Energy Pacing your Ironman III

"Although mechanical energy is indestructible, there is a universal tendency to its dissipation, which produces throughout the system a gradual augmentation and diffusion of heat, cessation of motion and exhaustion of the potential energy of the material Universe"
- Lord Kelvin

Today I would like to address the last piece in the puzzle of optimally pacing your Ironman. So far we have looked at how to go about determining the optimal bike/run energy allocation for different courses and athletes. However, we haven’t yet looked at how to go about determining how much actual energy you have at your disposal, i.e. how much potential energy do you have available in your personal system, or put more succinctly, what are your energy reserves?

This is a more complex question than it appears at face value and is a function of things like:
• Training
• Nutrition
• ‘Freshness’
• Muscle Mass
• Duration of your event.

Let’s take a look at a couple of these factors individually.

Muscle Mass/Training

Well trained muscle typically stores ~700mmol of glycogen (per kg of dry weight) (Starling et al 1997, Adamo et al. 1998). This equates to ~20kcal/lb of muscle. So, for a mesomorphic (Muscular) 165lb male with 75lb muscle mass, typical muscle glycogen stores are in the range of 1500kcal.

Add to this liver & blood glycogen and glucose stores of ~500kcal and a well trained athlete of average size has approximately 2000kcal at their disposal. It should be noted that an untrained individual typically stores approximately half of this amount.

Duration of the Event

In addition to having access to these stores at the start line, the intelligent athlete will take in an optimal amount of carbohydrate during the event that will lead to an additional 240-280kcal/hr of energy at their disposal.

This implies that the longer the event continues, the larger the total energy pool that the athlete can draw from assuming all other factors (such as rate of CHO absorption) are equal. This is important to remember when we are comparing the energy demands of athletes with different race durations and has practical significance when attempting to define a TSS ‘budget’ for the athlete.

In power training terms, some coaches have hypothesized that there is a TSS ‘budget’ that is optimal for all athletes to observe during the bike portion of the event. This is generally recommended to be in the vicinity of 280TSS. Thus, depending on anticipated bike split duration, the intensity of the bike leg is manipulated to assure that the athlete doesn’t exceed 280TSS over their total race duration. For athletes in the 5.5-6.5hr bike split range, this then results in an intensity factor of 0.65-0.71, or, with typical Ironman variability indices, an average power of 60-68% of FTP.

However, while this is a good starting point for many athletes, it does not take into account some of the individual considerations mentioned above.
A good rule of thumb that I have found to work quite well when comparing power data in the field with lab data is:

1TSS = 10kcal of glycogen.

In other words, a bike of 280TSS would be approximately equivalent to 2800kcal of glycogen/glucose output. So, for our hypothetical 165lb guy above, riding at an IF of 0.68 for an ~ 5:43 bike split, he starts with 2000kcal and gets 240-280kcal/hr on the bike. His input would be 2000 (starting energy) + 1500 (@260/hr) for a total of 3500cals. With an output of 2800kcal, this leaves him ~700kcal or 70TSS when starting the run. Even with an extra 260kcal or 26TSS/hr in exogenous CHO during the run, the picture isn’t pretty. For a 4hr run this is 180TSS or 45TSS/hr @ an IF of 0.67. Unless you’re working with an FTP pace of 6:15 or better, ain’t gonna happen.

Nope, far more typical is the 5hr marathon that allows for an extra 26TSS and a more manageable IF of 0.64 for an athlete with an FTP of ~7:20. As outlined in my previous blog, a 6hr bike/5hr run is not the best way to distribute your energy, yet it is almost inevitable for the average athlete who approaches the bike with a desire to ride at the typically recommended IF/AP power numbers.

In my experience, for the majority of courses, a far better way for most athletes to distribute their energy is to split their TSS budget down the middle and devote half to the bike and half to the run (for most folks, the swim should be done so easily that it’s energy output is non-significant). So, for our hypothetical lean mean 165lb male Ironman with starting glycogen stores of ~2000kcal/200TSS and a predicted finish time of ~12hrs (meaning an additional 11x260kcal/hr in exogenous glucose), his energy reserves are in the range of ~480TSS. If this is split at 240 for the bike and 240 for the run, we would expect our ‘average’ athlete with an FTP of 7:20/mi on the run and 240 on the bike to run a 4:25 marathon at an IF of 0.72 and bike a 6:05/144W bike at an IF of 0.6.

So, to summarize the difference in approaches:

Typical (Bike-heavy energy split)
Bike = 280TSS @ an IF of 0.68
Run = 200TSS @ an IF of 0.64
Splits: 1:00/5:45/5:00 = ~12:00 :-(

Optimal (Even energy split)
Bike = 240TSS @ an IF of 0.6
Run = 240TSS @ an IF of 0.72
Splits: 1:00/6:05/4:25 = ~11:45 :-)

As outlined in a previous blog, the effect of holding back 10% on the bike is magnified for faster athletes, with differences of 30 minutes or more expected at the pointy end of the field. Plus being the passer rather than the passee on the run is a much more enjoyable way to race :-)

So, to summarize the 2 steps are:
1. Determine your total energy reserves
2. Split it down the middle and devote half to the bike and half to the run.

While the theoretical considerations mentioned above provide a good starting point in coming up with pacing targets for the limited number of race simulations that you do prior to your event, the best way to fine tune your pacing targets is to prove their validity in training and C races.

Athletes can expect a 20-30% supercompensation of glycogen stores when tapering for their A-race (Shepley et al. 1992). Therefore, the best way to verify your true energy reserves is with slightly under-distance time trials of >2/3 race distance/duration.

In the above example, where we are targeting a race day energy output of 480TSS, I would expect the athlete to PROVE their ability to perform a big day of training of at least 320TSS (2/3 race duration) at the target racing intensities prior to their event. If the athlete is only able to manage a big day of 280TSS in the context of a normal training week, then I would amend the target race intensities accordingly.

As mentioned above, novice athletes or detrained athletes can have <50% of the glycogen storage capabilities of trained athletes. In practical terms, this manifests as 150 or 200TSS being a ‘big day’ in the early season. It should not be assumed that the athlete has a tolerance to 280TSS, 350TSS or 500TSS. It should be PROVEN.

In this way, theory meets practice and the athlete’s actual energy reserves are assessed.

Hopefully, this article will provide athletes with the final piece in the puzzle when determining how to optimally pace their Ironman. There is a lot of free speed out there for the athlete who is brave enough to bet on their ability to finish strong by holding back on the bike. However, like most things related to Ironman, while this is a simple principle, it is anything but easy. But, as Gordo is fond of saying, there is no easy way!

Race Smart.

AC

Two Steps Forward, One Step Back.

While in the midst of preparing a couple of lengthy articles on anatomical considerations in bike fit (and the midst of a bit of personal overreaching :-), I thought I would post a short but (if I do say so myself) profound article on a key concept that I have come to realize and implement with my athletes over the previous year.

The concept is simply stated as: The optimal load for a given athlete is one which allows that athlete to take at least 2 steps forward (in fitness) before taking one back (in recovery).

A short wiki search revealed that the origin of the term – 2 steps forward, one step back, is found in a very apropos metaphor of a frog trapped in a well. For every 2 jumps forward, he slides down the slippery wall and loses some ground, but even so, with determination, net progress is made and there is a happy ending to the tale as Kermit makes the final leap out of the well.

The concept is equally applicable to athletics, as, just like a slippery well, taking time to fall back and lose some training load as the body converts the previous load into fitness is inevitable & necessary.

Additionally, the concept is applicable on all levels of the training cycle.
The most obvious 2:1 application to the training cycle is at the mesocyclic level, i.e. the coach/athlete should select a training load that allows the athlete to put forth at least 2 good weeks of training before a week of lower volume is needed. In a former post, I outlined just how much fitness is lost during long periods of rest/reduced training. The serious athlete should be very careful to limit the frequency of back to back recovery weeks to no more than 2-3 per year (at the end of each season). 2 weeks of de-training in the middle of the season will result in an ~30% fitness loss. A loss that will take 6 weeks of training to merely get back! I have personally experienced this in my 09 prep. After a challenging camp in April (31 hrs of training in a week), my CTL and my aerobic time trial numbers peaked up nicely. However, after being forced to take 2 weeks of recovery after that camp with some lingering lethargy, even now, 9 weeks post, I am yet to return to my camp fitness. A more moderate 20-25hrs, while still challenging, would probably have enabled me to limit recovery to one week and thus enable me to continue building on this fitness.

Perhaps more significant to the world of age group athletics, this principle is even more important in a microcycle/weekly context. The serious athlete should never do a mid-season training session that requires more than 2 days/48hrs recovery. For a typical AG athlete in the middle of the season, 50% of the fitness benefits of a given key workout is lost within 24hrs. However, this still represents a 1-3% net fitness improvement so it’s a good deal. However, if the athlete goes just a little too hard, necessitating 48hrs of recovery almost ALL of the fitness benefits are lost. For this reason, no workout should come close to the demands of a race no matter how much goading your training buddies are capable of. Save racing for races! (And save racing until you’re fit enough to keep race recovery to a minimum).

On the macrocycle level, that athlete should never have 2 months of training lower than their average training volume. IOW, the athlete should take a short rest after each season and before experiencing long-term burn-out. After a demanding season, it will typically take an athlete 4-6 weeks to completely shed the accumulated fatigue. At this point, the athlete is still holding onto ~40% of their accumulated fitness from the season. However, if the athlete extends the transitional period to 2 months instead of 1, only 20% of fitness remains. In a long term developmental sense, it is this small year to year carry over in fitness that builds champions. On a related note, the athlete should do all that is necessary to minimize the risk of a long-term injury. Any athlete who is forced to take a multi-month (3mth+) break is ostensibly ‘starting from scratch’.

The great Emil Zatopek once likened the training process to pulling on a spring. Pull just the right amount and POW, the spring will retract beyond it’s starting point. Pull a little too much and you break the spring. Take care of your springs and…

Train Smart.

AC

Checking the Box

“Although Seb was quite nimble, due to his slim physique, his running showed a significant lack of endurance. To remedy this, some distance training and participation in cross-country was indicated…… As Seb progressed, a positive effort was made to improve the balance between his speed and endurance but neither one at the expense of the other”
- Peter Coe (Coach and father of running legend, Sebatian Coe)

There are a number of decisions that we must make as coaches and self-coached athletes including
• How Much? (Volume)
• How Hard? (Intensity)
• And, not unimportantly, what type of training should make up this volume/intensity mix.

There is much debate on which training form/intensity is ‘ideal’, ranging from the low intensity advocates , the medium intensity ‘sweet spot’ group and the high intensity/threshold proponents.

Additionally, orthodox proponents of the periodization faith recommend that the form of training emphasised should change through the training cycle in accordance with the competition calendar.

Regular readers of this blog will hopefully have come to the conclusion that I am not a proponent of emphasizing any one intensity zone. Rather, I believe that long term athletic development is contingent on a very balanced training approach, with a vigilant, conscious effort being made to never over-emphasize one physiological quality or zone at the expense of another. I am not alone in this stance. Rob DeCastella’s coach, Pat Clohessy was one of the pioneers of this multi-speed approach. Likewise, Peter Coe used a similar approach to train his son, Sebastian, in an event that was over 2hrs less than Deek’s.

Additionally, on the whole, I do not believe in arbitrarily changing the training mix just because the calendar ticks over into the next month. While for advanced athletes, there are advantages to sharpening training, most athletes will be better served spending their precious time and training energy focusing on addressing their specific limiters unless and until they are ‘fixed’.

I have seen far too many athletes come through our lab with either a very strong top end/very weak base or vice versa to conclude that any one training intensity is right for all. There is no ‘right’ intensity, only a right prescription for a given athlete at a given time.

So, this is all fine and dandy if we have the means to undergo rigorous lab testing each mesocycle but if we don’t have access to this, how do we go about determining how ‘balanced’ an athlete is at any given time in the field?

I like to look at each athletes power-duration and pace-duration curves as a good starting point. In a previous post I looked at what an ideal pace-duration curve looks like and how it slightly differs for Ironman athletes. My ideal ‘ironman’ curve is presented below.



I have had a number of real ‘aha’ moments during my coaching journey. One key revelation came when I came to the realization that there is only a slight difference in threshold abilities of the very best ultra-distance athletes and the very best distance athletes. IOW, it is important to every athlete’s long term development that appropriate attention is given to functional threshold development.

The differences between a distance curve and an ultra curve are slight and are primarily related to the ‘tail’ of the curve, i.e. for very long durations, I expect an Iron-trained athlete to better be able to hold a higher % of their threshold pace or power (see below). However, just because these differences are small, this does not diminish the fact that they are crucial to the athlete’s target event.

This expectation is not particularly revolutionary. Of course, we would expect that an Ironman athlete will be faster over distances that come closer to race duration providing they are appropriately trained. This small print is included in many of the training systems out there, usually in the form of, ‘the athlete with the highest functional threshold pace/power will also be faster over all greater distances – providing they are appropriately trained. The difference between my system and the others is that I demand my athletes PROVE they are appropriately trained before moving up to the next level.

It should be noted that while the 'tail end' demands of athletes training for shorter distance events are less challenging than for long distance events, at least in my world, they are still DEMANDS. IOW, even a short course athlete must prove the ability to execute a medium-long run at an appropriate intensity before moving up, irrespective of what they can do for a 5K test.

Let me provide an example for an Ironman athlete taken from the curve above. Rather than scheduling an FTP test every 4 weeks and moving all training paces up in accordance with this one point on the curve, I expect my athletes to complete all appropriate points on the curve before moving up. This does not mean that an athlete must complete a race pace session over full race duration before moving up. If this were the case, the athlete would constantly be tapering for and recovering from his test sets and never have time to train :-) But it does mean that the athlete will complete an appropriate % of the target race duration at the appropriate pace without it destroying their week before we raise the top end goals. Some examples of macrocycle goals from one of my top AG Ironman athlete’s run training (FTP pace = 6:30):

• 50mi week in <6:40
• 20mi Long Run (day after long ride) in <2:30
• 20mi Quality Long Run w/last 10 @ 7:00
• 2x3mi tempo in 19:30 w/5min recovery
• 10x800 in 2:50 w/3min recovery
• 10x200 in 40s w/50s recovery

Depending on the type of training emphasized, a ‘top end’ fit athlete may achieve the last 3 goals and a 6:25 FTP test within the first mesocycle. But if the athlete can not hold an appropriate % of that FTP for near race durations, what is the point of moving up? Indeed, what is the point of even testing again until the athlete can do so? If an athlete is ‘unbalanced’ with respect to their event, it may take 2 or more seasons, to bring the curve back ‘in balance’. I am fine with that. Because not allowing time for your bottom end to catch up to your top end fitness is a dangerous slippery slope to failing development that has been proven time and time again. Think back to the negative effects on US distance running when threshold and interval training was emphasized to the exclusion of the LSD miles that made up a high proportion of the training regimens of America’s most successful distance runners (to date!!!)

So, let’s get down to brass tacks. What does this look like in terms of a mesocycle? Put simply, the athlete winds up repeating the sessions that they are most weak in several times within the mesocycle(or macrocycle) until they have ‘checked the box’. For example, in the first week of the cycle, the 2 key sessions may be devoted to a functional threshold bike and a repetition run workout. If the ‘box is checked’, these workouts shift to maintenance emphasis in the following microcycle while another goal is targeted. For argument’s sake let’s say a tempo bike. If the box is not checked on the tempo bike, for example the athlete is scheduled for 3x25min @ LT watts and flunks the last, the next key workout will again be devoted to tempo with a more manageable duration. So the athlete may wind up with 3,4,5,6 weeks of tempo emphasis within a macrocycle. In this way, the athlete’s key sessions are devoted to their personal weaknesses (with respect to their event) and long term balanced development in ensured.

I’m sure that if you were to ask 5 athletes that I work with to give a concise description of what my training plan is like, you would get 5 different answers. To some, I’m probably seen as a mileage junkie, while to others, the chief of the intensity police :-) The secret is, I don’t have a universal training philosophy other than to mirror the athlete’s needs. The only universality that exists in elite coaching is a universal ability of the best coaches in the world to ‘size up’ an athlete, determine their personal strengths and weaknesses and apply this information to selecting an appropriate training means and an appropriate event.

Train smart.

AC