Iron Math: Calories and Why The Back Half of an IM Marathon Is So Damn Hard

I was recently trying to explain to someone that has little-to-no familiarity with endurance sports why the back half of an Ironman marathon is so hard.  In an attempt to put things in a more common and quantifiable language, I decided to frame my explanation in calories. I'd never thought through this on my own, and while the results certainly are not surprising, they illustrate why things tend to get so hard into the afternoon of an Ironman. Here is a summary of the conversation and the math.  Please note I'm not a scientist and a lot of this is based on assumptions, which in turn are based on various articles I've read; so while my analysis is far from precise, I am confident it is directionally correct.

Race Morning: Let's say I nail my carb-load and pre-race nutrition pretty well and start the race in a fully loaded state. I am going to call this having 2200 calories on board. I've seen a whole bunch of research that seems to center on a 'maxed out' carb load state between 2000-2800 calories, and given that I don't live in a lab, I think the lower end of the range most likely reflects my reality.

Swim: For the hour and change (and a bit of change in my case) it takes to swim 2.4 miles, I am going to assume I burn 700 calories. Thus, I'll finish the swim with 1500 calories on board which probably explains why I feel so good getting on the bike!

Bike: Based on an accurate power meter reading, I'm fairly certain I burn 700 calories an hour while riding. I am consuming 450 calories an hour of straight carbohydrate.  I am going to be generous and assume I'm actually absorbing 400 of those calories (research here says the upper limit of absorption per hour is 100 grams of CHO, or 400 calories, so this is a very aggressive estimate, but it's also a nice round number).  So, 700-400 = 300 calories net burn in every hour.  My IM bike took a bit under 5 hours, which means I had a net loss of 1500 calories (300x5) on the bike, so I'll finish the bike even.  Not ideal for starting a marathon (just think about starting an open marathon after eating a low-carb diet for 3 days), but not terrible either, which explains why most (myself included) feel pretty good in those first few miles of the run.

Run: Now this won't be as accurate as the power meter data from the bike, but running at between 7:50-8:30 pace (my range this last IM) and in fairly hot conditions, I'll estimate a burn of about 800 calories per hour. Between sips of sports-drink at aid stations and energy gels, I probably consume around 250-300 calories an hour on the run...so I'll call it 275, and this is all carbohydrate.  Let's say I absorb 250 of these calories (again, super generous, but keeping numbers round).  With this burn and replacement, I'm running a net deficit of 550 calories an hour.  Here is how that shakes out over the course of the run:

• 1 hour (7.5 miles) 550 calorie hole
• 2 hours (15 miles) 1100 calorie hole
• 3 hours (21.5 miles in, I've slowed down a bit) 1650 calorie hole
• 3-3.5 hours (to race finish) the hole grows to 2200 calories as it is becoming harder to take down anything, and the time it takes to absorb carbohydrate becomes greater than the remaining time left in the race.

Like I said in opening, this should not be surprising; the back half of an IM marathon is hard! But I do find this back-of-the-envelope analysis a nice and straight forward way to understand why most start to feel a big drop-off in overall energy around mile 13-15.

A few notes: This model assumes a lot, including that 100% of energy during the race is coming from carbohydrate stores.  I'm sure (because I've seen Alan Couzens' charts) that some of the burn is coming from fat, but probably a pretty minimal amount at the watts I'm riding (200-215) and pace I'm running (7:50-8:30).  Also, every individual is different in their metabolism and the strain that respective pacing places on their energy systems; so while this cannot be applied with any precision, from a thematic standpoint, this story holds true for any athlete that is "racing hard," whatever his or her hard might mean in watts, pace, etc.

What this means to me: I think Mirinda Carfrae said it best on the recent NBC Ironman special.  When asked what is going through her mind during the run, she simply said "Eat. Drink. Run."   The IM marathon is a beast with fangs, and all energy should be used on running, and if not running, making sure you eat and drink. Carfrae nailed it, and she is a total killer, and I have a mini-crush on her because of it (sorry Caitlin).

Final interesting thing: This type of approach to thinking about the IM marathon explains why when top-end professional's blow up, they often end up walking or DNFing, whereas for many age-groupers, at "blow-up point" the run turns into a jog which turns into a shuffle.  For the former, with body fat % that is extremely low, there isn't a lot of fat on board so literally the tank becomes empty and the car stops.  For age-groupers, even the pretty lean (e.g,. 7% body fat and up) there is enough usable body fat on board to fuel the end of the run, just at a significantly reduced pace.

My Fueling Strategy: Drink From Your Bottles, Eat From Your Pockets(ish)

I am totally pumped to be partnering with Nuun as an athlete ambassador for the amateur triathlon market in 2013!! But this has led to I guess a rather obvious question coming from more than a few other athletes: How is it that you can be linked up with two sports drinks?  Isn't there a clear conflict of interest?

The short answer is no.  The longer answer is that Greater > Than and Nuun serve completely different purposes in support of my training and racing.  This got me thinking that I would share some further detail...not to clear up confusion about my partner support (because c'mon, who really cares) but more-so to reiterate the point that when it comes to high performance endurance athletics, there is no one-size-fits-all approach to fueling and nutrition, and minor differences can go a long way.

In short, I subscribe to a fueling strategy (e.g., my hydration and nutrition while actually training and racing) coined by nutritionist Stacy Sims: Drink From Your Bottles, Eat From Your Pockets. Basically, I use liquids as a source of hydration and electrolytes, and solids and semi-solids as a source of calories; mainly carbohydrates.  This took me over a year and tons of diarrhea while running to figure out, but for whatever reason (and there are tons of reasons in the scientific literature if you are interested and search) my stomach simply can't tolerate calorie rich liquids while going hard.  So, Nuun is my go-to hydration source given it contains virtually no calories, but a perfect (literally, because it is customizable by breaking up the tablets) balance of electrolytes that compliments the calories (again, mainly carbohydrates) that I get from solids and semi-solids (Clif shots and shot-blocks, chunks of Clifbars, etc).  This is not at all about brand loyalty, price, or anything like that.  The combination of Nuun and Clif solids is the only thing that works for me when my HR is above 120 BPM and there is running involved after biking.  Even if I got no support from these companies, I would still use their products exclusively...or end up spending a quarter of my race in the Porta-Jon, and nobody likes that.

When it comes to recovery and prep (e.g,. what I consume right after workouts and in the lead-up to races)  Greater > Than is a critical part of the equation.  For recovery purposes, the electrolyte balance with a heavy focus on potassium plus the Sucrose carbohydrate source jump-starts the body's adaptation process and quickly gets things moving back toward homeostasis.  I've actually heard more than a few times now that Coconut Water is second to intravenous fluids when it comes to immediate recovery after hard physical efforts. I pair this with Extreme Endurance XEcute which provides protein and lactate to help stimulate muscle repair.   In terms of prep, in the days leading up to a longer race when I am shooting for massive amounts of carbohydrates, being able to get some of these carbs from a liquid source helps me avoid bloating and a feeling of total heaviness, and also, given Greater > Than still doesn't have as much sugar as the other leading performance sports drinks, I don't get the adverse blood sugar effects that have left me feeling crappy during carb-loads in the past when using other products.

So, there you have it.  Not conflicted at all, and so fortunate to have the best products in my corner!

5 Simple Food Rules for Endurance Athletes

It is the time of year when triathletes all over are emerging from their "shutdown time" or "off-seasons" (which, let's be honest, are really off-weeks for most of us) and getting back into training.  Personally, between the structure of my race schedule for next year and a minor hip injury, I was off for a bit longer than planned, and have emerged with significantly more of me than I would have liked.  While this is a minor problem that can be alleviated with a month of solid aerobic training and somewhat selective eating, it forced a pause for reflection and got me thinking about my nutrition more broadly, which I identified as a limiter last year.  Long story short, I ate a lot of the wrong foods at the wrong times.  I'm sure that this compromised both my workout prep and recovery, and thus had a sub-optimal impact on my performance over a season.

There is so much out there re; nutrition for endurance athletes that it can actually get a bit overwhelming, but I really think it can be boiled down to a few simple rules.  Stick to the below and by-and-large, an athlete should set themselves up for both performance and good health.  In the spirit of full transparency (and because I am marrying an attorney) I have no formal background in nutrition nor certifications in the topic.  These rules are just my take as an athlete trying to make sense of all that is out there and to make it as actionable as possible.  Also note, while simple to write and speak about, these rules can be quite hard to follow.

Rule 1: Don't eat sugar unless it is immediately before, during, or immediately after a workout...or, if the source of the sugar is a fruit.  Yes, there is some sugar in good-for-you foods like Greek Yogurt which is fine, but I'm talking about the Lucky Charms kind of sugar and the fruit-on-the-bottom sugar...cut that out...

Rule 2: When consuming carbohydrates [especially grains], attempt to eat only true whole grains/foods such as brown rice, quinoa, non-processed breads, potatoes and unlimited vegetables. If you are going to deviate from this, do so sparingly, and ideally, in the meal following a long training session.

Rule 3: Attempt to meet all caloric targets by 90 minutes prior to bed-time.  There is nothing wrong with a late-night snack, but keep it small, and ideally, something slow to digest; e.g., casein protein which is in yogurt [or can be purchased in powder form] with some fruit.

Rule 4: Count calories, but not all the time! It is good to "obsess about calories" but *only for short periods of time* so that you can uncover weaknesses in your diet.  For example, I found that I can get into ruts where I eat 50% of my calories after 7PM...not good...big violation of Rule #3. 

Rule 5: If you are intentionally trying to lose weight, be smart and very scientific about this.  Timing is everything, and weight-loss cannot be separated from periodization in training.  Remember that while lighter can mean faster faster, stress fractures, illness, and chronic fatigue are always slower...

There you have it.  Nutrition in 5 simple rules.  Note that this is separate from "fueling" which is what you consume during workouts, and is actually far more complicated in my opinion.

The Importance of A Post-Workout Snack

A few of the runners that I coach are entering into some pretty serious phases of training; where both intensity and volume are picking up, creating a significant increase in overall training stress. While I have no doubt that they will attack the workouts hard, wear their compression socks 24/7, foam roll, schedule massage, etc, etc, I wanted to make sure that they don't overlook the simplest, yet arguably most important (second to good sleep) thing that they can be doing to prime themselves for success. Before going any further, I'll note that a recent "tweet" from a mentor of mine, Matt Dixon, helped trigger this "back to basics" thinking. Matt said "I'm bemused by the focus placed on compression + ice + stretching, but ignore proper fueling, sleep, and lighter training sessions." The rest of this brief, practical, and to-the-point post focuses on what I think is the most critical element of fueling; the importance of a post-workout recovery snack. I have simply copied the relevant parts of a note I sent to my athletes below, since the information is applicable to all endurance athletes that train hard and consistently:

I know you guys will attack the workouts hard, but I want to stress the importance of what you do right after those workouts. It becomes critical to have a recovery snack within 45 minutes of completing any hard (whether it be higher in intensity or longer in duration) workout. It is within this 0-45 minute window that your body is most "open" and "receptive" to taking in carbohydrate and turning it into glycogen (the stuff that powers your body during training), which is then quickly stored in your muscles so it can be used to fuel your next session. Think of your muscles like sponges; after finishing a hard workout they are squishy, soft, and porous, so you can really load them up (so they will be full for the next workout), whereas once time passes, they become dry and harder, and they don't fill up as easily or fully. There is a ton more to say here on what neglecting the post-workout snack means for your overall metabolic health and body composition, but just know that it is not only critical to your performance, but important for other more high-level health reasons too.

In terms of performance; this may be a slight exaggeration, but one of the most important factors of how you perform on your Sunday long run will be what you ate in the "fueling window" after your hard Friday threshold session. If timing works out so that you are eating a proper meal in that window, great! If not, aim for 50-60g of carbs and 10-20g of protein in a quick snack. This can be as simple as a cliff-bar and a banana, a large glass of chocolate milk, or something off-the-shelf like a Gatorade recovery drink...or... it can be as exquisite as some fancy smoothie you cook up; it's your world, so long as the focus on timing (fast) and the carb/protein ratio (4 to 1) remains.

I know the tendency is to "wait it out until breakfast/lunch/dinner" and then really go nuts, but your body needs and can best use the stuff right away, so put it in there right after, and just eat a little less later. That cliff-bar does you so much more good right after a workout than it does you at 10:00pm right before bed...

As I mentioned above, the above is most important for high-intensity or high volume days. If truly run for the purpose of recovery, easy runs shouldn't stress the body enough to deplete glycogen stores, so while I would encourage a quick snack after those too, the priority of nailing the post-workout snack is on anything at or above threshold or after long runs; both cases where you are likely to be in a glycogen depleted state. I'll also note here that for longer duration workouts, your fueling during the workout has a similar effect. Being a hero and regularly getting through your long workouts on just water sabotages long-term fitness gains. Use a sports-drink and other sources of carbohydrates.

Preventing complete glycogen depletion, and working to refuel your "muscle sponges" is the best combination for consistent, healthy, effective, and performance enhancing training.

4 Pillars of Holistic Training: Nutrition

First off - sorry for the hiatus. When you (and I) look back to my last post, you may be upset (and I, somewhat embarrassed) that it has been 6 weeks. No need to waste more time with a long explanation, I've just been very busy with a number of things. Good news for everyone is that you can simply look back to the last 2 posts to refresh yourself of where we are at in our discussion of the 4 pillars of performance (1. sport-specific training, 2. functional strength, 3.nutrition, and 4.recovery). Today, we focus on nutrition. Much like with the prior posts, this should simply serve as a primer on a very complex topic, and I encourage you to take what you read below, and continue to educate yourself. Hopefully, if nothing more, the following helps you target your search for future information. OK, onto the good stuff.

Nutrition is of huge importance. You are what you eat, and you train and race what you are. The decisions that we make about what to eat and, as you'll read below, when to eat it, are pivotal to our immediate performance (e.g., hitting targets in a workout or race), long-term performance (e.g., getting to an ideal body weight and composition, recovering from and adapting to hard training), and overall general health (e.g., feeling good everyday, and setting ourselves up for long and high-quality lives). With so much going on here, I am going to make an initial cut to make this all a little bit easier to digest (no pun intended) by breaking this discussion of nutrition for athletes down into 2 parts:

1) Fueling: What we eat right before, during, and right after a workout

2) Nutrition: What we eat the rest of the day

1) Fueling

First I will introduce the concept of a "workout window," which is the period of time encompassing the 30 minutes before a workout, the total time of the workout, and the 30 minutes after a workout. The baseline understanding everyone needs is this: muscles run off of carbohydrates, and can store enough energy to get through between 70 and 90 minutes (depending on the individual) of training. So, if you have a longer workout, you have to refuel yourself as the training session goes on. If you are under that 90-70 minute mark, you may not need to fuel during your workout, but should still focus on the "right before" and "right after" portions of this post. Even if your workout is short and you don't need to take in calories, you should be drinking water for hydration during any workout, about 24-32oz/hour (if you want a more exact number, Google "sweat rates for athletes" and perform a sweat test.

- 30 minutes before a workout: 2 things are most important about this. The first is that whatever you eat, your gut needs to be able to tolerate it easily and digest it fast. No one wants to enter a workout feeling bloated, with a stomach ache, or nervous about having to poop. The second thing is this meal should be dominated by simple carbs. Like I said above, your body runs off of carbs, so proteins and fats in this time period are pointless. And, within carbs, the importance of simple carbs is huge. Complex carbs (e.g., brown rice, brown anything) take longer for the body to breakdown whereas simple carbs (e.g., most white things, sugars) are available for use by the body much quicker. In this instance, right before training, we want to top off our muscle stores (from the previous meal) with readily available carbs that we can use asap.

- During a workout: Same 2 things mentioned above (tolerable and simple carbs) apply, but with even more importance on both. To those ends, we have an array of sports drinks and sports solids (Gus, Powerbars, etc) -- giving us what we need in an easy way to digest -- to choose from. While there are many equations out there, a good general rule here is to aim for between 2 and 3 calories (again, dominated by simple carbohydrates) for every pound of lean adjusted body weight. So, for an athlete that ways 160 pounds and is 10% body fat: 160-16=144, 144*2/3 = between 288 and 432 calories per hour. Ideally, you want to aim for the upper end of this threshold, but meeting the first criteria; it has to be tolerable. Much like sport-specific training, this also takes practice (and a lot of experimentation to find out what works) but you have to train your gut to be able to digest while exercising. Since those caloric requirements can be kind of high, I almost always recommend using a mix of sports drinks and solids to hit the requirements. Since you generally want to chase solids with water, this requires having some sort of hydration plan that allows you to carry both sports-drinks and water. Lastly, you don't want to take down all your calories at once, but rather, break up your consumption over the course of an hour. Most athletes either eat/drink every 15 minutes or every 30 minutes, depending upon preference for size of intake (the latter obviously mandates a greater intake per time you eat/drink). Finally, waiting for that 70-90 minute mark to "start" this process is *not* what this means. If you know you will be training longer, then start your in-workout fueling immediately. So, for a simple example, in a 100 minute workout, I will start fueling 15 minutes in, and by the end of those 100 minutes, have probably consumed around 600 calories.

- 30 minutes after a workout: Your muscles are starving for fuel (even if you did everything above right, you can only replace about half of what you burn) and this is the time to give it to them. So many athletes don't eat after workouts, and it makes no sense. Refuel in this period with a mix of simple carbs (again, muscles are hungry, don't make them wait, keep it simple) and proteins. The ideal combo is 4 grams of carbs for 1 gram of protein. This is why Chocolate milk gets so much hype, as it is nature's (with some tweaking by man) perfectly formulated recovery drink (4:1 ratio, mostly simple carbs thanks to the added sugars). If you have the $$ to spend, the specialized recovery products may be even better, because they don't include anything that you can't use right away, and thus focus on maximizing the value of every calorie to fulfill what your body needs following a workout. 300-500 calories for this snack is ideal, followed by a proper meal a few hours later. I don't want to go into too much detail, but force yourself to take in this snack immediately after a workout. It is so important for realizing the gains from the workout and recovering so you can be ready for the next one. This completes the "fueling" portion. Onto general nutrition.

2) General Nutrition

If you train regularly, you will notice that the act of "fueling" really requires you to take in a lot of simple carbohydrates. Here is where things get interesting: Simple carbs are really only good for one thing, fast energy. Otherwise, they really are not good for you at all. So, with that simple principle in mind, throughout the rest of the day, an athlete wants to focus on proteins, "good fats" (e.g., unsaturated, olive oil, fatty fishes, etc) and complex (brown rice, sweet potatoes, whole grain stuff) carbs that take a long time to breakdown and thus provide the body with sustained energy to get one through the non-training parts of the day. The exception to this rule is fruits, which are often high in sugars, but their benefit in anti-oxidants and other critical nutrients by far outweighs the "sugar" hit.

I am not going to touch on this in much more detail, since I am in no position to make caloric recommendations and don't want to dish out general daily nutrition advice since this is very personal. What I will do is leave you with a simple overview for general nutrition:

Get your simple carbs and splurge on your sugary cereals, granola bars, pop-tarts; just make sure that you time this splurge correctly and in the fueling "workout window." Once this window closes, stay away from simple carbs (outside of fruits) and the focus should shift to the other macro-nutrients (proteins, good fats) and complex carbs for sustained energy.

So, when you evaluate your overall nutrition as an athlete, think in terms of fueling and general nutrition. Go over what you currently do, and determine the things that need to change. Be patient, and remember, much like training the rest of the body, the gut needs training too. Start slow, and experiment with fueling techniques to see what works best for you. In terms of general nutrition, it may seem hard to stay away from simple carbohydrates, but once you get in the habit of doing this, it actually becomes quite easy, even in our modern day fast-food era.

I also want to stress that this is a broad overview and there is just too much on this topic to cover in any one blog post. Feel free to contact me for further questions, etc.

Tea and Endurance Sports

In a constantly changing "flavor the of the week" enviornment around nutritional performance enhancers, tea seems to withstand the test of time. Regardless of the magazine issue or dietary trend of the month, tea always works its way into the equation. For this week, I asked Randee Bloom (thanks for the guest contribution!!), an RN and tea collector/enthusiast why this is the case. Here is what she had to say:

Intense exercise or everyday normal function requires the replacement of vital nutrients and fluids. The careful selection of which dietary sources to consume and when is critical to restoration and performance. Endurance athletes are especially concerned with selecting foods and beverages that pack a punch by offering multiple benefits; such as both hydration and nutrients. Tea, the most consumed beverage in the world after water, may be a good choice.

All natural tea, including the white, green, and black varieties begins life from the same plant. It is the manufacturing process, including fermentation, which results in the different amounts of available nutrients. Because green tea is unfermented or not oxidized (the leaves are instead steamed) it does not undergo the process known to eliminate or severely reduce the naturally occurring polyphenols, including the most common and powerful, flavonoids. Compounds such as flavonoids have received considerable attention by healthcare providers and researchers as potentially offering anti-carcinogenic, anti-diabetic, anti-fungal, and even anti-viral properties. Research around the globe on animals and humans has and continues to be conducted to isolate specific benefits.

Focusing upon endurance exercise, no conclusive benefits have been reported:One research study tested green tea’s potential to improve endurance during exercise. The controlled study measured the running times to exhaustion in mice. Findings reported in the American Journal of Physiology in 2006 revealed that those animals fed green tea extract (“GTE”) had higher running times to exhaustion and higher muscle glycogen contents as compared with the exercised but not GTE-fed group. That said, no such findings have been replicated in humans. In a study published in 2010 in the International Journal for Vitamin and Nutrition Research, multiple respiratory and circulatory measurements of nine endurance-trained men were taken before, during and after exercise. Those who consumed GTE did not demonstrate performance or energy metabolism improvement. Unfortunately, the sports-science community seems to be at a mouse roadblock, for the time being anyways.

Green tea’s affect on fat oxidation:
One area of green tea’s potential benefit to all individuals, including those highly trained and seeking maximal metabolic function, is fat oxidation. A study published in the American Journal of Clinical Nutrition in 2008 found that young healthy men who consumed the equivalent of 3 ½ cups of green tea prior to their cycling measured higher fat oxidation rates, a measurement of how fat is broken down. Researchers suggested that green tea creates higher concentrations of noradrenaline, thereby stimulating fat metabolism which in turn is transported to the muscle providing fuel during exercise. This could be particularly beneficial for longer-course endurance athletes, who often race distances that deplete carbohydrate stores and require burning fat as fuel. In non-race situations, green-tea could be a helpful tool in achieving a particular body composition, by stimulating the burning of fat before during training sessions. That said, take caution (and see articles of the week) when attempting what have become known as “starvation workouts,” which while thought to increase fat-burning, may have minimal benefit and could be detrimental to training and fitness progression.

Green tea’s nutritional benefits:Rather obvious but possibly overlooked, green tea offers certain benefits as a daily fluid because of what it does not contain. Compared with common beverages of choice, green tea has relatively low levels of caffeine (certainly markedly lower than coffee, black tea, and traditional cola soft drinks). As a natural plant-based food, green tea offers a significant combination of vitamins, including more Vitamin C than black or oolong varieties. And maybe most notably, green tea contains many necessary minerals and compounds known as antioxidants. Research has demonstrated that the antioxidants in green tea are powerful enough to slow the oxidative damage to cells, possibly blocking the oxidation of LDL (bad) cholesterol and increasing HDL (good) cholesterol and improving artery function. Studies have suggested green tea drinkers reduce their risk of stroke and coronary artery disease. However, the FDA has rejected manufactures’ requests to permit labeling the beverage as “heart-healthy.” Few harmful effects have been reported following green tea consumption in otherwise healthy adults. In addition to these more general health benefits, anti-oxidants found in green tea may have a powerful effect on reducing the byproducts (e.g., crap released in the body during intense training and recovery) of oxidative stress endurance athletes place on their bodies.

In summary, as a highly available, inexpensive, and delicious beverage, green tea appears to be a safe, even smart choice, for seeking hydration. Few cautions are offered for green tea drinkers, especially noting the relatively limited amount of caffeine compared with that usually measured in black tea. However, claims that actual physiological changes can be obtained which benefit either exercise endurance or overall cardiovascular, muscular, or hematological changes have yet to be documented. It appears that the complexity of this plant and the interactions of multifaceted human biological processes challenge the study of green tea’s potential. The isolation of either a single component or a recommended dosage for optimum health or performance remains hard to find. Further studies are sure to follow, but for the time being, it seems like Green Tea is likely to help, and not do harm; something many (more expensive and highly marketed) supplements can’t necessarily say.