Alan Couzens, MS (Sports Science)

"Devoted to the science of Maximal Athletic Development"

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The Benefits of a Legal Draft in a Windy Race

Alan Couzens, MS (Sports Science)

Oct 13th, 2014

With another Ironman World Championship in the books, it’s time for that all important post-race reflection.

This year’s edition of the race saw a return to the normal tough conditions that Kona is known for, i.e. heat and WIND.

The latter of these was particularly strong this year and, consequently, played a major part in the race.

In somewhat atypical fashion, winds were very strong very early in the bike, especially for the age-group male pack and were almost a direct headwind at this point. Later in the race, while remaining relatively strong, they shifted easterly into the sketchy crosswinds that the Kona bike is well known for. Click here to read more....

What type of athlete are you? Part 2:Your Brain

Alan Couzens, MS (Sports Science)

Oct 2nd, 2014

"It is exercise alone that supports the spirits, and keeps the mind in vigor." ~Marcus Tullius Cicero

In a previous EC article, I looked at some of the physical differences that I see, as a coach, between athletes that impacts how I program for them. I broke this classification down into 3 broad categories – high responders (‘The Naturals’), average responders (‘The Realists’) and low responders (‘The Workers’). I’ve recently been reading a great book called ‘Squat Everyday’ by Matt Perryman. In it, he comes to a similar conclusion about the responder-non responder spectrum (in the world of strength training) but also adds a new term to the mix – reactivity.

The idea behind reactivity is that we are all born with slightly different (mental) ‘wiring’ that affects how we respond to a given (general) stimulus. In one corner, we have the ‘high reactives’ – folks who perceive any given stimulus as more intense than average. At the extreme end, we might find disorders such as Autism, where stimuli is perceived as painfully intense. A little further along the scale, we might find the introverts, like myself, who find high stimuli environments very taxing from an energy perspective. Folks who need frequent periods of quiet and solitude to recharge. Click here to read more

Nutritional Periodization for the Serious Ironman…

Alan Couzens, MS (Sports Science)

Sept 18th, 2014

"Don't get set into one form, adapt it and build your own, and let it grow, be like water" - Bruce Lee

In a recent post I outlined the importance of a balanced energy system development for the endurance athlete with respect to aerobic glycolysis and lipolysis and the role that a balanced nutritional approach plays. I suggested that the athlete’s diet should match the demands of their training and that if they are training at intensities requiring aerobic glycolysis, by necessity, they need glycogen to power the training!

I really can't overstate the importance of getting this balance right and the importance of nutrition to the Ironman athlete. As I said in the last post, Ironman is fundamentally a game of a bunch of (similarly) very aerobically fit athletes testing their metabolic fitness head to head....Click here to read more.

How often should I breathe when swimming?…

Alan Couzens, MS (Sports Science)

Sept 12th, 2014

As often as you need to!
... end of blog :-)

Well, that short, simple answer is 100% spot on but I know you want more info that that. So here goes….

I saw this great article on on the subject of breath frequency while swimming & figured I would add some quick observations on the topic.

If you ask around the elite triathlete ranks, you might be surprised by the intensity of views on this subject. Some will swear by the stroke balance that breathing every 3rd stroke provides while others (typically ex pool swimmers) will sing the praises of the extra O2 that breathing every stroke offers. So who is right?

There is good reason for the intensity of positions on the subject – this O2 thing is pretty important! In short, it’s so important that other stroke considerations will be built around ensuring its adequate supply. So how much do we need? (click here to read more)


Fat Burning for the Serious Ironman…

Alan Couzens, MS (Sports Science)

Sept 9th, 2014

I received a bit of interest on yesterday’s tweet on the topic of Ironman metabolism shown to the left.

Most inquiries were asking what that 'ergogen..thingy' means :-) but a few of you were interested on where that balance point of the 'right amount' of fat burning for the serious Ironman athlete lies. So I figured I'd expand on that tweet and delve into the hot topic of LCHF (low carb, high fat) diets for Ironman athletes... Click here to read more....


Forget the disc wheel: Your most important 'upgrade' is the right crank!

Alan Couzens, MS (Sports Science)

Sept 3rd, 2014

I recently wrote a couple of articles on how bike geometry interacts with body geometry – specifically how your open hip angle impacts the stack and reach of your optimal bike frame. The one big factor that I left out of that equation that can have a VERY large impact on both comfort and efficiency is crank length.

Crank length is a sort of 'linch pin' in bike fit. An often ignored factor where fairly small errors can have quite large effects & an otherwise good fit can turn into a very bad one, especially if you happen to be unfortunate enough to require a smaller frame size (which will almost certainly come with a comically disproportionate crank length!).

A crank length that is too long for the athlete’s hip mobility will result in a number of compensations that, at worst lead to injury, and at best lead to high levels of discomfort during longer rides. Click here to read more....


Differences in the blood lactate curve: Ironman vs ITU

Alan Couzens, MS (Sports Science)

August 27, 2014

In a previous post, I outlined the way that I look at blood lactate data for the purposes of both setting the athlete’s training zones and identifying weaknesses in the athlete’s profile.

A great follow up question was recently raised and so I thought I would add some thoughts here. The question was “How does this analysis of strengths and weaknesses differ for short vs long course athletes?”

Below you’ll find 2 lactate curves – 1 from an elite long course (Ironman) athlete and another from a short course (ITU) athlete. Both are similar weight (low 70kg’s) and both equally accomplished over their respective distances. I would consider these curves and this data fairly typical of the differences that I see between these 2 types of athletes across the board.

Key differences.

  1. AeT (first inflection point) occurs significantly further along the curve for the Ironman athlete (70% vs 50% of peak power output). This is obviously an important training objective for the Ironman athlete and a key differentiator in training protocol.

  2. When the Ironman athlete’s curve ‘kicks’, it kicks hard! i.e. when the curve begins to turn up, it does so with a steep gradient, as opposed to the ITU athlete’s curve which is more gradual in its rise. This leads to AeT/LT/OBLA to be clustered close together Again, indicative of where the athlete distributes their training load & the relative importance (or lack thereof) of training significantly above the AeT.

  3. The ‘threshold’ point (via the modified D-Max method) is higher in the short course athlete than it is in the long course athlete. Again, clearly this point on the curve is more important to the shorter distance. An important observation: The reason that it’s further along the curve is because of the shallower gradient of all the points immediately above it. This has key training implications for short course events.

  4. The maximal numbers (both lactate and peak power output) are lower for the Ironman athlete. More than the SC guy being particularly ‘strong’ here, big volume Ironman training has a tendency to bring down maximal lactate & power numbers. I have observed a relationship between low lactate numbers and a poorer training response. Therefore, preserving some ‘top end’ even in the midst of Ironman training is, for me, an important priority.

  5. The exponent curves show that the % increase in power for a given jump in lactate is significantly greater for the short v long (~19% vs 13%) showing greater glycolytic power (and diminished lipolytic capacity) for the SC guy. Again, an important metabolic differentiator between short and long.

  6. Hopefully you will find the above data useful in monitoring your own strengths and weaknesses over the season and tailoring your training to the specific demands of your event.

    Train Smart,




    Diagnosing & Treating Your Swim Limiter: Part 1

    Alan Couzens, MS (Sports Science)

    August 18, 2014

    The guy above, Alexander Popov, represents my personal ideal of the 'textbook' freestyle stroke. I was very fortunate to spend some time during my studies apprenticing under his coach, Gennadi Touretski, who was, at the time, also the head coach of the Australian swim program at the Australian Institute of Sport. Not to put too fine a point on it, but Gennadi was a pure genius in all aspects of swim coaching – technique, physiology, you name it. However, if there was one area that he was known for, it was the emphasis on perfect technique for every single stroke swum during a session. Click here to read more


    Diagnosing & Treating Your Swim Limiter: Part 2

    Alan Couzens, MS (Sports Science)

    August 25, 2014

    In my last post, I gave an introduction to the 3 key technical swim limiters that I see among triathletes. Namely, Rhythm, Range and Relaxation. I suggested that, if you are serious about improving your swim this season, that it is essential to identify which of these are holding you back. Finally, I pointed your over to Swim Smooth for a simple but powerful 'diagnostic' tool to begin to identify your current limiter.

    In this article, I'm going to delve a little more into the practicalities of how to go about diagnosing your own swim limiter. I'll introduce you to a simple test that you can use to not only help to identify your own weaknesses but also to help you track improvement in these areas over time. Click here to read more.


    The hidden cost of an overly aggressive bike position

    Alan Couzens, MS (Sports Science)

    Aug 7, 2014

    With the 2015 bikes hitting the market, many Ironfolk will be ‘looking to upgrade’. Usually this means better materials, sleeker lines, hiding more ‘stuff’ &, above all else, more aggressive geometry. After all, nothing looks better rolling through transition than a bike with full aero set up and a huge drop. Big drop = low frontal area = this dude is serious about laying down a fast bike split!

    Well, there is one element of that equation that is missing – big drop + holding the position for 5ish hours = fast bike split!

    While a big drop may look cool coming out of T1, it looks a whole lot less cool when the athlete is sitting up riding the bull horns for the second half of the race. Not only does it look a little ridiculous, it’s also slow. How slow? Click here to read more.


    Know your enemy: Ironman Boulder

    Alan Couzens, MS (Sports Science)

    July 17, 2014

    “If you know the enemy and know yourself, you need not fear the result of a hundred battles”
    - Sun Tzu

    We (Endurance Corner) recently hosted a race prep camp for the coming inaugural Ironman Boulder. With the race course fresh in my mind (and legs), I figured now would be a good time to put together a quick synopsis of what athletes should expect & how they should strategically play the race.

    The swim is a simple 1 loop counterclockwise ‘triangle’ course in the waters of the Boulder reservoir. The only real significant feature of the swim is the bright sun that will hit you when swimming in the initial North East leg of the swim. This could make the initial turn buoy a little hard to spot so try to identify a larger landmark to the North at the start of the swim. It could also make sighting to the left a little challenging on the way back so be sure to have another good landmark at the swim finish. Tinted goggles are a must. Also, buoys will be on your left so get comfortable with some left side breathing.

    The bike course can be basically broken up into 3 sections as shown on the elevation chart below.

    Grades of 2% or greater are highlighted so that you can see how they are distributed across the course. As you can see, the most sustained uphill sections occur deep into the 180K. In terms of optimally pacing your race, a simple rule of thumb is to go ‘1 zone up’ on grades of 2% or more, ‘2 zones up’ on grades of 5% or more and the opposite of this for the downhills, i.e. on a 2% downhill, due to the higher air speed, athletes are best served in a speed:energy output perspective going easier than their average output. While, on grades of 2% or more, when air speeds are lower, athletes should be pushing one zone up from their average watts. For the Boulder course, with the most sustained grades occurring late, this makes a 'negative power split' strategy especially optimal!

    Section 1: “Steady comfort” (Transition to the end of highway 36).
    This is a rolling net uphill, with the longest stretch of consistent gain in the whole race. That said, grades, particularly in the early stages are not obvious. In other words, it is one of those phases where speed is slow & the athlete has something to push against. This coupled with early race adrenaline will lead many athletes to open up with an overly aggressive strategy. While I am generally a fan of “going fast when the race is slow”, if there is an exception to this rule, it is at the very beginning of the race, when heart rates are typically still high from the swim/T1 and the athlete is looking to settle things down in order to get ahead on nutrition. With this in mind, I consider this phase of the race a ‘steady’ (Zone 2) ‘get comfortable’ period. There is one additional nasty grade (not shown) in this section that has athletes rolling down and back up St. Vrain as a short distance tack on. This grade is significant and, with it occurring early in the race, most athletes will likely spike their heart rate/power significantly. If you are passing folks on this climb, you’re probably pacing sub-optimally. Temperatures will likely be cool to pleasant in the early bike but will warm up quickly. Once heart rates are settled, use this period to get ahead on hydration.

    Section 2: “Easy Aero” (66 to CR 13).
    This is the fastest section of the course, a net downhill. Speeds will be high and athletes will feel good. The temptation at this point will be to be of the mindset “this is easy, I’m going to crush this bike split”. Don’t be fooled. The hard section of the course is still to come. Enjoy the speed that you are getting at relatively easy output, but in the words of my buddy, Justin – “Don’t go looking for work”. It will come! From a pacing perspective, most AGers will be best served by sticking to their easy (Zone 1) power/HR band for the bulk of this section, with a focus on staying aero and (legally) surfing those competitors who are pacing inappropriately and rolling past. Both average heart rate and power should be at the lowest points of the bike at the completion of this section, giving you plenty of room to elevate in the closing stretches. There is one scenic short climb that is an enjoyable ‘stretch break’ during this section from km 45-50 along CR12. This is the most scenic section of the course Take a look around and enjoy it. There are some sustained periods of less exciting scenery ahead

    Section 3: CR 13 to T2 (The work begins!)
    This is the section of the course that I live closest to and I have had my 'hundred battles' on it - some won, most lost. It is deceptively difficult, especially late in a long ride. Despite the relatively low net elevation gain of the course, it is not a ‘flat’ course like Florida or Arizona. Nor is it a momentum rolling course like Louisville. You are basically rolling slightly down (heading away from the mtns) or slightly up (heading towards the mtns) the whole time. From 100k to the finish, you’re rolling up! The road is pushing against you fairly consistently during this period & you will want the legs to push back! This is the section of the course where athletes who have saved sufficient energy to draw on some Zone 3 (Moderately-Hard) will be rewarded. This Zone 3+ effort will be a necessity for the bulk of athletes on the steepest pitch of the course, as the athletes turn off Hwy 52 and head to lookout road. You will want some legs for this period of the race. Following this, there is a relatively flat roll through downtown Boulder to the high school where you will begin the run.

    Winds typically are Easterly and pick up through the day. The exception would be if an early storm blows in over the mountains. If this is the case, it generally leads to Westerly winds that are quite strong and would be blowing straight at you as you roll back into town along highway 52. Prepare yourself for this possibility. If you are already ‘fragile’ at this point, It will make for a very tough day!

    The general pattern of the 2 loop run course is similar to the bike – slight downhill as the athletes head away from the mountains, followed by a slight uphill as athletes head back towards the mtns. Athletes will enjoy the slight downhill start as they roll out of Boulder high school and along the cool waters of the Boulder creek. This pleasant phase is short lived, however, as athletes will make a turn off the creek path to begin the first of the ‘tack ons’ that race organizers added following the Boulder floods. This first tack on (~3 to 8K) is a slight net uphill grade on the way out that is not particularly obvious. It just ‘feels’ like work after coming off the pleasant downhill of the path. Athletes will likely ‘over cook’ this part of the course as they start to feel as though they are moving too slow following the grade assisted section of the BCP.

    Runners then roll back towards the path for a short stretch before beginning the only significant hill in the course as they climb the foothills parkway overpass. This is the most exposed, least ‘pleasant’ section of the course. Many athletes will be well served to add a walk break at this point. Following the overpass, the athletes roll down Pearl Parkway on a net downhill to the turn around. Following the turnaround, the work begins!

    From ~11K to ~18K (33 to 40K on lap 2) is the longest consistent uphill stretch as athletes head back ‘up the creek’. This isn’t so much a hill as a ‘slow section’ of the course. It’s sheltered and cooler than the more exposed sections, but from a pace perspective, just be prepared to see slower paces on this section of the course. This long period of ‘feeling slow’ may be tough on those athletes that have paced sub-optimally to that point, and this is the perfect section to make a lot of passes if you’re feeling good. This is especially the case on lap 2. Passes here will stick! The path winds and twists and when passes are made it will quickly be a case of “out of sight, out of mind”. Running to pace will be particularly demoralizing on a course like this. With the grade differentials and the impact of altitude, I would advise all athletes to pay close attention to heart rate on both bike and run.

    The grade progressively increases a little more as athletes approach the 2nd turn around at Eben G Fine Park. This would be another good spot for a well placed walk break. Following this turnaround, the athlete hits the fastest section of the course as they roll downhill back to the starting point at Boulder High School, before beginning lap 2. You will want to have the legs to run here with good cadence for an extended period of time. While the speed differential between running hard and ‘turning the legs over’ won’t be that great, the difference between walking and running here will be large. The course is almost all concrete and with the grades, could be tough on the legs & feet. Be sure to train this aspect with some uphill/downhill running.

    In many ways, this course is a perfect example of a course where ‘back end loading’ your effort is rewarded. The toughest parts of the course will be in the latter sections of both the bike and run. Arriving at these points ‘ready to work’, will be rewarded.

    For our Endurance Corner profile of Ironman Boulder from local pro, Justin Daerr, click here

    To hear Justin, Gordo and I chat about some of the challenges of racing at altitude along with some more course specifics, click here

    Race smart!



    Carbohydrate Loading for Ironman Athletes.

    Alan Couzens, MS (Sports Science)

    May 30, 2014

    In my previous post, I weighed in a little on the LCHF debate. As I outlined in the post, valid arguments can certainly be made for moderating the carbohydrate intake during the bulk of the training phase for most athletes. However, as we move from training to taper, different considerations emerge that will have impact on the optimal pre-race diet for the endurance athlete.

    Studies have consistently shown a strong relationship between starting CHO stores and time to fatigue at submaximal intensities. For example, Balsom et al., (1999) found a 50% decrease in time to fatigue when subjects began an exercise test with a 50% reduction in glycogen stores. This almost linear relationship between starting glycogen stores and time to fatigue has been observed in numerous studies. Therefore, a key objective heading into your A-Race is to maximize this adaptation. The good news is that it doesn’t take a lot of time or effort to maximize this adaptation. However, it does require doing things a little bit differently to your normal training and nutritional routine and perhaps a little different to a normal taper routine for a shorter distance athlete.

    Ironman legend, Torbjorn Sindballe comments on some of the differences here...

    “ If I only did shorter sessions for the few weeks leading into a race, I often felt super fresh but lost my momentum after hour three or four in the race. To combat this, I implemented a big rest phase to reduce fatigue several weeks before a big race and then did a series of more normal training sessions in the weeks leading up to the race”


    What he’s referring to is a very real physiological phenomenon of metabolic detraining. While, most physiological adaptations can be sustained on relatively minimal volume for 3-4 weeks, if an athlete does not ‘challenge’ the ability to hold on to larger than normal glycogen stores, it is an adaptation that is lost rather quickly. A typical rate of ‘metabolic detraining’ is shown in the chart below (data from Casey et al., 1995).

    In the absence of sufficient stimuli, the body will lose 10% of its glycogen stores within 2 weeks (more if the lack of long rides extends into other weeks!) & you will lose 10% or more from your time to fatigue! For this reason, including regular moderately long sessions, even relatively close to an Ironman, is a very worthwhile strategy for the serious Ironman athlete, as suggested by Torbjorn. However, it is not just the shift in race week training that will enable you to elevate your glycogen levels to new highs. The training must be accompanied by a similarly appropriate nutritional strategy.

    To increase your body’s receptiveness to storing glycogen, demands a little bit of a departure from a normal taper routine in both training and nutrition. Here is what I suggest for the long course athlete…