Aerobic Energy Contribution to Short and Middle Distance Running

Previously we’ve compiled evidence that high-intensity athletic efforts are significantly more aerobic than once thought. Such evidence reveals that high-intensity efforts as short as six seconds can become significantly aerobic, and single max. efforts lasting less than one minute can be predominantly aerobic (i.e. more than 50% of the ATP is supplied by the aerobic system). While the evidence demonstrates a significant, progressive shift towards greater aerobic contribution during interval repeats, it also reveals the crossover from dominant anaerobic to dominant aerobic energy production can occur within the first 30 seconds of intense activity (correcting the old misconception that aerobic energy dominance requires several minutes or more and/or sub-maximal intensity). Together, this body of evidence suggests that short-duration, high-intensity training can deliver tremendous aerobic and endurance benefits because the training itself can be highly aerobic.

Adding to the evidence, we highlight below two separate studies that evaluated energy system contribution to maximal effort running of various short and middle distances. Two separate research groups conducted these studies independently and arrived at remarkably similar results.

Spencer and Gastin (2001)

In 2001, Matt Spencer and Paul Gastin analyzed energy system contribution to single, maximal-effort 200, 400, 800, and 1500 meter runs (See “Energy System Contribution During 200- to 1500-m Running in Highly Trained Athletes” (PDF)). They used 20 highly trained males, all of whom had competed at state, national, and/or international competition, each of whom were specialists in one of the distances to be tested. Each specialist was tested in their specialty distance only. The tests were conducted on a treadmill, set at 1% gradient to simulate the supposed energy cost of outdoor running. Energy system contribution was determined by measuring expired gases from the breath of the tested subjects while they ran.

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Theories of Fatigue and Training Implications

A few posts ago, we summarized the history of lactate research and explained how thinking about lactate and fatigue has evolved. In short, lactate is no longer thought to be a cause of fatigue. But if lactate doesn’t cause fatigue, what does?

We found a thoughtful consolidation of theories in Steve Magness’s 2010 grad school research project. While his entire paper delves into the science of performance and fatigue for distance running, Steve has consolidated modern fatigue theories into a practical framework that appears to apply well for all endurance athletes. The framework identifies manifestations of fatigue and their potential causes as follows.

Theories of Fatigue

Steve’s framework holds that two main manifestations of fatigue are 1. reduced energy production and 2. reduced muscular force output. These manifestations are thought to be caused by one or more of the following:

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Renato Canova on Nervous System Training For Fast Endurance Performance

It’s not very often we hear endurance coaches talking about the neural component of developing speed for endurance events. That’s why this bit from famed Italian distance running coach Renato Canova jumped out at us. As he explains, endurance athletes who make the mistake of (always) training slow miss the opportunity to train the nervous system for faster performance (note: CAPS are his):

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Renato Canova on Strength Endurance and High-Intensity Circuits

Renato Canova is a famed Italian running coach who specializes in training mid-distance and long-distance runners. He is credited with helping world-class Italian and Kenyan runners achieve phenomenal success. After hearing about Canova during Jay Johnson’s podcast interview with Nike running coach Steve Magness, we sought to learn a bit more about Canova and his training methods.

One of the bits that caught our ear during the Johnson/Magness podcast was that Canova prescribes so-called circuit workouts to his runners (and apparently so does Magness). It sounded as though these workouts contain a mix of high-intensity running intervals and bodyweight exercises designed to simultaneously increase strength and stamina. As you can imagine, this piqued our interest.

After some cursory digging on the web, we discovered this paper on a Russian triathlon website that appears to be written by Canova. The paper, entitled “Development of Strength Endurance: The Key to Improvement in the Middle and Long Distance Events,” appears to explain some of Canova’s training methods and the thinking behind them. It is unclear when the document was written, but it appears it was written at least as recently as late 2004, maybe more recently.

The paper itself is a fascinating read and we won’t dissect the whole thing here. But we will share some of the highlights. [Read more...]

Energy Systems Contribution to Elite Kayak Racing

The Journal of Strength and Conditioning Research released this new study online today ahead of its print publication. “Energy System Contribution to Olympic Distances in Flat Water Kayaking (500 and 1,000 m) in Highly Trained Subjects” by Zouhal et. al. adds to the volume of evidence that short-duration, high-intensity athletic efforts require greater and earlier involvement of the aerobic system than previously characterized by commonly-accepted energy systems models.

In the study, seven elite male kayakers raced 500 m and 1,000 m on flat water under competition conditions. Here are the results:

  • The 500 m, where average total race time was 108 seconds, derived ~78% of its energy from the aerobic system and ~21% from the anaerobic system(s).
  • The 1,000 m, where average race time was 224 seconds, derived ~87% of its energy from the aerobic system and ~13% from the anaerobic system(s).
  • In both distances, the aerobic system reached the crossover point (i.e. provided more than 50% of the energy supplied) and continued to increase in dominance after approx. 30 seconds of race effort.
  • In both distances, by approximately 45-60 seconds of race effort, the aerobic system was responsible for ~90% or more of the energy supplied.

These findings are compatible with numerous similar studies in running, cyling, and swimming. Together, this body of evidence supports the notion that high-intensity training efforts can have great benefit for endurance athletes precisely because such efforts are highly (and mostly) aerobic at distances and durations much shorter than commonly understood.

Matt Fitzgerald: Reach Full Ironman Potential on 12 Hours A Week

“[M]any triathletes can race a faster Ironman by following a well-constructed 12-hours-a-week program than they could with a higher-volume approach,” says Matt Fitzgerald. He describes how it can be done in an article entitled, “Minimalist Ironman Training.” According to Fitzgerald:

You can prepare for a successful Ironman triathlon with a program that has an average training volume of only 12 hours per week and a briefly-maintained peak training volume of 16 hours.  And by “successful” I don’t mean finishing alive. I mean covering the distance as fast as your genetic potential allows.

Fitzgerald proceeds to identify and explain his five reasons why a minimal approach may be better than a higher-volume approach:

  1. Swimming performance is all about technique, not fitness
  2. The swim just isn’t that important
  3. Cycling fitness crosses over well to running
  4. High-intensity indoor cycling is time-efficient and effective
  5. A dozen century training rides won’t give you much more cycling endurance than two or three

A seasoned endurance athlete himself, Fitzgerald derives his recommendations from personal experience and the training examples of other elite athletes. Of course, there is also plenty of scientific evidence in support of his ideas, particularly fitness crossover, high-intensity intervals, and reduced training volume.

Despite the title of his article, Fitzgerald’s plan is not the most minimal we’ve ever seen. After all, it still calls for regular weekly long runs (we presume over an hour) and regular 3.5 hr bike rides, sometimes longer.  Some coaches and athletes have found that even these can be reduced or eliminated.

Still, it’s noteworthy to see another athlete/coach/writer embrace what many of you already know (and what Jessi Stensland echoed yesterday): volume might work well for some, but for many others there’s a better way.

Thanks to Brett of @Zentriathlon for the tip.

Jessi Stensland, Elite Endurance Athlete, On Better Ways to Train

Jessi Stensland is an elite endurance athlete who has experienced first-hand the beneficial effects of transitioning from a volume-oriented training program to one that prioritizes efficiency, strength, and speed through proper movement. In 2003, traditional volume-based training had broken her body to the point where she was forced to walk away from the professional triathlon circuit. The very next year, Jessi discovered a more effective way to train.

After reducing her training volume, focusing on quality and efficiency of movement, and incorporating high-intensity intervals and strength training, Jessi returned to triathlon better than ever. She calls 2004 a dream season, finishing top ten at U.S. Olympic trials and flat-out winning Half-Ironman Mexico. She has been racing fast and healthy ever since.

Jessi recently posted on her blog a story about her awakening and the new training strategies that brought her body back from the brink and helped her race faster and healthier than ever. Here’s an excerpt (emphasis ours):

I have learned so many things over the years.  I’ve gotten to experience first hand, with my own body, what many only get to read about in scientific studies.  One particular example comes to mind.  I was reminded of it after reading yet another twitter from a professional triathlete that mentioned: “It’s simple.  Train more and you’ll go faster.” This certainly has truth to it.  However, assuming he means swim/bike/run more miles and minutes, then one major drawback is: there’s no insurance policy against injuries, which can kill anyone’s season, including top pros who have their career and major $$ on the line. A few examples, all from this past season: Terenzo BozzonePaula FindlayMichael RaelertThe key here is, although volume works, it’s not the only, nor the most efficient, and in my opinion, not the best, way to go about it.

Another mentioned to me this summer, in preparation for a triathlon that included a 40-45 minute climb on the bike:  “You need to ride 2.5-3 hours consistently to prepare for that climb.”  Wait what?  Why wouldn’t I just do what it takes to ride 40 minutes faster and faster?  My power output over a 2.5-3+ hour ride would never train my body to generate the amount of force required to maximize my power potential over a 40-minute climb.  That’s like saying you could squat with 100lbs for 3 hours and that would prepare you to squat with 300lbs for 40 minutes. Really?  On the contrary, the opposite is what works quite well.  If you train to handle 10 x 300lb squats it makes 30 squats with only 100lbs easy.  Seems simple to me.

Jessi has incorporated the lessons she’s learned into a program she developed called MovementU. It’s a hands-on seminar that educates and offers training strategies to endurance athletes with an emphasis on movement, efficiency, strength, and recovery. These lessons and strategies can be extremely valuable for endurance athletes at all levels including those who already train with intensity- and strength-based protocols and those who have become slaves to volume that would like to find a better way. MovementU has dates scheduled in early 2012 in CA, AZ, and NJ and other dates/locations are being planned.

Do yourself a favor and check out Jessi’s story as well as MovementU.


Charles Poliquin on The Negative Effects of Volume-Based Endurance Training

Charles Poliquin recently posted an article on his website summarizing what he calls, “The (Many) Negatives of Aerobic Training.” Though he refers broadly to aerobic exercise, it seems that he is mostly referring to traditional, volume-based endurance training rather than high-intensity and strength-based protocols (which tend to be lower in volume). The article highlights some of the reasons why more and more endurance athletes are eschewing traditional LSD-based training in favor of lower volume, higher intensity and strength-based training.  Toward this end, Poliquin makes the following claims:

Claim 1: Raises Long-Term Cortisol and Accelerates Aging

Poliquin references the following study to contend that aerobic training causes chronically elevated cortisol levels:

Skoluda, N., Dettenborn, L., et al. Elevated Hair Cortisol Concentrations in Endurance Athletes.Psychoneuroendocrinology. September 2011. Published Ahead of Print. [Abstract]

This study measured long-term cortisol levels of more than 300 experienced endurance athletes and 70 active-but-not-endurance-trained controls.  This summary details the researchers findings, namely that the endurance athletes had higher long-term cortisol levels than the controls. Further, the study revealed that, among the experienced endurance athletes, higher weekly training volume appeared related to higher relative cortisol levels:

From Suppversity: Relative increase in hair cortisol levels of endurance runners in relation to average weekly training load in kilometers (Kirschbaum. 2011)

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Aerobic Contribution to High-Intensity Training, A Brief Recap of the Evidence

[Updated 3/24/12]

We received an inquiry today from a magazine writer seeking research that supports the idea that short, intense training may be more aerobic than once thought.  Based on our response to his inquiry, we wanted to consolidate the evidence in a single post.

There appear to be two categories of research that support this theory:

The first type of research shows that single max. efforts become dominantly aerobic far sooner than old models predict. This includes the following:

  • Figueiredo et. al. (2010) evaluated a single max. effort 200-meter freestyle sprint by elite swimmers. The aerobic system became dominant somewhere between 30-60 seconds and remained dominant for the rest of the sub-two-minute effort. [Abstract]
  • Gastin (2001) reviewed dozens of studies on aerobic/anaerobic contributions to single max. effort sprints. He conclude that widely-accepted energy systems models are outdated/flawed and the aerobic system becomes dominant far sooner than previously understood. Though the paper estimates the crossover to aerobic dominance occurs around 75 seconds, some studies show it occurs under 60 seconds. [PDF]
  • Spencer and Gastin (2001) and Duffield and Dawson (2003) evaluated single max effort runs at distances of 100m, 200m, 400m, 800m, 1500m, and 3000m.  Spencer and Gastin noted a crossover to aerobic dominance between 15 – 30 seconds for the 400, 800, and 1500 m runs. Duffield and Dawson measured the same crossover only slightly later, but well before 60 seconds.
  • Zouhal et. al. (2012) measured energy system contribution in elite flat water kayaking racing distances of 500 and 1,000 m. They found the aerobic system reached the crossover point (i.e. provided more than 50% of the energy supplied) and continued to increase in dominance after approx. 30 seconds of race effort. In both distances, by approximately 45-60 seconds of race effort, the aerobic system was responsible for ~90% or more of the energy supplied.

The second type of research demonstrates a progressive shift towards increasing aerobic contribution during repeated max. effort sprints. This type includes the following:

  • Gaitanos et. al. (1993) evaluated ten 6-second sprint repeats and found a progressive shift toward greater aerobic contribution. [PDF]
  • Putman et. al. (1995) evaluated three 30-second maximal sprints separated by four minutes rest. During the 1st sprint, aerobic contribution was 29%. By the third sprint, aerobic contribution was 63%. [PDF]
  • Bogdanis et. al. (1996) evaluated two 30-second maximal efforts separated by four minutes of passive rest. They found that the the aerobic system generated approximately 34% of the energy produced during the first 30-second sprint and increased to 49% for the second 30-second sprint. [PDF]
  • Trump et. al. (1996) evaluated three 30-second maximal efforts with four minutes rest between. They found that aerobic contribution during the first bout ranged from 16-28% and increased to ~70% in the third bout. [PDF]
  • Parolin et. al. (1999) evaluated  three intervals of 30-seconds maximal effort separated by four minutes of passive rest. Total average aerobic contribution was 34% for the first interval and 58% for the third. [PDF]

Together, this research establishes that short, intense training becomes predominantly aerobic very quickly and increasingly aerobic during high-intensity intervals.

Gaitanos et. al. (1993): 6 Second Max. Effort Sprints Go Aerobic!

OK, admittedly the title of this post sounds gimmicky. We should start by clarifying that we’re not suggesting endurance athletes go out and hammer training for just a few seconds at a time. But ever since we’ve started talking about revised energy systems thinking, we’ve repeatedly heard the same question: How short can the intervals be while still eliciting a significant aerobic response?

It appears just 6 seconds can do it.

In a 1993 study, Gaitanos et. al. set out to determine what percentage of energy was driven by each of the two anaerobic energy systems (phosphagenic and glycolytic) during ten 6-second all-out sprints. To do so, the researchers evaluated the relative energy contribution of PCr degradation and glycogenolysis. During the intervals, the researchers measured a substantial, progressive decline in anaerobic contribution marked by a massive drop-off from glycolysis. Researchers theorized that a significant migration to aerobic energy production occurred.

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