Archive for February, 2009

Understanding Interval Training

February 19, 2009

Stephen Seiler has a nice description of what happens in your muscles when you undergo interval training. It really serves to illustrate the differing physiological responses that come about with different durations at any given intensity. It also serves as a reminder as to why you don’t want to go 110% all the time (hint: optimal stimulus for cardiac stroke volume improvement is not the same as that required for widespread capillary growth and oxidative enzyme upgregulation.)

One interesting take on the article, if you look at the data he presents, is that you can have your cake and eat it too, if you exercise strict discipline. If interval duration is kept short enough, you can accumulate many minutes of time at faster than race-pace velocities while keeping the concentration of lactic acid in your muscles about what it would be at a more moderate, steady-state pace. The advantage of introducing that sort of training is that you work on neuromuscular efficiency as well as increasing oxidative capacity of type IIa muscle fibers.

Notice from the data, however, that if you ‘overcook’ the interval duration by even 60 seconds, the lactate concentration can almost double. You cross from a zone where you are training your cells to upregulate pyruvate dehydrogenase, an enzyme that aids in speedy aerobic metabolism, to a no-man’s land where you neither optimally stimulate aerobic or anaerobic metabolic pathways.

Cycling (and cross-country skiing for that matter) are aerobic sports, so next time you work out, give some thought about your specific goals for the day. Are you trying to improve stroke volume? Then go flat out for 3 minute intervals that hurt like the dickens. Do you want to raise your velocity at LT, the number one determinant of endurance performance? Then remember the lessons from the Seiler article and give your muscles the conditions they need to adapt.

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Sick

February 11, 2009

I haven’t posted here in a while because I’ve been sick. Rather than encourage further fatigue from developing, I’m taking a short break from the bike and skis. That is easier said than done, since we know that mitochondrial enzymes seem to have a half life of about 7 days, so I am detraining. Alas, that’s better than the alternative, which is getting really sick.

5 Minute Barrier

February 8, 2009

Today marked my achievement of getting to the 5 minute barrier. The last minute hurt, and my legs were getting ready to shut down by the end. I’m thinking that I may do additional 5 minute reps at this power output until the duration starts to feel a little easier. It’s probably not realistic to expect one minute improvements every time I get on the bike.

It does feel great to set a goal and then meet it, even if it does represent a baby step towards my overall goal.

Getting to Five

Getting to Five

Power Training To Increase Performance

February 6, 2009

This paper, by researchers in Finland, examines the link between neuromuscular power and running economy. What’s interesting to note here is that runners improved 5k performances without a corresponding increase in VO2max. However, the neuromuscular improvements associated with power training made them more efficient runners at race paces, and thus faster overall.

It seems that any quality training program should include some emphasis on power development. This would be especially true for cycling, which requires a high loading of the vastus lateralis and the ability to maintain high power for long periods of time.

 

Paavolainen, Leena, Keijo Ha¨ kkinen, Ismo Ha¨ – 

ma¨ la¨ inen, Ari Nummela, and Heikki Rusko. Explosive- 

strength training improves 5-km running time by improving 

running economy and muscle power. J. Appl. Physiol. 86(5): 

1527 – 1533, 1999training, whereas the development of maximal O2 

uptake (V˙ O2 max) is not influenced as much (e.g., Refs. 

10, 16, 18, 22). These observations are mainly based on 

experiments in which heavy-resistance strength train- 

What makes this study interesting is that it deals with trained athletes whom presumably have already attained a fairly high VO2max as a result of prolonged training. It would be interesting to compare the training program used in the study with a control group that performed short intervals at slightly faster than race pace for comparison. If neuromuscular adaptations are most specific to both the force and frequency of movement, then it would stand to reason that intervals at slightly higher than race pace would be at least as effective, perhaps even more, at decreasing 5k times.

Lunch

February 5, 2009

Here’s a Paleo lunch. If you haven’t heard of Dr. Loren Cordain yet, you should definitely check out his work. He wrote both “The Paleo Diet” and “The Paleo Diet for Athletes.”

Prep time: about 120 seconds.

Paleo Lunch

Paleo Lunch


 

Ingredients:

1 Avocado, 1 Tomato, Smoked Salmon Trim.

Muscle Fiber Adaptation Varies Depending on Workload

February 5, 2009

This article goes more in depth regarding the adaptations you see in skeletal muscle with various workloads. Notice the principle of specificity at work.

Human skeletal muscle fiber type adaptability to various workloads

RS Staron, RS Hikida, FC Hagerman, GA Dudley and TF Murray

Muscle biopsy specimens were removed from the vastus lateralis muscles of three groups of human subjects: controls, weight lifters, and distance runners.

A Must Read

February 5, 2009

When possible, it’s always better to read the original paper rather than just the abstract. Here’s a link to a must read paper on endurance by JO Holloszy and EF Coyle. Taken by itself, it could provide fuel for the ‘more is better’ approach, but remember to take everything with a grain of salt. After all, we are people, not rats, and there’s more to life than the number of mitochondrial enzymes in your quadriceps.

Here’s the abstract

Regularly performed endurance exercise induces major adaptations in skeletal muscle. These include increases in the mitochondrial content and respiratory capacity of the muscle fibers. As a consequence of the increase in mitochondria, exercise of the same intensity results in a disturbance in homeostasis that is smaller in trained than in untrained muscles. The major metabolic consequences of the adaptations of muscle to endurance exercise are a slower utilization of muscle glycogen and blood glucose, a greater reliance on fat oxidation, and less lactate production during exercise of a given intensity. These adaptations play an important role in the large increase in the ability to perform prolonged strenuous exercise that occurs in response to endurance exercise training.

Why No Watts/kg?

February 5, 2009

Astute readers may ask why I haven’t set a target for watts/kg. It’s a good question, and an issue for which I have a healthy respect. One oft-heard statistic states that if you can maintain 7w/kg for 30 minutes, you can win the Tour de France. In theory.

I’ve witnessed first hand what can happen when an obsession with the weight side of the equation leads to unhealthy behaviors. Through my own and others’ trials, it’s easy to see that there is so much more to enjoying your sport than the number reported by a scale.  Focusing on weight also disregards much more important parameters, such as your actual metabolic fitness and how you feel. As such, I’m purposely leaving out any discussion of weight when measuring performance in this blog.

Having said that, I’m about 5’6″ and a solid mesomorph. My dad is a really good sprinter, and my strength is doing out of the saddle uphill efforts that last 2-4 minutes in a huge gear. I have no idea what I weigh, and I don’t really care at this point, because it doesn’t matter.

Interesting article by Kirk Willet

February 5, 2009

This article by Kirk Willet has been around for a few years, but still merits a read.

This result suggests that mitochondrial density adaptations can be achieved in a reasonably duration independent manner (Dudley et al., 1982).  The overall higher mitochondrial densities associated with the higher intensities outlines the potential need for mitochondrial uncoupling and the AMPK signaling, at least beyond the completely untrained state.

-Kirk Willet


Whole Fitness

February 5, 2009

I’ll confess right now — I was an endurance junkie. In fact, I probably still am — give me an opportunity to go skate ski hard or ride a bike for several hours, and there’s a good chance I’ll take it. However, nowadays it’s all for fun. If I’m not feeling up to it, I’ll take it easy — maybe stay inside, nap, go for a walk. The compulsion to get out there, day after day, and push to the limits, is pretty much gone.

That doesn’t mean I don’t have goals — to the contrary, I’m hoping to document my pursuit of an endurance goal on this very blog, but I’m hoping to show that it’s possible to attain one’s goals without the banging of one’s head against the ceiling day after day. The philosophy that resonates with me is that of Sir Roger Bannister, the first person to run a mile in under four minutes. He trained no longer than his lunchbreak during the week, yet still managed to break a world record. His philosophy was not to fatigue the body, but rather to train it with specific stimuli. It also shouldn’t be a surprise that during his training to break the record, Bannister was also going to med school.

You’ll hear similar thoughts echoed by proponents of Arthur Lydiard. The legendary coach from New Zealand was notorious for having runners who would run 100 mile weeks, but even he cautioned them with the adage, ‘train, don’t strain.’

If you spend any amount of time perusing the Net for fitness advice or training philosophies, you will undoubtedly encounter a whole lotta dogma. There are piles of it out there, so watch where you step. However, hidden in that dogma you can also discern patterns regarding what works and what doesn’t.

Folks who focus on distance cycling and triathlon will spend all day focusing on ways to convert all of their muscle fibers to the slow-twitch phenotype. For them, strength and power training are the bane of their existence due to mitochondrial dilution, whereby the cellular powerplants become diluted in a sea of MHC isoforms, cells that help produce strength but don’t contribute to aerobic metabolism. A lot of these folks also can ride a bike for five hours straight, climbing thousands of vertical feet, without getting tired. I know, because I used to be one of them. However, if you look around at any 24 hour type endurance event, you’ll see that the ability to sustain elevated aerobic metabolism for hours does not translate into favorable metabolic fitness. A lot of the competitors are, to borrow a term used by Athur Devany, ‘skinny fat,’ meaning they are carrying excess adipose (and inflammation) even though they seem slim. It doesn’t help that conventional sports nutrition advocates a steady stream of sugar to fuel these activities, driving up insulin and contributing to insulin resistance in the cells, which in turn drives fat storage.

In the other camp, you’ll find the High Intensity Training (HIT) folks, who swear that you can get by on a diet consisting solely of sprints two to three days a week. While they tend to have much more ‘desirable’ body composition, they’d have a hard time going the distance if all they did was sprint. Perhaps they’ll cite the HIT study done at McMaster University, in Canada, whereby untrained participants who only did sprints exhibited similar aerobic gains to participants who performed steady state activity. While that will work for the untrained, what happens when you apply the same principle to trained athletes?

What both camps have in common is that they show the principle of specificity in action. This just goes back to physiology 101. Organisms adapt to specific stimuli. The biochemical pathways that lead to fat storage, mitochondrial and vascular proliferation, and MHC development are still being studied, and they are complex, but you don’t have to have a degree in physiology to understand that you’ll get better at what you practice. As Malcolm Gladwell points out in his book ‘Outliers’, there are no shortcuts to success — you have to practice your activity. Applied to my particular goal, of maintaining 330 watts for half an hour, I need to practice for it regularly.

Where the nuance comes in is the importance of judiciously combining the endurance junkie’s ‘more practice is better’ mantra with the HIT proponent’s call for adequate rest between training sessions. And, since I have neither the means nor the desire to measure my waking cortisol, GH, or inflammation markers, the next best thing is just a simple question: how do I feel today? The more honestly you can answer that question, the better off you’ll be in the long run.