This article originated with discussions on why I am able to put together a decent Ironman race when everyone finishing around me can absolutely crush me over shorter distances. It’s also been heavily influenced by the philosophy of my coaches (Hellemans, Molina and Friel), my athlete buddies (mainly the Swedes Doodes) and articles/books that I’ve read.

Probably the best article that I have read on successful training is a simple piece that covered Mark Allen’s advice for lifetime fitness (Outside Magazine, February 1998, p 41-50). There is a lot of good advice in there and I recommend it for any athlete.

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In this article, I am going to give you my opinion on what really matters for endurance success.

In reading many of the publications and surfing the internet, I can see that there is a lot of interest in high intensity training. My experience with coaching and my own racing has led me to believe that excessive high intensity training fails to address what limits working athletes and impairs the development of endurance athletes.

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Let’s start with a review of the Four Pillars of Endurance Success:

• Nutrition – You will find our best advice on this in the Nutrition section of the library. If you remember one thing — EAT REAL FOOD
• Strength – Also covered in its own section. Strength training enhances your metabolic rate, economy and muscular endurance. It’s also a key limiter for many novice, female and veteran athletes.
• Economy – The energy cost of holding any given speed. Economy is enhanced, to a greater and lesser degree, by just about any form of training (so long as you hold good form). There are many ways to improve economy and I’ll discuss my views on why economy is important.
• Aerobic Threshold Endurance – a critical success factor for endurance performance and the main topic of this series.

I was reading an article written by a buddy of mine about his recent experience training with a group of pros. Like me, his first impression when training with elites was how fast they go. The next time you are watching a race or training with elites, try to avoid getting caught up in the speed. Simply watch them move. I have watched a lot of athletes move over my athletic career. If you do this then you can very quickly spot the real players.

I want you to notice three things – comfort, relaxation and smoothness. The thing that truly amazes me when I watch an athlete like Craig Alexander race, is not “how fast he goes,” it’s “how smooth and relaxed he is when going fast.” Crowie doesn’t look like he is going very fast but he’s really moving. That kind of speed comes from a very deep form of fitness and superior economy.

What is Aerobic Threshold?
There are many different ways to determine training intensity zones (lactate testing – see Hellemans, best average time trial average heart rate and/or power – see Friel).

Personally, I think the easiest and most effective method is to apply subjective perception. Start training at an easy pace and slowly increase the intensity of your exercises. You can determine your aerobic threshold by noting the heart rate where you feel the first deepening of your breath.

The point of deepening is the bottom range of your aerobic zone. The top of your aerobic zone can be estimated by simply adding 10 beats per minute to the bottom figure. I’ve done a lot of testing over the years and this method seems to work just fine for endurance training.

Why Aerobic Threshold?
When I first started training for triathlons my goal was to constantly drive my functional threshold pace upwards. I figured that if my top end speed increased then my race times would fall. This is what I call a top down approach to fitness. It is what the majority of athletes believe will lead to success. We’ve all heard the phrase, “train slow, race slow”. My view is that a top down approach neglects the two most critical elements of successful long course triathlon racing.

• Endurance – it doesn’t matter who you are, you will not be able to maintain high intensity for an entire long course event (although that doesn’t stop us from trying from time to time).
• Race pace – most athletes race long in their aerobic zone or LOWER.

Take these two points together and, my view, is that the key variables to optimize are aerobic threshold endurance (first); and then aerobic threshold pace (second).

Let me illustrate with an example of two athletes. Let’s assume that the first athlete is me and the second athlete is a mid pack IM finisher (call him “Buddy”). For long course performance, what are the key physiological differences between Buddy and me?

Aerobic threshold endurance – I will last longer and travel faster at aerobic threshold. When I was an Ultrarunner, I could last 12 hours at aerobic threshold. Buddy’s been endurance training for a while – let’s say that he lasts seven hours at aerobic threshold. Frankly, I think that seven is generous – as we all know – a one-hour open water swim followed by a six-hour aerobic ride is one tough session. For the average IM athlete, my estimate is that we are looking at aerobic endurance in the six to ten hour range.

Body composition — Buddy is bigger than me. This reduces his economy and slows him down at all levels of intensity.

The key challenge facing Buddy is how to extend his aerobic threshold endurance beyond his estimated race duration but, there is a catch. No matter how fit Buddy gets, he’s going to have a tough time taking his aerobic endurance much beyond 10 to 12 hours (remember that the average finishing time at most Ironman races is over 13 hours). This is where body composition comes into play because our economy/pace per watt/heart beat/RPE are all enhanced from improved body composition. Add the recovery/long term health benefits and nutrition becomes even more mission critical for the athletes in the back half of the field.

Implications and ideas for you:

• Novices should spend nearly all their time enhancing economy and building aerobic threshold endurance.
• Experienced athletes with race times that are significantly longer than their aerobic threshold endurance must address their body composition. For the back half of the field, this is the most rapid way to achieve significant gains in economy, and therefore, aerobic threshold pace.
• If your aerobic threshold endurance is equal to or less than your anticipated race duration then spending ANY time above aerobic threshold in a race will prove costly. Eventually, you will find that you are unable to get your heart rate up. You will have simply taken yourself beyond your aerobic threshold endurance. With my own racing, this happens in the 10- to 11-hour range. This seems to be an explanation for why many well-nourished and well-hydrated athletes simply run out of gas. I think this is the most common form of “bonking” and it has nothing to do with race nutrition or hydration.

Practical Application
So how best to apply the Four Pillars? I would recommend the following tips for building your week:

• Strength train.
• Schedule at least three sessions of each sport – if you stick to training in your aerobic zone then elite and experienced athletes can tolerate four to six sessions per sport per week.
• Gradually push your endurance envelope while improving your sport specific skills/economy.
• As you get faster, train longer and more frequently rather than more intensely.

Remember that getting tired is the point of training. Fatigue yourself with aerobic training. Once you are tired use total rest (best for novices) and active recovery/skills work (best for elites and experienced athletes) for restoration purposes.

You need to be quite fit to handle a lot of aerobic volume. It sounds easy but heading out and riding a focused six hours in your aerobic zone is one heck of a tough session. Many athletes will need to start with primarily easy pace and moderate amounts of aerobic work inserted into their endurance sessions.

A Word on Swimming
Here are some key points to remember with your training.

Most of us don’t wear heart rate monitors in the pool. So how can you estimate your aerobic zone? Based on my experience, it is likely to be the pace that is about seven seconds slower per 100 meters than your 1,000-meters best average time trial pace. This should be a comfortable bilateral (three stroke breathing) pace. If you cannot hold this pace swimming bilaterally then you would be best to work on swimming technique rather than swimming aerobic endurance.

As a reminder, the short intervals and high-intensity work that many swim coaches (and athletes) prefer is sub-optimal for developing your aerobic endurance. I have made my greatest gains in swimming from focusing on threshold and sub-threshold endurance and strength work. Moderate amounts of faster work are beneficial for strong swimmers, but you rarely want to be generating very high levels of lactate.

For those of you who swim 1,000 meters slower than 17:30 – keep the pace down. Why? Because technique is near impossible to hold under high intensity levels (be honest with yourself!). Absolutely perfect swimming in your aerobic zone is best.

What about my speed?
I can hear many of you wondering, “how am I going to get fast if I only tool around in my aerobic zone”? My athletes express this all the time during the winter and spring. I hate to break it to you but we aren’t fast. Crowie and Chrissie are fast, you and me, we simply aren’t that quick.

Have a look at the finishing times for the people at the top of your age group or even the pros. Running a seven-minute mile is not fast (to a runner), running 26.2 (or 13.1) of them after a swim and bike – that’s solid and is what we are seeking to build. If we sacrifice our aerobic training then we are fooling ourselves. Solid endurance performance is about not slowing down – in order to achieve this goal we need to be aerobically fit, economical and strong.

While “speedwork” (anaerobic endurance sessions) is not recommended, I strongly recommend that you do quickness training. These sessions include strides, spin-ups and other technique drills that will build quickness/economy while not generating high levels of fatigue (See my book, Going Long).

Summary
But I’m going so slow…

When you start training this way, you are going to be moving very slowly. I’m a reasonable runner and my aerobic pace starts each season very slow. I would encourage you to keep the faith with your swim, bike and run sessions. If you stick with it then your aerobic endurance and aerobic pace will increase. Remember that you are training for a very long day of aerobic exercise.

As your dedication pays off and you start to see the results, you will have the urge to test yourself. My recommendation is that you test your endurance, not your speed. Aim for the following goal sessions:

• Swim – One and a quarter hours, long course (50-meter pool), continuous aerobic swimming with three stroke breathing
• Bike – Six hours, continuous aerobic riding
• Run – Two and a half hours, continuous aerobic running

The EC program here builds you (safely) towards these goals. Again, these sessions may sound easy (for the experienced) but the focus and fitness required to hold your aerobic zone for an extended period of time will surprise you.