Hunger is your best friend: It makes natural foods taste delicious and promotes optimal nutrient partitioning

One of the biggest problems with modern diets rich in industrial foods is that they promote unnatural hunger patterns. For example, hunger can be caused by hypoglycemic dips, coupled with force-storage of fat in adipocytes, after meals rich in refined carbohydrates. This is a double-edged post-meal pattern that is induced by, among other things, abnormally elevated insulin levels. The resulting hunger is a rather unnatural type of hunger.

By the way, I often read here and there, mostly in blogs, that “insulin suppresses hunger”. I frankly don’t know where this idea comes from. What actually happens is that insulin is co-secreted with a number of other hormones. One of those, like insulin also secreted by the beta-cells in the pancreas, is amylin – a powerful appetite suppressor. Amylin deficiency leads to hunger even after a large carbohydrate-rich meal, when insulin levels are elevated.

Abnormally high insulin levels – like those after a “healthy” breakfast of carbohydrate-rich cereals, pancakes etc. – lead to abnormal blood glucose dips soon after the meal. What I am talking about here is a fall in glucose levels that is considerable, and that also happens very fast – illustrated by the ratio between the lengths of the vertical and horizontal black lines on the figure below, from a previous post ().

Those hypoglycemic dips induce hunger, because the hormonal changes necessary to apply a break to the fall in glucose levels (which left unchecked would lead to death) leave us with a hormonal mix that ends up stimulating hunger, in an unnatural way. At the bottom of those dips, insulin levels are much lower than before. I am not talking about diabetics here. I am talking about normoglycemic folks, like the ones whose glucose levels are show on the figure above.

On a diet primarily of natural foods, or foods that are not heavily modified from their natural state, hunger patterns tend to be better synchronized with nutrient deficiencies. This is one of the main advantages of a natural foods diet. By nutrients, I do not mean only micronutrients such as vitamins and minerals, but also macronutrients such as amino and fatty acids.

On a natural diet, nutrient deficiencies should happen regularly. Our bodies are designed for sporadic nutrient intake, remaining most of the time in the fasted state. Human beings are unique in that they have very large brains in proportion to their overall body size, brains that run primarily on glucose – the average person’s brain consumes about 5 g/h of glucose. This latter characteristic makes it very difficult to extrapolate diet-based results based on other species to humans.

As hunger becomes better synchronized with nutrient deficiencies, it should promote optimal nutrient partitioning. This means that, among other things: (a) you should periodically feel hungry for different types of food, depending on your nutrient needs at that point in time; (b) if you do weight training, and fell hungry, some muscle gain should follow; and (c) if you let hunger drive food consumption, on a diet of predominantly natural foods, body fat levels should remain relatively low.

In this sense, hunger becomes your friend – and the best spice!

London 2012: Kipsang & Keitany conquer London

Wilson Kipsang and Mary Keitany conquer the world's most competitive marathon

The London Marathon today wrapped up a spring marathon season that leaves the world's elite nicely poised for the next big Marathon, the London Olympic Games.  If I had to throw out one word that sums the last eight days of city marathons have shown, it's "patience".

2011 was the year that the Kenyans changed the marathon.  They made it look like a track race, destroying fields and racing their way to an astonishing collection of victories and records in every Major city marathon.  Rotterdam and Boston a week ago didn't follow the trend, and neither did London, at least in terms of course records, but it was still super fast - Mary Keitany produced the fastest marathon in the world this year, a Kenyan record, and the fifth fastest of all-time (mixed and women only races) with her exceptional 2:18:36.  Wilson Kipsang almost broke the course record, missing it by (for him) the now familiar time of four seconds in 2:04:44 (you'll recall that Kipsang last year missed the world record by the same margin).

However, their performances are noteworthy for the entirely different manner with which they were achieved.  And it is Kipsang's, or rather the men's race, in particular, that is particularly noteworthy for how it has reminded us of the theme of 2012 - the marathon has struck back.  If 2011 was the year when the Kenyans turned marathon running into something of a prolonged track race, then 2012 is the year when the marathon has reminded us all that it's still a race that requires control, patience and a good deal of respect for how effort is 'spent' over its distance.  An analysis of the men's race illustrates this nicely, and comparison with Keitany's victory further emphasizes this point.

Let's look at both races, starting, for a change, with the women's race.

Keitany - patience and building to an extra-ordinary final 15km


Keitany's record breaking day was built off an extra-ordinary second half after a patient first half.  The last time we saw Keitany in a marathon, she was going backwards in New York after starting at World Record pace.  She would later describe how she felt better than she really was, and followed that feeling to what was really a suicidal pace, for which she paid but still clung on to third place.

There was no early suicidal pace in London today, but she was responsible for a murderous pace at the end, as Keitany ran a perfect marathon against arguably the strongest field of women ever assembled.  Halfway was reached in 70:53, projecting a 2:21:46, which was, at the time, fairly slow given the quality of the field.

It wouldn't remain slow for long, and the graph below, showing Keitany's 5km splits (blue line), illustrates just how the pace ramped up from halfway onwards.  It wasn't the same dramatic surge that we saw from Keitany in 2011 (the red line), where she attacked at halfway and reeled of a 32:10 10-km interval (67:52 half marathon pace), but it would end even more spectacularly, as Keitany ran the second half in 67:43!  And that was with a progressive acceleration, as the graph below shows.

Unsurprisingly, the rest of the women's field was being stretched out by Keitany's pace.  A lead group that consisted of 8 was cut progressively after halfway, and ended up being four women with 10km left to run, the Ethiopian challenge dealt with by 30km.  That's when Keitany's pressure at the front really began to tell, and Florence Kiplagat and Priscah Jeptoo dropped off the back.  This left Edna Kiplagat as Keitany's sole challenger, but Keitany never wavered.  She didn't appear to do anything spectacular - unlike in the men's race, there was no single kilometer that did damage, but rather a gradual winding up of the pace.

That segment from 35 km to 40 km was covered in 15:45, and is the fastest 5km segment ever recorded by a woman in a major marathon (Paula Radcliffe's fastest was a 15:47 opening 5km back in 2005).  By virtue of that interval, Kiplagat's challenge was broken, and the world champion fell back by 40 seconds over this interval alone.  She would eventually hang on to finish in second, with a sub-2:20 of her own, but Keitany just got faster and faster.

Some other extra-ordinary stats about Keitany's second half are:

• The final 12.2 km were clocked at 38:43, which is 31:44 pace for a 10km
• The final 7.2 km were run in 22:35, which is 31:22 pace for 10km
• Her final 2.2 km were timed at 6:50, which is 3:06 per kilometer

The circles in the graph above show Keitany's time gap in 2012 compared to last year's 2:19:19 victory.  You can see that the pace early was slower - 34 seconds lost in the first 5km, then another 8 to 10km and so on.  At the 30km mark, Keitany was 42 seconds slower than in her 2011 victory, but then she started to move.  The 15:45 "record" interval took her ahead of last year's time, and then she closed out the final 2.2km in an incredible 6:50, to run 43 seconds faster than in 2011 (not shown on graph).

The 6:50, incidentally, was better by only three other athletes on the day - Wilson Kipsang who won the men's race, and ran 6:45, and then Martin Lel and Tsegay Kebede who sprinted the finish straight on route to a 6:37!  Keitany was simply untouchable in this strongest women's race ever.  What this does is set up the Olympic Marathon beautifully, with Liliya Shobukhova awaiting Keitany.  Shobukhova last year won Chicago in 2:18:20, and is the only athlete faster than Keitany in the last 7 years but has been beaten by Keitany (London 2011).

Radcliffe, of course, has run faster than both, but there are serious doubts over her ability to produce anything like what we saw today, and it seems that that is what it will take to beat Keitany, who has now shown herself to have learned the marathon and has the pedigree to win Olympic Gold for Kenya.

As a final word, it's interesting to note that the spectacular 67:43 second half by Keitany is still slower than Paula Radcliffe's second half during her 2003 run.  In that race, after going through halfway in 68:02 (2:51 faster than 2012), Radcliffe ran the second half in 67:23!  Testament to the quality of that performance.  But, Keitany's final 10km is the fastest ever for a woman marathoner, as our friends at Letsrun.com have written.

Men's race: Wilson Kipsang wins a race of attrition with an incredible mid-race surge

Now let's look at the men's race, and keep that graph of Keitany's in your mind - she started patiently, ran a steady first half and then got faster and faster, culminating in a record 5km interval from 35km to 40km.

Wilson Kipsang did it differently.  In the men's race, it was all about aggression early.  Not in the first half, because like in the women's race, that was fast but evenly paced.  They hit halfway in 62:12, after 5km segments of 14:36, 15:00, 14:54 and 14:43.  You can contrast this with Emmanuel Mutai's 2011 course record, where halfway was reached in 62:44.  So it was fast.

And then it got faster.  Wilson Kipsang, at least from TV pictures, seemed to be the main aggressor, and as the race reached the halfway mark, he blew it wide open.  The splits would later reveal why - the 5km segment from 20 to 25km was run in a spectacular 14:09.  That's one of the fastest 5km segments ever measured in a world class marathon (Wanjiru in London 2009, Mosop in Chicago 2011 are faster), and it was responsible for creating massive gaps in an incredible men's field (Geoffrey Mutai ran a 14:12 segment in Boston in 2011).  This meant that London 2012 produced the fastest 5km splits for both men and women, though for Keitany, this came at the end, for Kipsang, the middle...

Kipsang was followed, at first, by Worku and Lilesa of Ethiopia.  Abel Kirui was a little slower to respond, but he did bridge the gap, and by 25km, he had replaced Worku in the front three. From 25km to 30km, Kipsang, Lilesa and Kirui continued to work hard on the front, growing the lead over the chasers, who included former champions Tsegay Kebede, Emmanuel Mutai and Martin Lel, to just over 1 minute.  At this stage, the front three looked assured of podium places at least, and it was Kirui who did most of the front running between 25km and 30km, looking very strong and full of running.

Then, the next time we saw the race at around 33km, Kipsang was clear, so a split happened somewhere at about 32km.  The gap at 35km would grow to 15 seconds, and it was created entirely because Kirui and Lilesa's pace dropped, and not by a surge by Kipsang.  In hindsight, this small gap of 15 seconds at 35 km was the first symptom of an impending implosion for both Kirui and Lilesa.

The graph below shows the 5km splits for Kipsang and Kirui (red and green, respectively) as well as Mutai in 2011.  You can see that having been locked together up to 30km, Kipsang held the pace at 14:42 and then 14:43 per 5km, whereas Kirui and Lilesa, still together at this stage, slowed down to 15:00/5km pace.  That was enough to put Kipsang clear, and even though he would also slow down, running a 15:11 from 35km to 40km, his lead grew, because Kirui and Lilesa were going backwards by this stage.

The best illustration of Kirui and Lilesa's difficulties comes from a comparison with Lel and Kebede in the chase.  At 30km, the gap was 1:02, and Kirui and Lilesa were locked in battle with Kipsang.

By 35km, Kirui and Lilesa had lost 15 seconds to Kipsang out in front, but their lead over the chasers had grown to 1:42.  Then it started to come down, steadily at first, then precipitously.

By 40km, Lilesa was only 18 seconds ahead of Lel and Kebede.  He therefore lost 1:24 of his lead within 5km.  Kirui was still hanging on, 51 seconds ahead, so he had lost 51 seconds over the same period.

Then over the final 2.2km, things went particularly badly.  Lilesa took 8:24 for the final 2.2km and went from third to tenth, whereas Kirui ran the final 2.2km in 8:33 and dropped from 2^nd to 6^th.  After losing 51 seconds over the 5km from 35 to 40km, Kirui then lost an additional 1:56 over the final 2.2km.  Partly, this is because he shut it down after being caught, but with prize money at stake, his and Lilesa’s final 7km illustrate how costly the mid-race aggression was.

Kipsang meanwhile was holding the speed a lot better – having run 14:42 and 14:43 between 25 and 35km, he dropped to a 15:11 from 35km to 40km, and then ran just outside 3 min/km to the finish.  Having been ahead of Mutai's record pace from about 16km (see circles in the graph above), Kipsang then drifted outside and just missed the course record, which, it must be said, he probably deserved for the manner with which he beat such a strong field by such a large margin.  

In some respects, this London race was similar to what we saw in Boston last week, with those involved in big mid-race surges paying dearly for it at the end.  It's a lesson in "cost-benefit" analysis of marathon running and pacing!  The difference between London and Boston, of course, is that in Boston, the eventual winner Wesley Korir was very conservative and did not get involved in surges, whereas London was ultimately won by its main aggressor in Kipsang.  However, for Kirui and Lilesa, London 2012 was the same as Boston was for the likes of Levy Matebo and Matthew Kisorio - mid-race aggression has a cost, and the marathon makes sure that cost is paid!

The margins between great and imploding - a fine line

The lesson then, is that the East African strategy of racing the marathon aggressively soon after halfway may exert a heavy price, one that has always existed but that we didn't notice too much when records were falling left, right and centre in 2011.  Today, it was a 14:09 split for 5km that blew the race open, gave Kipsang the victory, but also saw world class runners reduced to speeds of just faster than 4 min/km for the final 5km!  In Boston, the heat made this effect even more pronounced, but it's a lesson in how fine the margins are between extra-ordinary and "mortality".

Today, in London, Wilson Kipsang lived on that line, and managed to produce 'extra-ordinary', winning by 2:07.  Mary Keitany ran under that line until the time was right, and then she produced something truly extra-ordinary.  But for others, like Kirui and Lilesa, the line was too fine and they crossed it and paid.  Having been blown away by the "ease" of the Kenyan dominance of 42.195km in 2011, we are reminded how easily things can go wrong.

For Kirui, then, London was not a good day out.  Had he been more cautious, perhaps not followed the 14:09 surge, he might have come through strongly and finished second, far closer to Kipsang.  These men are racers, however, and are not interested in steady and conservative efforts to finish second when winning is an option, and this makes marathon running so enthralling.  However, Kirui paid for this today.

And the result, his sixth place, means the Kenyan selectors now have to take a "risk" picking him.  The same is true for Lilesa.  Instead, Wilson Kipsang looks to have secured his spot, and now it's a judgment call for the other two places.  Do the Kenyan selectors go with the beaten Mosop and Kirui?  Or do they pick the non-finishing champions of 2011 in Geoffrey Mutai and Patrick Makau? (who bailed at 16km, reportedly with a leg injury).  That's the next big marathon story, and then come the Games, and the clash between Kenya's best three and Ethiopia's best three.

2012 - deep high quality year, despite the lack of records and attritional nature

A final word - despite the 'slow' Boston performances, and despite everyone but Kipsang being made to look a little more mortal today and over the last few weeks, 2012 is still on course to be the strongest year ever for marathon running in terms of depth of performance.  Kipsang's 2:04:44 today was the seventh sub-2:05 time this year, which equals the 2011 record for most sub-2:05s.

It was also the 14th time under 2:06 in 2012, and that is the highest in history.  So while we haven't seen the course records and clusters of men racing to these times in the Major Marathons, we're still seeing the continuation of a revolution in the marathon.  It's just not quite as spectacular as it was in 2011.

Among the women, incidentally, the same is true.  Keitany and Kiplagat went under 2:20 today, making them numbers 5 and 6 this year, the most ever.  Twelve women have broken 2:22 this year, and that's also a record.

Of course, both the men's and women's stats have been helped by that Dubai race in January, where basically half these times were recorded.  So the stats are a little skewed, because outside of Dubai, the Major City Marathons haven't been as spectacular, but history will go on to record 2012 as the deepest year in marathon running, and we're only in April!

That's it for the Spring Marathons.  Busy time, as always, but hopefully you enjoyed the coverage, both here after the race, and also over on Facebook and Twitter.  I don't usually ask, but since it's the end of the season, if you'd like to make a donation to support The Science of Sport and our efforts at sports analysis, please do so at the button on the top right of the page (click here if reading this as an email to be taken to the site)

Until the next big event, which I'm sure is not far away!

Ross

Oh, and one final thing - it was great to see Martin Lel sprinting to the finish to claim second place today.  Lel, a past champion in London and New York, was the great marathon runner a few years ago, but injury, and perhaps age, have caught up with him, and this was something of a surprise return.  He was my favourite marathon runner in around 2007, 2008 and his sprint finish at the end of marathons one of the great sights in running - remember his kick off the final bend to win London in 2008?  Today was a moment of nostalgia.  Lel isn't in the Kenyan squad, he wasn't named to the six man shortlist, but my impartial opinion is that if it was a slow race, I'd have him in it, fitness allowing!

Olympic Games: 100 days to go

The Olympic Games: 100 days to go

One of the best things about the rapidly approaching Olympic Games is the discussion it provokes about the giants of their sports, who have often been quiet for a long time, but emerge for the Games.  Bekele seems back, and how does that affect Mo Farah and Galen Rupp's chances?  The suspense builds.  Usain Bolt blitzed an anchor leg in a 4 x 100m relay last weekend, and then watched Yohan Blake run an impressive 9.90s season opener - the suspense builds.  Paula Radcliffe wasn't as impressive, running 72:03 in a Vienna Half Marathon, the slowest time of her professional career, though it did come off a bout of bronchitis.  And then there's Semenya, Pistorius (for us in SA, anyway), Wariner, and pretty soon, once the Diamond League kicks off in Doha on May 11, a host of other matchups to speculate about and analyse.

Then there's swimming, with Phelps vs Lochte top of mind for now.  There's tennis and the prospect of a grass court Olympic gold, triathlon and a Brownlee vs the rest battle, and many other stories waiting to be written.  And with 100 days to go, all that discussion will accelerate.

So here, to commerate the 100 day countdown, is a video dating back to before Bejing 2008, featuring some of the legends of the Olympic Games.  Beijing gave us a few athletes who belong in this clip, but then there are 100 days to update it!

Ross

Boston strikes back: The Boston 2012 meltdown

Boston strikes back, as Kenya claim a double on a brutal day

Wesley Korir and Sharon Cherop have won the 2012 Boston Marathon for Kenya.  Surprise names, perhaps (particularly Korir), but you might, at first glance, call it "just another Kenyan victory".  It was anything but.  Today was a reminder of the difficulty of the marathon, because Mother Nature, so kind to Boston one year ago, decided to strike back and show the other extreme of marathon running.  The winning times - 2:12:40 for Korir and 2:31:50 for Cherop, are a staggering 9:38 and 9:14 slower than last year's winning times respectively.  That's almost 19 minutes, collectively, and we were today reminded that even the great runners are "mortals" in the face of tough conditions.

The timing from Boston tells of three races, and it's too tempting not to compare.  There was Geoffrey Mutai of 2011 - the astonishing 2:03:02 performanced, aided by a strong following wind and ideal temperatures of around 50F.  Then in 2012, there were Wesley Korir and Levy Matebo, who finished first and second, but ran two quite different races, and their paces tell the story of the day.

So here are three thoughts about Boston 2012, including some insight on the physiology of the various "meltdowns" we saw today, and how Wesley Korir and Jason Hartmann got it just right:

1.  Caution counts when conditions make the margin for error smaller


We are so used to seeing aggressive racing by the Kenyans.  Surges and brutal accelerations have given them countless titles, in addition to super fast times.  Today in Boston, with the mercury rising above 80F and in bright sunshine, fast times were never going to happen, but the racing surges in the second half were going to decide the title.

And sure enough, in both races, the early pace was super slow.  The women went through 15km in 55:15 - that's a full 5:06 slower than the 2011 equivalent.  The men hit 15km in 46:48, which was 3:03 slower than in 2011.  So the first half was conservative, as one might have predicted (though even I was surprised at how conservative it was).  The women's projected time was 2:35 until late racing brought it down, whereas the men didn't dip below 2:11 from the 10km mark onwards.

Shortly after halfway, the attacks began, particularly on the men's side.  Matthew Kisorio went off the front just after 25km, and Matebo and Geoffrey Mutai followed.  A few small attacks followed, the field regrouped and then split again, and it was Matebo, Kisorio and Mutai once again at the front.  Then Mutai dropped back, and fell precipitously off the pace - having been in the lead pack at 27km, he was 1:22 down at 30km and it was clear that his race was run.  He dropped out shortly afterwards, and the talk is that he was suffering from cramps.

Then it was Kisorio's turn to crack.  He led at 30km, was the aggressor responsible for the early attacks, but shortly before 35km, he began to drop off the pace (10 seconds down).  From 35km to 40km, he absolutely blew, running that 5km stretch in 19:06, before eventually finishing in 10th with a final 2.2km of 10:13 (4:39/km pace)!

So that left Matebo, who had also mixed it among those surging at 25km.  He held out longer, but his time was also coming.  Having built a handy lead at 35 km (10 sec to Kisorio who was going backwards, and 57 seconds to third place, he 'melted' between 35km and 40km, covering this stretch in 16:40!  The result was that he was reeled in by Korir, who would eventually pass him for the win.  To his credit, Matebo hung on, even counter-surging at 40km when caught, but it was to no avail for the win, but he did hold onto second place.

And then there was Wesley Korir.  He did not get involved in the surges, but ran a very solid and constant pace.  He was the benefactor of his patience, because when the three ahead of him were blowing and bailing and slowing dramatically, he was able to pick them off by running pretty much the same pace the whole way.  It was a lesson in even pace, and it highlights the risk of the aggressive surging strategy that the Kenyans adopt.

The problem, physiologically, is that these surges are metabolically costly.  And therefore, they are also very challenging from a thermoregulation point of view.  Repeated sprints, for example, are one of the best ways to drive your body temperature higher, and while these men were not exactly sprinting over and over in the marathon, the mid-race surges do more or less produce this result - body temperature climbs and perhaps more importantly, thermal comfort and perception are hugely affected.

Now, on a "normal" day, this is not a huge problem - body temperature and thermoregulation are not crucial factors, and the world's best are able to recover quickly from the metabolical cost of the surge.  The physiology of thermoregulation is different - you can't just suddenly lose heat, and so the cost of the higher intensity is paid out over longer periods, taking much longer to recover from.  As a result, the line between "just right" and too fast is extremely narrow, and a typical attack is now the one that breaks the aggressor and not just the rest of the field.  Therefore, success comes to those who avoid the variations in pace and the harder efforts, and that's what Boston showed today.

Take a look at the graph below - I spoke earlier of three races.  We compare the 2011 Mutai performance (blue line), the race run by Levy Matebo (red line) and the winning performance from today of Wesley Korir (green line).

The circles at the bottom show just how far off last year's pace the race was at each 5km interval - 54s down at 5km, another minute lost to 10km, and so forth. By 25km, for example, this year's race was almost 5 minutes slower than Mutai's last year.  Then came the "surge" from Kisorio and Matebo, between 25km and 30km.  That surge led to the only 5km split of the 2012 race that was faster than 2011 - 14:59 for Matebo vs 15:07 for Mutai last year (the green circle, - 8 seconds).

But notice Korir's pace line in green - he didn't respond to that increase in pace.  He held his pace at between 3:05 and 3:10/km, much as it had been for the entire race, and lost contact, falling to sixth overall.  That continued to 35km, where he conceded another 18 seconds, but was now up to third as those who had been sucked into the attacks paid for it.  Then, from 35km, he started to reel them back.  His split from 35km to 40km was 15:44, and while that's not fast in absolute terms, it was the fastest of the race for that segment.  Meanwhile, Matebo was exploding up ahead, running the same stretch in 16:40, and the two were together at 40km.

Not surprisingly, Korir had more in reserve, and closed the final 2.2km in 7:13.  That too was the fastest of the race, whereas Matebo finished with a 7:39.

On the women's side, the pace barely deviated.  It began slowly at 3:46/km, and while it got faster, it was a race mostly lacking in real attack.  Sharon Cherop was aggressive at the front, but it was a grinding win, and she just ran everyone off systematically, until she made one final, decisive move with 800m to go.  It would be terrific to see 1 km splits (normalised for the hilly profile), to see whether the men's race was more variable (I suspect it was considerably so).

The moral of the story is that on a hot day, the even paced approach works and is vital, and today, the Kenyan strategy of attacking and surging was very costly indeed.  One final illustration - Jason Hartmann of the USA, who had a great race to finish fourth.  He took the "Korir approach" of not responding to the attacks at 25km.  The result was that he actually dropped out of the top 10 at 25km, but then began to claw his way back up, by virtue of some really even pacing.  His 5km splits from 25 km to the finish were: 16:03 - 16:13 - 16:22, with a final stretch of 7:30 (second fastest in the race).  Remember, this came at a time when those early leaders were running 16:40 (Matebo), 18:01 (David Barmasai), and even 19:06 (Kisorio)!

The heat makes it good to be something or a tortoise!  Or at the very least, an even paced hare!

2.  Conditions really matter.  And Boston today was brutally, $%&#ing hard

There was a lot of talk about the temperature before the race, many people panicking about the imminent death and danger the runners would face.  I think it's largely overhyped in terms of safety, but today did illustrate just how important conditions are for fast racing and performance.  Today's races were 7.8% (men) and 7.0% (women) slower than last year, and that's partly the heat, partly the lack of wind, but it goes to show how "fragile" performance is when you're trying to race for 2:05 or faster.

That's why talk of a sub-2 is so premature.  Even if the athletes are in ideal physical condition, it needs environmental factors to be absolutely perfect to allow it.  And this idea that these African athletes are so special that they can just break down the physiological barriers is a fairytale.  They're exceptional, make no mistake, but barriers are real and if conditions are not perfect, no "belief" or lack of limitation overcome sub-optimal conditions.

Back to Boston - today we saw a day when a mid-race attack at 3:00/km was enough to create gaps of over a minute within 5km!  It was a day where running at 15:30 per 5km pace was splitting a world class field full of 2:06 men.  That's a brutal day.  And while it wasn't that hot, I think one can't overstate the impact that direct sunlight has on thermal load and challenge.

Recently, when I was putting myself through my little barefoot Kilimanjaro experiment, it became clear that direct sunlight exerts an effect on temperature and thermal comfort that is far greater than we acknowledge.  The only reason I was able to summit Kilimanjaro barefoot in air temperatures below freezing point was because the African sun did a magic job heating the ground up.  At one point, at 4,700m altitude, the air temperature was -3 degrees celsius, and the ground was 20 degrees celsius!

Now the opposite implication was true for Boston today.  Temperatures in the shade were reported at around 82F, but in the sunlight, which is most of the race, they would have been 10 to 15 degrees higher.  The result is an effective temperature closer to 95F, and that's the difference between today in Boston and Beijing 2008.  There, Sammy Wanjiru apparently defied physiology and physics to run 2:06:32 in the heat and humidity (I say 'apparently' because that kind of performance does not defy anything - you can model it as entirely possible given his mass and the pace).  But it was, I believe, cloudy, and I think that's a crucial difference, especially in a city surrounded by buildings.

So Boston 2012 provided all the elements of a war of attrition, and 2:12 and 2:31 winning times for men who run under 2:06 and women who run 2:22 is evidence of it.  It doesn't make for the same kind of awe as we had one year ago, but perhaps it's a much needed reminder of just how remarkable a 2:05 marathon is, now that it seems so "common-place"!

3.  Kenya have bigger selection problems after this weekend

Final point, a short one.  What would you do as a Kenyan selector after this weekend?  You've seen the Ethiopians respond to your amazing 2011 by producing five sub-2:05 performances in 2012 so far.  They occupy five of the top six spots in the world rankings, and have beaten one of your stars in Rotterdam.

Another one of your champions, perhaps the best of them, has failed to finish a race in Boston, and while it's a freakish race because of the heat and you can take some consolation that at least other Kenyans dominated, you now have a major dilemma on your hands!  Do you pick Mutai, 2011's best racing marathon runner by virtue of wins in unpaced Boston and New York?  Do you write Boston off as a "bad day", an anomaly?  Because if you do that, then Mosop's 2:05:02 in Rotterdam may also be a "bad day"...

And what happens in London may complicate life further.  If that's an ideal day, and four or five Kenyans break 2:05, then a difficult decision becomes almost insoluble!  Time to draw straws!

Personally, I'd pick Mutai, because 2 out of 3 race wins, and the manner of those wins in 2011 mean that his pedigree is unquestioned.  Plus there is his cross-country pedigree, and Boston 2012, much like Boston 2011, may be races to write off as once-in-a-lifetimes...

Oh, and finally, spare a thought for Michel Butter of The Netherlands.  He was using Boston to try to qualify for the Dutch Olympic team.  His requirement was either to run 2:10, or finish in the top 8 with a 2:12 or faster.  He ran 2:16:38 for 7th.  So he got the place, but missed the time, and hence the Olympic spot.  That's a bitter pill to swallow, because as I mentioned earlier, the elite men were 7.8% slower than last year's times, and about 5% slower than their typical race times. Butter missed the target time by 5.1% (the 2:12 standard).  Bearing this mind, and that Boston is typically a slower course than the flat races of Rotterdam, London, Berlin etc, I would use discretion and pick him anyway...

And then to anyone else hoping that Boston would help them to a PB or selection, 2013 is another year.  Perhaps Nature will be kinder again!  I'd say that she owes Boston a good day, but then again, this may have been payback for 2011!

Finally, if you missed it, and want to follow my "blow by blow", "meltdown by meltdown" coverage of the race on Twitter, check it out here.

I'll do the same thing for London on Sunday - live updates and splits throughout the race, so join us on Twitter if you haven't already done so!

Ross

Hormonal reductionism is as myopic as biochemical reductionism

Biochemistry-based arguments can be very misleading. Yet, biochemistry can be extremely useful in the elucidation of diet and lifestyle effects that are suggested by well-designed studies of humans. If you start with a biochemistry-based argument though, and ignore actual studies of humans, you can easily convince someone that glycogen-depleting exercise (e.g., weight training) is unhealthy, because many health markers change for the worse after that type of exercise. But it is the damage caused by glycogen-depleting exercise that leads to health improvements, via short- and long-term compensatory adaptations ().

Biochemistry is very helpful in terms of providing “pieces for the puzzle”, but biochemical reductionism is a problem. Analogous to biochemical reductionism, and perhaps one example of it, is hormonal reductionism – trying to argue that all diet and lifestyle effects are mediated by a single hormone. A less extreme position, but still myopic, is to argue that all diet and lifestyle effects are mostly mediated by a single hormone.

One of my own “favorite” hormones is adiponectin, which I have been discussing for years in this blog (). Increased serum adiponectin has been found to be significantly associated with: decreased body fat (particularly decreased visceral fat), decreased risk of developing diabetes type 2, and decreased blood pressure. Adiponectin appears to also have anti-inflammatory and athero-protective properties.

As a side note, typically women have higher levels of serum adiponectin than men, particularly young women. Culturally we have a tendency to see young women as “delicate” and “vulnerable”. Guess what? Young women are the closest we get to “indestructible” in the human species. And there is an evolutionary reason for that, which is that fertile women have been in our evolutionary past, and still are, the bottleneck of any population. A population of 100 individuals, where 99 are men and 1 is a woman, will quickly disappear. If it is 99 women and 1 fertile man, the population will grow; but there will also be some problems due to inbreeding. Even if the guy is ugly the population will grow; without competition, he will look very cute.

Jung and colleagues measured various hormone levels in 78 obese people who had visited obesity clinics at five university hospitals (Ajou, Ulsan, Catholic, Hanyang and Yonsei) in Korea (). Those folks restricted their caloric intake to 500 calories less than their usual intake, and exercised, for 12 weeks. Below are the measured changes in tumor necrosis factor α (TNF-α, now called only TNF), interleukin-6 (IL-6), resistin, leptin, adiponectin, and interleukin-10 (IL-10).

We see from the table above that the hormonal changes were all significant (all at the P equal to or lower than 0.001 level except one, at the P lower than 0.05 level), and all indicative of health improvements. The serum concentrations of all hormones decreased, with two exceptions – adiponectin and interleukin-10, which increased. Interleukin-10 is an anti-inflammatory hormone produced by white blood cells. The most significant increase of the two was by far in adiponectin (P = .001, versus P = .041 for interleukin-10).

Now, should we try to find a way of producing synthetic adiponectin then? My guess is that doing that will not lead to very positive results in human trials; because, as you can see from the table, hormones vary in concert. At the moment, the only way to “supplement” adiponectin is to lose body fat, and that leads to concurrent changes in many other hormones (e.g., TNF decreases).

Trying to manipulate one single hormone, or build an entire health-improvement approach based on its effects, is myopic. But that is what often happens. Leptin is a relatively recent example.

One reason why biochemistry is so complex, with so many convoluted processes, is that evolution is a tinkerer that is “blind” to complexity. Traits appear at random in populations and spread if they increase reproductive success; even if they decrease survival success, by the way ().

Evolution is not an engineer, and is not even our “friend” (). To optimize our health, we need to “hack” evolution.

Boston Marathon: if you can't stand the heat...

The heat and fear doctrine of the Boston Marathon

Later today, Geoffrey Mutai will attempt to address the Ethiopian dominance of marathons so far in 2012 when he defends his title in Boston.  Last year, aided by a following wind for most of the race, Mutai and Moses Mosop stunned the world when they scared the 2:03-barrier in Boston, Mutai eventually winning in the astonishing time of 2:03:02.  

The other factor that enabled Mutai's incredible time last year was the ideal temperature for the race - 50F.  This year, it will be a little different.  The forecast for Boston is temperatures in the 80s (that's 25 to 28 celsius), and it's caused a real panic among organizers, media and runners.

The Boston Marathon organization have recently issued a statement which has advised runners to consider their decision to participate.  That is, they are so worried about the heat (all 27 degrees of it) that they are telling people rather to stay away, especially if they are not heat adapted or accustomed to running in the heat (which is physiologically valid advice).  

Now, I can partly appreciate this - as we've seen many times with things like footwear and hydration, common sense is sadly uncommon, and the race organizers would usually bear the brunt of any mishaps that occur as a result of the heat.

And if you read the statement issued by the medical directors of the Boston Marathon, it is well balanced and addresses the key issues.  It emphasizes the most important point, which is that this will not be a day for record times or personal bests, whether you are Geoffrey Mutai or a runner trying to break 3 hours, or even 3:30.  In fact, these slower runners will probably be more affected than the elites, as the statement acknowledges.  Therefore, common sense dictates that anyone running in Boston accept the heat as a factor they can't control, adjusts their pace and still finishes safely.  

Easy solution.  No need to panic.

The day after tomorrow

However, the reaction from elsewhere is a little less sensible.  It reminds me of a Hollywood blockbuster like "The day after tomorrow" where the high temperatures are closing in and the citizens are running for the hills because of the "death sentence" that the heat must be.  

Some of the advice being given to runners is unnecessary and will only over-emphasize the risk of the conditions, when there is a really simple set of guidelines that runners should heed.  The biggest concern will be around dehydration and its supposed link to heatstroke.  People are freaking out that they'll lose so much water that their bodies will incinerate them from within, as is the general perception, I have to say, within the USA.

The advice that will have been thrown around at the Boston Expo, in the local papers, and among runners and their coaches is that it's essential to "drink as much as you can", and to "drink early, drink often, and drink plenty".  This is the most dangerous advice that can be given.

Replacing one problem with a more serious one

The problem with this fear of dehydration is that all it has done is to create a new problem, far more dangerous and lethal for runners.  This problem is called hyponatremia, and it happens because people overdrink during exercise.  They replace more than they sweat, and the result is that they dilute their body's sodium level (hypo = low, natremia = sodium).  This condition, if severe enough, leads to coma and death, and has claimed far more lives than any dehydration-related condition ever will.

Most of these deaths, incidentally, are in US marathons because that's where the pre-occupation with dehydration exists.  About a decade ago, an Ironman race in New Zealand suffered from an incredibly high number of hyponatremia cases.  In response, organizers did a little research, discovered that the cause was overdrinking, and the next year, they cut back on the number of water tables available, advised runners NOT to drink unless they were thirsty, and the result was no hyponatremias and no hospitalizations.

Boston has produced perhaps the most famous case of hyponatremia in Cynthia Lucero, who died in 2002 as a result of overdrinking, after she followed the advice given to her through all manner of sources, including the race, the magazines, the experts.  

Sadly, it's such an avoidable condition, because all it takes to avoid the risk is drinking to thirst.  If you drink to thirst, you cannot possibly develop hyponatremia during exercise, whereas if you attempt to force hydration, or to follow a schedule, then you put yourself at risk.  And the problem for Boston 2012, is that all the advice being given to runners is to drink, drink, drink, and it will create a problem for their medical team that is far greater than any risk of dehydration was going to be.

Dehydration and heatstroke - no evidence, and dehydration is normal

A note on dehydration - there's no evidence at all that links dehydration to heatstroke.  In fact, there is very little evidence on heatstroke either.  There are some documented cases of heatstroke, but they point towards unnaturally high rates of heat production, and not dehydration, as the cause.  Other cases of heatstroke have been found to occur in cool conditions, very early on during races, and therefore not linked to the environment or dehydration in any way.

The reality is that it is absolutely safe for humans to lose fluid during exercise.  We have an adaptation that allows this, because when our survival depended on our ability to hunt, we did not have the option of stopping every 10 minutes to drink a Gatorade, and so we are delayed drinkers.  We tolerate losing fluid very safely, and then we replace it later on.  Our research from Ironmans, Comrades and Two Oceans Ultra Marathons (90km and 56km, respectively - long enough to see problems if there were any), has shown that the vast majority, and we're talking 90% here, of finishers will lose between 0% and 3% of their body mass during a race.  

And these people, I must emphasize, are absolutely fine.  They've started a race weighing 180 lbs and ended it at 176 lbs, for example.  By the evening, they've replaced that fluid and are safe.  The ones we worried about were those who had not lost weight, or even gained.  These were the people who had taken on too much fluid, and needed to be hospitalized because they were seriously ill.

But again, to stress - dehydration is normal, it is safe to lose 2% of your body weight, or even 4%, 6%.  In fact, the race winners will have lost the most weight.  There are cases of race winners losing between 6% and 8% of their body mass, and they are absolutely fine, no complications other than being tired from the exertion.

The ultimate message here is that if we drink to thirst, we may lose fluid over the course of the race, but this is normal, and it is safe.  What is unsafe is forcing fluid intake, developing a schedule that doesn't allow for the impact of intensity and environmental conditions on our sweat rate.  Or taking generic advice that says, for example "Your body needs at least 1,200 ml of fluid per hour".  That kind of advice, however well-intentioned, could be a recipe for disaster, and the concern for Boston 2012 is that this is the message that people are now hearing.

The pace - expect a slower race, whoever you are

Then the other key thing for Boston is the pace, and the impact that higher temperatures will have on it.  It's really simple - when it is hot, you will run slower.  The elite athletes will get this right - they will start the race at a slower pace, and you won't see a halfway split of 61:30.  

We know that this happens because our body is smart enough to anticipate the future physiological consequences of our "actions", and so when it is 27 degrees and we run at 2:58/km, we generate heat but fail to lose it, and the body is able to work out that this is not going to produce an optimal result.  Why not?  Because once our body temperature hits about 40 degrees celsius, we stop.  Our brain, once that hot, doesn't recruit as much muscle, and the pace would be significantly reduced as a result.  

Over-riding regulation and running to the clock - it's all about perception

The problems happen when this regulation is over-ridden.  And this is why the Boston Marathon Association are warning people, because a lot of people will run "to their watch".  They'll have worked out that they can run 3:20 if they hit certain targets along the way, and they'll try to do this, regardless of conditions.  

It is these people, the ones who are inflexible and who race to a schedule, who run into trouble.  They don't get heatstroke is 99.9% of the cases,  but they feel terrible.  They feel incredibly hot, because their body temperature has probably been driven up towards 39 or 40 degrees celsius by the 25km mark of the race, and their perception of effort is so high by that stage that they think they're close to death! (read this review for full discussion of why the perception of fatigue is so crucial)

It's this perception that knocks them out, and may put them into the medical tent.  For all but a very tiny minority, that's the end of it, and all they need is rest and some cooling and they're fine, because there's actually nothing wrong with them apart from prematurely having a body temperature of 39 degrees Celsius (which is safe, by the way).  This is often over-interpreted and called heatstroke, when all they are is hot and tired too early in the race (race winners will be close to 40 degrees, by the finish line, and therefore "acceptably" hot and tired!)

But the point is, the pace must drop on a hot day.  These two articles explain the physics of heat loss and how pace has to be adjusted on a hot day:  

• Bodil Nielsen - Atlanta and a fight against physics
• Dennis & Noakes - advantage of small mass when running in the heat

That second example also shows how being smaller is an advantage during exercise in the heat, and this is one of the reasons that the elite runners are less affected by the hot conditions than those running 3h30.  They tend to be 60kg, tiny runners, whereas those at the back are often 50% heavier.  That, plus the adaptation to the heat as a result of where they train, means that the elite will problem be slowed by 2 to 3 minutes, whereas those at the back could lose 10 to 20 minutes on a hot day.

 

Bottom line - the body knows.  So listen!

The bottom line, however, is not to panic about the heat.  Yes, it makes things more challenging, and yes, the risk goes up.  But only if the runner ignores the obvious, disobeys common sense, and disobeys their own body, in two important aspects - hydration and pace.

So the only guidelines you need listen to are the following:

• Run within yourself, not to the clock; and
• Drink to thirst

Simple as that.  So by all means, if you're not able or willing to adjust the goal from a 2:59 to a 3:10, and if you've been training early in the morning in temperatures of 4 or 5 degrees, rather than 27 degrees, then this is a Boston race to miss.

What it is not, however, is a race that "could kill you", and the heat is not a death sentence that should be avoided at all costs.  And whatever you do, don't drink everything in sight!

Ross

Marathon season: Ethiopia surge back with Men's & Women's wins

Ethiopia's day as course records fall, but not to Kenyans

If 2011 was the year of the Kenyans, then 2012 is shaping up as the year of the rivalry.  Last year, Kenya exerted a total domination over the marathon scene, winning every Major city marathon, breaking every course record, claiming World Championship gold, the top 20 places on the world ranking lists, and the world record.

So far, 2012 has belonged to Ethiopia, and April 15th was without doubt their day.  Of the four individual titles on offer on the streets of Paris and Rotterdam, Ethiopia claimed three, along with two course records.  The lone exception was Kenya's Stanley Biwott who won the Men's Paris Marathon in 2:05:11, breaking the course record by 36 seconds.

But for the rest, it was all about the Ethiopians.  Biwott's achievement in Paris was matched on the women's side by Tirfi Beyene of Ethiopia, in a course record 2:21:39.

Then, in the much anticipated Rotterdam race, where Moses Mosop was talked up as being in with a good chance of breaking the World Record, he ended up third, beaten by Yemane Adhane and Getu Feleke in 2:04:47 and 2:04:49 respectively.  Another pre-race favourite, Peter Kirui, who showed his form by winning the New York Half Marathon recently, was never in the race, running with the second group of men almost from the start before dropping out at just before 35km.

So that's a really disappointing day for the big-name Kenyans, and Adhane's win snapped their 13-year win streak in Rotterdam.  It also somewhat burst the bubble of invincibility that had sprung up around Kenyan marathoners in the last 12 months.  

Women's race - fourth fastest performer ever for Ethiopia

And perhaps even more significantly, Ethiopia's women raised the stakes even higher with the performance of Tiki Gelana.  She raced her way to becoming the fourth fastest woman in history and running the seventh fastest time with her 2:18:57.  

It's amazing to think that in women's marathon running, we now have Shobhukova, Keitany, Kiplagat, Gelana, Mergia, Kabuu and Dibaba all with sub-2:20 performances since London last year.  And that list doesn't even include and Firehiwot Dado or Bezunesh Deba, who raced New York, not renowned for super fast times, or Bezunesh Bekele, who ran 2:20:30 in Dubai earlier this year.

But take a look at those names - Shobhukova stands out as the lone non-African, but of the other nine, six are Ethiopian and three are Kenyan (Keitany, Kiplagat & Kabuu), and so the pattern on the men's side is repeated for the women, and it should make for an incredible season in 2012, particularly in London in August, when these nations will go head to head.

Ethiopia's dominance reflected in the world lists...so far

The amazing statistic that emerges after the dust has settled on this, the first day of the 2012 Spring Marathon season, is that in 2011, seven men broke 2:05 (if we include that freakish day in Boston where 4 men did it.  Take it out, and there were only three men under 2:05).  So far in 2012, SIX men have done it, and we're only in mid-April and yet to see a Major Marathon.  And more remarkably, aided by Dubai and now Rotterdam, FIVE out of the six are Ethiopian!  

On the women's side, Ethiopia occupy five out of the top six places as well, led by Gelana's Rotterdam win.  Of course, the real big guns from Kenya are yet to race, both on the men's and women's side, and we should see those rankings change a little next week after London, which is an incredibly strong and deep race on both the men's and women's sides.  Boston is unlikely to challenge the lists because of predicted high temperatures, but London should, so the picture will be clearer then.

What is clear, after today, is that Ethiopia, and not just Kenya, have some selection problems prior to the Games, but more on this later...

The Rotterdam race: Splits and insight

In Rotterdam, windy conditions blew away the chances of a record, but it was the race that begs for more insight.  Moses Mosop was heavily touted before the race - our friends at Letsrun.com profiled Mosop as a marathoner who had "never seen before speed".  Mosop of course had run 2:03:06 on that windy Boston day, and followed this up with a world record over 30km and a record time in Chicago, so he's clearly one of the current best.

In the end, it was not his day.  He was gapped shortly after halfway, and while he fought hard and managed to reel the Ethiopians back, he could 'only' run 2:05:01.  The split table below, taken from our friend Andrew's split table, shows how they were under world record pace for a long time, but a very slow 10km section from 30km to 40km (30:14 for 10km) saw the record possibility disappear.  If anything, the early pace was just too fast - 10km in 29:05 projected a 2:02:43, and even at 20km, the projected time was 2:03:00.

To bite off 38 seconds from a strong record is a tough ask, and I'm sure that the wind will get most of the blame for the ultimate failure to break the record, but that early pace is too quick and would have cost at least some of the overall time lost.

It seems bizarre to say that a 2:05:01 is disappointing, but most people debating the London Olympics would have mentioned Mosop as a "must-run" name.  That now seems far less certain.  And if London next week produces fast times and Kenyan victories, then Mosop doesn't go to London, such is the level of competition for Kenyan places.

I would argue that Geoffrey Mutai, based on his Boston and New York wins, must be selected almost regardless of what happens in Boston tomorrow - to win two unpaced marathons the way he did suggests racing quality that can't be overlooked because of a potential bad day.  The remaining places are there to be contested between Emmanuel Mutai (if he defends his London title, he goes), Abel Kirui (a strong favourite because of his World Championship performances for Kenya), Patrick Makau (world record, enough said), Wilson Kipsang (probably needs a fast win in London) and perhaps Mosop.  Or any other exceptional Kenyan who emerges either in Boston or London next week!  But when framed this way, Mosop's 2:05:01 may have closed the door on his chances.

Ethiopian athletes, on the other hand, have blown the door wide open, and their team selection will be equally interesting.  When you have five of the top six to choose from, plus a handful of more experienced 'veterans' yet to race, you're in a difficult luxury position.

Bekele is also back - Dublin 10km win

And finally, other good news for Ethiopia is a return to racing for their great track athlete, Kenenisa Bekele, who won the Dublin Great Run over a hilly course in 27:49 (race report here).  That's a big bounce back from his very disappointing run in Edinburgh a few months back, and the manner of the victory suggests that he will arrive in London in good shape, assuming the upward trend continues and he avoids injury.  That's bad news for Mo Farah and all others in the 10,000m (and possibly the 5,000m, time will tell), but great news for Ethiopian athletics.

All in all, a great day for Ethiopia.  Boston is next, and the real big guns from Kenya, first with Geoffrey Mutai, who will attempt to address the balance!  Join us tomorrow!

Ross