illness, I had started that race with the intention of maintaining approximately 8 min/mile to the half-way point and then if I was coping, increasing the pace in the second half.  The first half went well and I reached 6 miles in 47:10 (7:52 min/mile) according to plan.  I picked up pace in the seventh mile (7:22 min), but then a minor disaster struck – I tore a hip adductor muscle while turning abruptly. I was forced to limp awkwardly and it was clear that unless I could find some way of protecting the adductor, I would have to drop-out.  I spent the eighth mile experimenting and found that a shuffling gait with short strides and minimal airborne time alleviated the pain in the adductor.  Provided I increased cadence, I could achieve a reasonable pace.    By 9 miles I shuffling along at a pace faster than 8 min/mile, and managed an average of 7:55 /mile over the final 4 miles.  As I described in my blog posting a few days after the event, I threw caution to the winds and raced the final 200 metres – tearing a few more fibres in adductor but none the less, pleased that I had rediscovered a little bit of the fighting spirit of my younger days.

The Heart Rate Monitor revealed that my average HR over the entire race was 137 (87%  of my estimated maximum HR).  Most importantly, the monitor indicated that I had maintained this rate with very little drift.  For miles 2 to 6 I maintained a pace of 7:53 /mile and average HR of 137 ( 675 beats/Km).  Despite shuffling in an ungainly manner for miles 10-13,  I achieved a pace of 7:55 /mile, and average HR 139 (681 beats/Km).  In view of the inefficiency of the shuffle, the rise in beats/Km compared with miles 2-6 was trivial and suggests that I was capable of maintaining 87% of maxHR  for 13.1 miles without appreciable upward drift.

While I would expect a well trained runner to maintain a HR around 90% of maximum with minimal drift during a HM, I am pleased that my relatively low volume of training had got me to the level where I could maintain 87% of HRmax without appreciable drift.   It is perhaps reasonable to expect that with a modest increase in training volume, I could develop my endurance to the point where I can maintain 89 -90% of HRmax for 13.1 miles.   Thus I can expect to reduce my time by a few minutes, perhaps down to 100 minutes, simply by increasing endurance.  I am fairly confident that an increase in training volume will achieve this.

If I am to make any greater gains, I will have to increase my aerobic capacity.  In my experience, beats/Km when running in the aerobic zone over flat terrain provides a fairly reliable proxy estimate of aerobic capacity.  At first sight, my recorded values of 675 b/Km from 2-6miles and 681 b/Km  for miles 10-13 in the half-marathon appear creditable– especially as the RH half-marathon is run on a hilly course.  In fact these figures for beats/Km would probably match those of many sub-elite runners.  But there’s the rub.  These figures suggest to me that there is not a great deal of scope for further improvement in the aerobic capacity my slow twitch fibres.  Recent experience indicates that I might achieve around 620 b/km, but I suspect that it will be difficult to improve much further than that.  If I can maintain HR 140 b/min for 13.1 miles and it costs me 620b/Km, my half marathon time would be 93 minutes.

Of course if I can achieve 93 minutes within the next two years I will be extremely pleased with myself; in fact if I can get below 100 minutes this year I will feel quite content.  However the interesting question is whether or not 93 minutes for a half-marathon would be my absolute limit.  And if so, why is this so much slower than I was capable of 40 years ago?  Although I never raced a half marathon in my younger days, my marathon performances suggest I was probably capable of running a half marathon in about 70 minutes.

The immediate answer is that I am now limited by my maximum heart rate.  With a HRmax of 157, I cannot expect to maintain greater than an average of 140 b/min during a half marathon.  Even if I can increase aerobic capacity to achieve 620 b/km, my pace will be limited to 4:26 min/km.   HRmax generally declines with age and it is widely believed that it is not possible to increase HRmax by training.  My own experience confirms that aerobic training does not increase HR max.  In fact the greater my aerobic fitness, the harder I find it to achieve near-maximal heart rates.    However, in light of the observation that my muscle power has decreased markedly as I have aged, I wonder how much of the decrease in HRmax and my apparently creditable low ‘beats/Km’ during aerobic running can be attributed to the fact that I no longer have an adequate mass of muscle to recruit.

Speculation 

This leads to a somewhat speculative conclusion.  First of all, past experience suggests that with a moderate increase in training volume, especially with an increase in the number of ‘good aerobic’ tempo runs, I can get my type 1 (slow twitch) fibres into peak condition.  Because fortune appears to have blessed me with a fairly high proportion of type 1 fibres, I have a reasonable chance of running a creditable half marathon (and after another year or two of training, perhaps a similarly creditable marathon).  However I will be limited by my deteriorating muscle mass.  If I want to push back the limit, I need to increase muscle mass.  In practice, this means increasing type 2A (fast twitch aerobic fibres).

These considerations suggests that while having a high proportion of type 1 fibres provides a sound  foundation for running a fairly good marathon, to reach one’s peak potential, it is also necessary to have at least moderately well developed type 2A fibres.  So while my primary goal over the next few months is increasing the oxidative capacity of my type 1 fibres, I will also return to the challenge of building up type 2A fibres.

Getting high at the sweet spot

In response to my recent post about the sweet spot in the mind, Mystery Coach reported the very interesting comment by Alberto Salazar about his tremendous improvement when he took the antidepressant, Prozac. He reported that within a few days his running returned to a level that he had not been at for years.

In his response to my post, Ewen had described his experience of  a fairly ’sharp’ tipping point — he reported how he finds that when training his is going well, his mind is strong and he is enthusiastic to continue to improve the training. Then when he becomes tired for whatever reason, his mind weakens and he finds it hard to drag himself out of the slump.

I think this describes very well what happens when we train beyond the sweet spot.  The body’s distress signals, which include an increase in release of cortisol from the adrenal gland, triggers a depressive response that results in further increased release of cortisol creating a vicious cycle that tips us into a downward spiral   It is crucial that training produces a balanced strengthening of mind and body. If the body outstrips the mind, we become like Alberto Salazar when he was depressed – the mind prevents us achieving our potential.  If the mind becomes stronger than the body we risk serious injury to the body.

But what happens at the sweet spot?  Maybe the sweet spot is another term for the runners high.  This is often attributed to the release of natural opiods in the brain.  Maybe this can happen, it is not what I would describe as the ‘real runners high’ – the real sweet spot.

Memories of a balmy evening summer evening in Adelaide

I have a very vivid memory of one evening many years ago when I experienced the ‘real’ sweet spot and it did not feel in the least like an opium-induced deadening to pain. On the spur of the moment I had decided to run a 10,000m in a midweek evening meeting on the old Adelaide Harriers cinder track.  It was a small local meeting, but it provided one of the few local opportunities for a 10,000m on the track at that time, in the late 1960’s.  I arrived at the track late from work, and did not even have time to warm up, but perhaps the rush to get there on time had provided both the physical and mental warm-up I needed.  At the sound of the gun, I experienced a surge of energy and confidence.  By the end of the first lap I was leading.  In the second half of the race I was lapping runner after runner – perhaps not all that impressive because the old AH track only about 350m per lap, but I felt unstoppable   I do not have a record of my time when I breasted the tape – I wasn’t particularly interested in PBs in those days.  However I am sure that I had run at something near my usual 5000m pace; but instead of the pain that I was accustomed to experience in the final laps of a 5000m, the final few laps in that small local event on that balmy Adelaide mid-summer evening are among the most treasured of my running memories.

 Dopamine

Although I did not know anything about brain chemistry then, I am fairly sure that the dominant brain chemical that fueled that high was dopamine. In fact in the 1960’s the role of dopamine was scarcely known to science.  It had first been identified in 1958 by the Swedish neuroscientist, Arvid Carlsson.  He eventually shared the Nobel Prize in Physiology and Medicine in 2000 for his contribution to unraveling the mysteries of dopamine.  A few years ago,  I had a discussion with Professor Carlsson at a scientific conference during which he had described to me an experiment that he had performed on himself during his attempts to elucidate the role of dopamine in the brain.   He described how one evening he had been planning to play tennis with some friends after work, but in the early afternoon he had administered to himself a drug which drastically reduced the levels of dopamine in the nerve terminals of his brain.  The consequence was a total deadening of any enthusiasm for anything.  He descried graphically but simply how he had not turned up for the tennis match after work.  He simply could not summon the energy required.  I was reminded on my opposite experience on the Adelaide Harriers track many years previously, and I wondered what part the natural release of dopamine had played in my experience that evening.

There are artificial ways to produce a massive release of dopamine.  Both amphetamine and cocaine achieve their effects by promoting the release of dopamine in the brain.  This was demonstrated in the sad case of Tommy Simpson, who died at age 29, about 2 Km short of the summit of Ventoux during the 1967 Tour de France, as a consequence of using amphetamine together with brandy.

It is pure madness to interfere artificially with the normal balance of mind and body.  However, I suspect that one of the consequences of a well balanced training program is the natural development of a harmony between mind and body: a situation in which the physiological messages generated by physical effort – perhaps a combination of the effects of both adrenaline and cortisol – produce a surge of dopamine in the brain that enhances motivation and induces the central governor to allow even greater physical performance.  The details of this proposed mechanism are speculation, but my experience as both a runner and a neuroscientist incline me to believe that the core of the theory is not only plausible but probably true.

 

Conclusions 

If so, what are the practical conclusions? The first conclusion is that the goal of training is to produce seemingly effortless running.  There is little denying that training sessions should be hard, but the goal is construction, not destruction.  Perhaps the best interval session is a session where you know that you could have done yet one more interval even a little faster.  The best long tempo run is one where you could have maintained the tempo just a little further.   Because training sessions rarely have the buzz that comes with racing, a good training session should be harder than racing, but not that much harder.  And it must be followed by adequate recovery.  Leaving your guts on the training track too often is not the way to achieve the elusive sweet spot where mind and body work in harmony.