The TTBikeFit BLOG:
We don’t post that often these days, but there is a ton of good archived info here and when we have something REALLY SMART to say, look no further!
Late-breaking race report here on Kona #7. 1996 was my first one after which I took a triple-baby pause and then raced it 6 years in a row. Every year I intend to take a Kona-break and this time I really mean it. After last year’s epic meltdown, however; ending up 4th AG after having lead for 136 miles, I wanted to come back and have a race I could feel good about regardless of placing (thanks Coach for subliminally putting that in my head). This meant taking an honest look at why I failed last year. And I say honest because I sure had come up with a lot of excuses for my disappointing race.
Last year’s big race was Norseman Xtreme, 10 weeks before Kona (race video here). I came into Norseman having trained in the 4th flattest state but with a lot of strength work to try to make up for the lack of steep terrain. I had a great race in Norseman and as result felt that if I can do well at Norseman from training on flats, I can do anything. Feeling invincible was my first mistake. So my Kona build lacked the ever important post ironman re-balancing of my strength and mobility. Yes, the core sessions were in there as always but I justified it to myself with time limitation related excuses. What I did I rushed through with bad form. My hip flexors are particularly tight if I don’t maintain the (boooring) work and my glutes are traditionally weak; those are my trouble-spots as I sit a lot at work. End result – I went into Kona with confidence that did not match my readiness. Couple that with an extraordinarily tough wind and heat year that had me dehydrated plus being too aggressive on the bike – I started going backwards during the marathon. It is never a good idea to set a time goal for Kona. Madam Pele scoffs at time goals.
Fast forward to this year, Kona was intimidating me once again. But Coach Al and Todd helped me get my race goals sorted – the focus would be on preparation, planning and executing those plans perfectly without regard to overall time or what my competitors were doing (at least until the 2nd half of the run anyway). So I made the trip to PAP (Pursuit Athletic Performance) to dial in the circuits I needed for my current strength and compensations and to make sure I was doing them right – it was humbling to have to revert back to the very basic and easiest versions or exercises. Like the half front planking with reach making sure the stick across your back does not move at all – such an easy concept but impossible to do right if you compensate. But yet – as my mother said when she saw me in action – every single person in her gym obviously does with wrong form when she realized how much I had to concentrate to get a tiny movement like that perfect.
We started the Kona build 10 weeks prior with an average of 15 training hours per week (the relatively low volume is due to time constraints but is offset with some mighty high intensity sessions) and a couple of 18 hour weeks. To minimize pool time I used the VASA increasingly – our local pool had been torn down and rebuilt so this had been my sole swim option all winter anyway. It’s amazing how well it translates to the real thing. When the Bay warmed up, most swim sessions were open water. I also started doing track with pure runners at Brown University – I can’t thank the Ronald McDonald House Running Club coaches and runners enough for the support and comradery. These sessions got me so far out of my comfort zone and I was humbled at how far these folks can fly with each step. I could tell it was beneficial to mingle with the fast.
Now to some bad luck along the way. A slight setback in June where I lost 1/5 of my blood with a visit to the ER; no surgery needed, just iron supplements to get me un-anemic again (freak female related stuff). Then one month before Kona I came down with Shingles (we call it ‘Hell’s Fire’ in Norway for good reasons, please let me never get this again). The nerves wrapped around my back were inflamed; a pain that is always on during the course of the illness. Ibuprofen around the clock. Careful swimming was possible. Biking was interesting – getting my leg over the top tube was a dilemma but once I was in position I could bike. I just couldn’t put my foot on the ground to support my body weight as it put too much pressure on my back when moving from a ‘floating’ position to a weight bearing one, therefore much of the biking was done indoors. The long rides were outdoors and Peter Russo who was also building for Kona would make sure intersections were clear while I was circling. Running for some reason felt fine, something I can’t explain. The whole affair was a pretty good reminder to keep good posture – once I moved wrong I got shooting pains. 10 days before the race I was pain free but a disaster movement-wise. Coach Al made a rush trip to RI to evaluate the damage and this was extremely critical as it turned out. Had he not redirected those last few strengthening/stability training sessions and helped me “turn on” and activate the stabilizers around my hips, I probably would not have had the same result.
Kona week – heat acclimating and getting the body straight were the focus; 3x per day I worked on my new strength circuit. Not the kind most people associate with ‘panic training’. Staying off the feet as much as possible during pre week is always tough but I did a good job this year. 3 days out I felt really good but then had a bout of bad luck again during our daily swim back from the Kona Coffee Boat. The person in front of me decided to dive down, he kicked straight up and hit my head with a hard blow. I saw some cartoon style gray stars and everything became quiet it seemed for a second. For the 3rd time this year I thought there goes my race. It was a violent kick and what’s weird is the person never checked on me. I hope his foot hurts a lot because in writing moment a month later the bone by my eye still aches and it hurts to roll my eyes.
Enough of the soap opera drama, race day was a perfect day. Celebrity racer Chef Gordon Ramsay of Hell’s Kitchen walked by me during early morning transition and whispered “you have a good race, OK?” Sir, yes Sir – having watched his show and seen the consequence of a bad pie I knew a good race was a must. There was no swell during the swim and optimal conditions. I lined up in the middle of it all and must admit I was concerned about contact to my head. I felt vulnerable. I tried to avoid the flailing arms and legs and was pleased when I got to the turnaround boat with minimal roughness. Because of the lack of swell, I was able to sight the buoys and swim straight. My biggest wish for this particular race is more frequent and taller buoys – if there is a swell you often can’t see the next buoy. I took my time in T1 to actually sit down, get my heart rate down and drink a lot of water which was served to me by my fabulous team of 3 ladies. I could have spent all day in there being pampered. Swim 1:03.
The bike was hot as usual but fast. We had no winds up to Hawi nor cross winds coming down – a fabulous treat it was! We had a nasty headwind on our way back along the Queen K for a couple of hours, maybe less. At the feedbag hand-off in Hawi I had another ‘there goes my race’ drama. Somehow my special needs bag hit my aerobars and I flew over my handlebars. Good grief. What’s amazing is all the things I had time to think about during the actual flight before I hit the ground. I went through several emotions from fright to disappointment to shit happens acceptance. I rolled shoulder first and the bike landed on me. The volunteers swiftly got me up and on my way after checking that the helmet was intact. Some time later a girl in my age group, Diana H passed me going very strong – I picked it up trying to keep her in my sight but the pace was too fast and my master plan was to be more conservative than ever – I could see she was working very hard and thought (hoped) maybe she would come back later. I didn’t know who else might be in front of us. Bike 5:15.
Run – my plan was to be overly conservative first half and then go. We had a nice cloud cover early on which was another fabulous treat. It made a big difference. Still it was hot but instead of 107F it was 87F. It was a very humid day, the dew point was 72F. Overall it was a much easier year than last. At the 5 mile turnaround I was surprised to see Diana H only about 1 1/2 minutes ahead. I passed her up the road and we established that there were no one else in our age group ahead. I told her to stay strong (but not too strong). I figured the next girl in our age group was 11 minutes back, but holy cow she looked good! She was running fast and I tried not to panic. She told me the next day she is a 2:52 open marathoner… I kept my pace comfortable because I felt with all the happenings I didn’t have a big margin of error if I wanted to stay strong and steady. I was gun shy from previous years and I started doubting myself. Up the long steep hill at mile 10 to the Queen K and this is where I walked for the first time – through the whole length of the aid station to make sure I was completely caught up on hydration. My stomach felt good. I saw Todd and Peter (who ended up with a torn hamstring right before Kona and was spectating) and they yelled that I looked good. At this point – half way – the plan was to pick it up and just go for it. My fitness should have been up to the task but I was still afraid to blow up like so many times before so I kept it comfortable. Into the Energy Lab and down to the 17.8 mile turn around where you again can start looking where the competition is. About 45 seconds later here comes the German girl who was 11 minutes back at mile 5 – crap!
We had 8 miles to go and this is where I actually said to myself – 2nd is good! I grabbed my special needs bag which contained a couple of Glucose Shot bottles which I had picked up in the diabetic section at Wal-Mart. This was something new I had tried in training as my stomach always gives me issues late in the marathon. Glucose doesn’t require the stomach to do any work as it goes straight into your blood stream – and so it did! I told myself – yes I was talking out loud at this point – that if she is to pass me I am going to make her work for it. In order to feel good about 2nd place I had to work as hard as I could in order to truthfully say I did all that I could. I picked up my cadence and ran my best up the one mile hill and out of the Energy Lab. I took small sips of the Glucose and started throwing down coke and water at aid stations, wow I felt good and happy. I concentrated on my form and tried to stay tall. This is typically the point where people are losing it big time but we had planned my whole race around feeling good here and being able to let it rip. I saw Todd and Peter again at mile 22 and wondered where they had been – I didn’t realize they had closed the road at mile 13 for spectators this year, which was mile 22 going back. Hopefully they will change this back. It was too lonely. They yelled that I was looking good but I yelled back,”she is coming she is coming”! I pressed on. A little later Diana H’s husband appeared (I know as he introduced himself) and told me I was killing it – I was not able to respond at the moment but realized later that this person was a class act, motivating me in a time of battle. Todd and Peter appeared while I was running up the last one mile hill and informed me I was now 4-5 minutes ahead! What? HUGE relief – the strategy to be patient was working. I could relax and enjoy the feeling. I was proud that I had finally executed in a way that allowed me to feel strong in the last miles. This had never happened before. The high fives from kids were flying down the finisher chute; the happiest of endings (alongside Norseman of course). Run 3:37 Total 10:03:26
Lessons learned: Madame Pele requires respect. Trust your coach. Don’t take your past performance for granted. It’s the little things that may end up making the biggest difference. Big thanks to my long-time loyal support: Todd of course and Coach Al, FuelBelt, Pursuit Athletic Performance, Steven Harad (bike sponsor), PowerBar, Speedfil, VASA, and ISM. And last but not least to this crowd at home – my mom who flew in from Norway with the troll trio.
This is the last of our Kona cycling videos for 2013. That is other than some bike fit analysis coming soon. And we also have run footage. I actually have a backlog of great run footage, including the Boston Marathon and Eagleman 70.3. So lots more vids to come…
This video shows the first 14 age group men into T2 at mile 110 on the Queen K. It also shows some other top finishers that came by a bit later. The time into T2 among the riders in this video ranges from 5:38:04 to 5:46:09, for a range of only 8 minutes. Finishing times were much more widely distributed…
Many of the top age group finishers are in this video, including top overall age grouper Kyle Buckingham, and fastest biker Sam Gyde, along with 2011 overall age group winner Sami Inkinen. Many of these athletes out-rode many of the pros, and some ran sub 3 hours too. Several went well under 9 hours. It is interesting that the age group times were notably faster this year while those of the pros generally weren’t. Yes, the age groupers have a smaller draft zone than the pros, but have more heat and wind due to the later start time (although this year this was likely less of a factor than usual). All of these riders at the front here were draft legal when they passed me, even though the first four were in a loose group as were some of the riders near the end of the video. However, a bit later some huge packs came by.
The bike fits of most of these riders look quite good. There are a couple that could potentially be improved, but the positions are generally excellent. So whereas the choice of equipment varies a great deal across this bunch, the fits don’t.
Note that the first 4 riders were not filmed in super slo-mo due to a technical glitch, but I have slowed the video to approximate the effect. Also note that I do not film the top age group women, because by the time they pass by, the Queen K is packed with male age groupers and it is very tough to spot the women among them and capture them on video.
Now we move to the women’s pro field, with this video of the first 17 pro women into T2, shot at 300 fps. After six consecutive years of filming on the Queen K, I can say that in general the women’s positions have become more aggressive and more similar to the men’s. In this video you will see both ends of the aggressiveness spectrum and as always some questionable fits. More on this soon when we release our Kona fit analysis videos. We also have a video on the way showcasing the fastest male age groupers.
Part 2 of our video study of the male pros passing thru mile 110 on the Queen K. As always, slo-mo shot at 300 fps. Some of the big names are here in this group of the 13-26th pros into T2. These include Tim O’Donnell, Crowie, and Pete Jacobs. Whereas the faster bikers were pretty well strung out, here we see a group of several athletes (trailing TJ Tollakson at this mile marker) who all rode around 4:40. Although riding in a group, they certainly look legal as they pass. We also see the two fastest runners of the day, Ivan Rana (2:47) and Bart Aernouts (2:44) who both ran into the top ten while many others in this video went backwards.
I continue to hear that the draft zone was in fact extended this year (again) for the pros. But I am not still not sure if this is the case, even though it might explain some of the race outcome. What’s confusing matters is that the draft zone has already been larger than regulation in Kona for the last several years, but this has effectively been a “secret” (see this article by Aaron Hersh). The lane reflectors on the Queen K are about 12 meters apart. For the last 3-4 years at least, the “secret” pro draft zone in Kona has been set by the reflectors, effectively extending the standard pro draft zone (10m front wheel to front wheel) by 3.5m (assuming back wheel to front wheel spacing set by reflectors = 12m + 1.5m for bike length). Or has it actually been front wheel to front wheel on the reflectors = 12m draft zone? Not according to that article… So was it really extended further this year? Anyone know for certain?
This video also shows some questionable bike positions – more on this in a later video. Until then, have fun:
Here we go again – the first of our 300 fps super slo-mo videos from Kona. Well the 2nd really – we put an early edit up on Xtri.com while still in Kona, but now that we are back at TTBikeFit HQ we will be churning out several more. This one features the first 12 pro men into T2 approaching the finish of the bike.
The conditions were certainly easier on the athletes this year than last year, not to mention much easier on us. Everything is relative of course – Kona is always hard. This year though the raging winds typically felt in the last 7 miles up to Hawi were largely absent, even for the age groupers. In some years these winds don’t show up until after the pros have come and gone. Age groupers did report strong headwinds from Waikoloa to the airport (approx mile 85-105). Not sure whether the pros experienced this as well but I am guessing they did. The heat was also not as bad as it often is – haze and then cloud cover kept things relatively hospitable.
That all said, we still saw quite a few blowups among the pros, and some slow marathons. Mark Allen is on record as saying that no one runs as fast as he and Dave Scott did because they bike so hard nowadays. Chris Legh mentioned to me before the race that the draft zone had been increased by two meters this year, and that he had found it to be enough to remove any drafting effect during training rides on the Queen K. It looks as if he was right as the mens’ pack blew apart on the way back with huge gaps between the first several riders. In past years you often had one bike specialist off the front, and then a few big groups of chasers. This could also explain the relatively slow marathons in the cooler than usual conditions. Uber-bikers Starykowicz, McKenzie and Kienle let it rip, and the run specialists had to make a decision as to how much time they could afford to give up versus pushing the limit on the bike. The decision was tougher this year as they apparently couldn’t depend on pack riding to help them stay in contention. Van Lierde seemed to find the sweet spot, as he ceded a bit of time on the bike to the front riders while staying well ahead of the run speedsters into T2. He was then able to pull off a decent, if not great marathon for the win.
There will be several more bike and run videos coming, including some with bike fit analysis. Until then, enjoy the first chapter:
As always I stood on the searing pavement in front of the King K to bring you pics of as many pro bikes as possible. Enjoy!
Defending Ironman World Champ Pete Jacobs unveiled his new machine at the Kona expo yesterday. Boardman Bikes founder, Olympic gold medalist, hour record holder, and yellow jersey wearer Chris Boardman was on hand to explain some of the development that went into the bike. See the video of the unveiling below where both Chris and Pete talk about the design philosophy and features of the AiR/TTE/9.8.
Clearly the artfully curved and blended front end of the bike catch the eye. As is the current trend, cables are hidden. The bike looks exceptionally clean, almost minimalistic. The integrated bars/stem blend beautifully with the head and top tube, and a removable hatch provides access to cabling and the Di2 junction box, as well as a large opening in the frame. The frame is compatible with both mechanical and electrical shifting. The front brake cable descends through the steerer to the brake encased in the massive fork (there are removable covers on the sides of the fork for brake access). Apparently Chris has tested the fork and brake in the alps to make sure that it is up to his standards for braking and control under extreme conditions. The integrated aerobars will provide a range of pad stack, reach, width and angle adjustments. The pads on the show bike were just prototype pieces – seeing as the bike had just arrived from the factory hours before the unveiling, there are still a few details to be ironed out for production.
The rear end of the bike continues the clean, no-frills theme. The seatpost binder is a standard collar clamp, but it is buried inside the frame. Pieces of tape covered the binder bolt access holes on the prototype. At first glance, it looks as if there is no seatpost binder mechanism at all. The rear brakes are the now common TRP mounted beneath the stout chain stays. The seatpost has a 4-position clamp. The frame is built on a 78 degree angle, but the forward clamp position gets the effective seat angle to 80 degrees. Interestingly, Chris mentioned to me that he believes the trend will be to even steeper seat angles over the coming years. Back in the day Chris was known for riding the Lotus Superbike at ridiculous speeds both on the track and the road. Although that bike was built around typical slack road bike frame angles, Chris sat on the last few cms of the saddle nose, at a very steep effective seat angle.
One of the main themes of the Air/TTE/9.8’s design was drag reduction at wide wind yaw angles. The Boardman design crew believe that real world athletes experience on average broader yaw angles than most bikes are optimized for. So their new design was aimed at performance at 20 degrees yaw. There is no doubt that Kona athletes experience very high yaw on the queen K.
I had the opportunity to speak with Chris about his hour record days. He said that the Lotus bike was worth about a second per kilometer over anything else they tried. And the non-protective thin shelled aero helmets also created a great aero advantage versus today’s certified helmets. But the biggest gains he achieved were via the superman position. He recalled that the first time he tried it on the track, he rode three laps and then looked at his average power and speed, and was shocked at the gains over his standard TT position. He said he then knew he had to ride that position. And amazingly, he said it was quite comfortable and efficient despite appearances. No word on whether the next Boardman Bikes TT model will offer an optional “Superman” front end…
I had the opportunity to spend some time with Chris Legh at the Fuel Belt house on Alii Drive. Chris is returning to the big show this year after a multi-year hiatus, and he seems super relaxed for someone who has had his share of challenges when competing at the Iron-distance. For a great summary of Chris’s career, click
Trek shipped out a custom 2014 Speed Concept just a few weeks ago, but Chris tells me he really likes the bike and feels very dialed in. You can see that he is using a high hand position which he says lets him drop his head right down on his hands, which should be good for aerodynamics. There is no doubt that the new Speed Concept looks super clean. You almost get the impression that is a track bike as there are no cables to be seen anywhere. The integrated storage boxes add to the clean look. Chris chooses to ride with mechanical Dura-Ace, as he says he just doesn’t want to deal with the possibility of an electronic issue when traveling.
Chris plans to use one of the new generation of ventilated yet aero road helmets for the race: the Louis Garneau Course. LG says the Course is more aero than the Giro Attack 2, and it is clearly well ventilated. Lis and I
have been training with the Course, and she also plans to race with it. The Course has angled vents that allow air to flow through the helmet, above the rider’s head, when the head is held in a face-down position. When you ride behind someone wearing the Course you can see clear through the helmet from front to back. So this combined with the lack of a tail provide reduced frontal area and drag.
Best of luck to Chris on Saturday, and stay tuned for more updates from Kona.
I have had lots of response to part one of this discussion – please read and view it first if you haven’t already. The point here is to challenge some of the “common wisdom” out there about how you “should” run. And by “you”, I mean everyday runners and long course triathletes. If you are an elite runner, track athlete, or even a fast short course triathlete, I wouldn’t bother watching the videos. But, if you are everyone else, you may find something valuable here. In part one I laid out the differences in the two running styles, and touched on the physics involved. Bottom line, if you are running slower than 6min pace (and you probably are running much slower most of the time), should you emulate the running style of athletes running well under 5 min pace? Do you “need” to fly? Do you need the extra impact and potential greater likelihood for injury of the bounding Gazelle style?
If you are a speedster, yes. Physics demands it. Otherwise, sticking to the ground and turning over quicker may be the ticket. I think everyone naturally runs Gazelle style as a child – you are running in short fast bursts in play and sports. But what about sustained slower running – a very unnatural thing for children and most humans unless you take up endurance sports – or maybe unless you were a prehistoric hunter who killed much faster prey simply by outlasting it.
So why not try gliding if you aren’t running that way already? Yes, you can consciously change your running style. I did and essentially overnight I was running 20 secs+ per mile faster for longer distances. For me, paces around 1/2 marathon race pace were easier to maintain – they felt much more sustainable. And that could be a big plus for long course triathlon where most folks slow way down as the run progresses. Plus, I was less beat up after long tempo runs. In fact I wasn’t beat up at all, other than feeling it some in my hips and butt – hips from testing my mobility, and butt from drive off of the back foot. But no impact soreness.
And that brings up the fact that to be a GOOD glider, you still need the posterior chain to activate and drive your forward, and you need hip mobility. You need good rearward extension, which requires supple hip flexors (not a common characteristic of triathletes who spend hours in the aero position) and t-spine mobility. But you may well not need nearly as much “spring” as Gazelles do. And that is good news for everyday runners and especially “older” athletes. So a good foundation still matters, and the better it is the better you will run regardless of style.
Other than analyzing videos of yourself running, how can you wrap your brain around gliding? Two visualizations I have used are Nordic skiing and skating. Get that front foot swinging down from the knee early to help propel you forward. In both Nordic and skating, the motion of driving the front foot forward helps propel you off the back leg and opens the stride.
What DOESN’T matter? Foot strike for one. I can see from the comments under the first video that folks are obsessed with “strike”. I’ll say it again – just don’t BRAKE. Land midfoot, forefoot, or even touch your heel lightly – just don’t stop yourself on each stride. What many think is a heel strike is really just a heel touch on the way to a mid-foot landing. If you achieve weighting mostly under your center of gravity, then it really isn’t going to matter how your foot touches the ground. The foot needs to be “pawing back” as it touches and not weighted until it’s under your hips. True heel striking involves crashing your heel into the ground well out in front of your hips – sending most of the shock from the landing straight up your leg into your hips and back. Please don’t do this. It hurts just writing about it.
So check out my “part 2” video. I look at some more pros, but also look at an everyday runner – me – running both ways at different paces. I also talk about the types of athletes that may benefit most from each style. And just to be clear, I am not trying to be dogmatic here. I am not saying that changing styles is a magic bullet or this is the “only” way. You will still need to work on range of motion and mobility. But maybe gliding will let you take greater advantage of what you have to work with.
What follows is a brain dump in condensed form – a run technique manifesto derived from what is now years of studying high speed videos of the best runners on the planet. There is plenty of advice out there these days as to how you “should” run. How your foot “should” land. What your arms “should” do. How much you “should” bounce. What your cadence “should” be. My conclusion is that you “should” ignore most of this advice. I have identified two distinct running styles exhibited by Ironman’s best runners. They are dramatically different as the video above illustrates. One group, the “Gazelles”, spend half of each stride airborne, gaining altitude after toe-off in a clear projectile-motion path. The other group, the “Gliders”, spend about half as much time in the air, and more or less fall off their back foot onto their front foot while exhibiting notably higher turnover. Very different styles, yet we have practitioners of each throwing up 2:52 Kona marathons on the women’s side. Gazelle Carfrae vs Gliders Wellington and Snow.
So I am not going to tell you how YOU “should” run. But I am going to try and point out why one style MAY be better for average age group runners, and perhaps most women, even pros. Physics drives my arguments and observations. Even fast runners cannot escape the simple laws of physics. So too, if you want to run your best, whichever style you adopt, you must be strong, stable and mobile. Period. There is no silver bullet that will make you a fast runner if you lack the foundation. You must be able to extend your hip, and you must be stable and strong enough to avoid leaking energy.
The basic differences between Glider and Gazelle technique can be seen in the video. But to summarize, both runners exhibit similar back leg extension at the moment of toe-off. However, the front leg position is different. Gazelles are less open with the lead foot under center of mass and exhibit more forward lean, whereas Gliders are fully open at the hip (front knee at maximum displacement) and the front foot has already swung well out in front of the center of mass. In fact this swing likely generates some of the forward velocity. We think of this as being similar to skating. While the Gazelle gains a bit more altitude after toe-off, likely aided by additional upward knee drive, the Glider mostly falls onto the front foot. So flight time is short. The Gazelle is still flying around up there while the glider is working towards their next toe-off.
Classic run form, the one you see world-class marathoners use – all of them – is gazelle-like. By that I mean the runner exhibits a relatively large amount of vertical oscillation – 4-6″ typically, during which time the athlete flies through the air. (YES “bouncing” is necessary if you want to run like a gazelle – physics won’t let you move at elite speeds without significant flight). We will now introduce a KEY physics concept: vertical and horizontal motion are INDEPENDENT of each other. The amount of TIME a runner spends airborne is solely a function of how much vertical force (and hence velocity, Vy) he has on toe-off. It does not matter how fast a runner is moving in the horizontal plane (Vx). The runner is governed by the laws of projectile motion. If you hop straight up, the velocity you leave the ground at determines how high you will jump, and how long you will be in the air. Same thing for a runner. So Gazelle runners use some amount of vertical force and the resulting Vy to gain altitude after toe-off, and hence remain in the air longer. Now, the faster a runner is going, the more ground he will cover while in the air. And this is key, because we find that in fact Gazelle runners typically use a cadence very close to 90. So to go faster at a steady 90 cadence, you must go further with each step – increase your stride length by flying through the air, because there is only so far you can open your legs. Flying is good in that while you are soaring, there is effectively no energy cost. But there is certainly an energy cost to generate that Vy which launches you up there, and to absorb it on landing.
Race walking serves as the opposite condition. Race walkers are not allowed to fly at all – even though they do for about .02-.04 seconds. The rule is just that it must not be perceptible to the judge’s eye, and .04 seconds of flight seems to be the maximum safe amount. In comparison, we find the typical Gazelle runner spends .17 seconds airborne. Elite race walkers exhibit stride lengths of around 4 feet, and cadence of 100-105. This limits their top end speed to about a 6:25 mile pace. Now to get this stride length they use hyper-extended knees and unusual-looking hip gyrations. But effectively no flying, no Vy. And under these conditions, their speed is limited by the humanly-possible stride length and turnover rate.
Elite marathoners travel at faster than 5 min/mile paces, yet our (and many others’) observations find that they tend to use a 90 cadence. The table below shows that each stride must be 6 or more feet in length. We have already seen that race walkers top out around 4′ per stride (no flying), indicating that the marathoners must fly at least 2′ per stride. likely more. Interestingly, we find that during the typical .17s flight, a marathoner moving at sub-5 pace would fly almost 3′.
What about the Gliders? We find they are only airborne about .1 seconds. Why? No Vy. Gliders achieve maximum vertical displacement at toe off, and then effectively fall onto their front foot. As opposed to a projectile, their travel through space is more like an object that is slid off of a 3″ high table (the vertical displacement at toe-off) at whatever Vx they are traveling at. So without the altitude gain, they spend less time in the air, and hence cover less ground. But they can and do turn over faster. We find that support times for both groups of runners is very similar. It is only the difference in flight time that makes for a shorter stride duration and hence quicker turnovers. While elite marathoners run at 90 cadence, we find Ironman Gazelles often run closer to mid 80s. But Ironman gliders are typically mid 90s cadence or higher (pushing 110 in Cait Snow’s case). When you watch the video above, it is striking how close to the ground the gliders stay – how little flying they are doing. Yet they go as fast as the gazelles, at least in Ironman.
So the question is, is one style more efficient? The gliders don’t use any energy to generate a Vy. All of their energy goes to Vx – moving forward. Note that they often look as if they are skating just above the ground with no bouncing. BUT – they do need a faster turnover. The Gazelles must generate a Vy, and in turn absorb the same Vy on landing. Clearly more costly energy-wise – BUT – is active muscle contraction used, or is most of the force generated through muscle and connective tissue elasticity? If so, the additional energy cost may be greatly reduced. But if you don’t have springs for legs, trying to run like a gazelle is probably going to be very costly – especially if you aren’t one of wraith-like physique. Both run styles need Vx obviously – Newton (physicist, not the shoe) told us long ago that once an object is in motion, it tends to stay in motion. So a runner’s forward velocity should be fairly easy to maintain, if you aren’t braking on every stride. And here is my one sentence on foot strike – land however you like – just don’t brake. Unfortunately for Vx, we aren’t running in a vacuum (although it may feel that way to your lungs at the end of a race), so there is some energy required to overcome aerodynamic drag. Of course this is the same for both run styles assuming the same run pace.
Clearly, at some pace, it becomes impossible to be a glider. The stride length or turnover needed becomes too great. We think this is around 6min/mile. Much like race walkers top out at around 6:25, gliders with their shorter flight time and hence shorter stride length succumb to cadence limits at some pace. But for most of us, especially in Ironmans, running a 7 min mile would be huge. The table shows that at a 90-95 cadence, you need about 4′ per stride. If you can open your legs to a 3′ stride width, then you need to fly a foot – very doable using the gliding technique. Yes you need the hip extension and glut drive to maintain the forward velocity. But you don’t need to fly much. Maybe, just maybe, this is the way most of us should approach long-course running. Heck, and 8min/mile pace is pretty darn good. In which case you can run at 90 cadence and travel 3.67 feet per stride.
Clearly there is room for further study here, and I can think of several possible scientific studies on this topic. Why do we see few men using the Glider style? Pace limitations? Don’t know. We plan to keep working on this topic and conducting evil experiments on ourselves and any other hapless subjects we can find. How “should” YOU run? Maybe not like a resident of the African plains (human or animal). Maybe gliding is the ticket to faster more efficient running, at least if you are a long-course triathlete.