Monday, March 22, 2010

Physiological Fitness - Economy

It's been a long time since I lasted posted anything here. Putting on a camp in Majorca wih all of the travel and time zone changes has made things a bit challenging this past few days. And then a flu bug on top of all of that really did me in. But I'm much better today and managed to find time between camp activities to do some writing.

The last of the big three physiological fitness determiners is economy. Sport science understands less about this one than the other two, but it may be the most important. It has to do with how efficiently you use oxygen while exercising. Measuring oxygen used is just another way of measuring energy during exercise since in the human body how much oxygen you use also tells you how much energy you’re expending. Your economy is much like the economy rating for a car. – how many miles per gallon of gas. Only in the case of exercise it’s how many milliliters of oxygen per mile.

The longer the race is the less important aerobic capacity becomes and the more important economy is. This is because at the longer distances you exercise at a lower percentage of your aerobic capacity. So having a big VO2max won’t be of great benefit. But wasting even a little energy per stroke or stride due to poor economy will add up to a lot of wasted energy – and a slow performance – in a long race.

We know what can be done to boost your aerobic capacity. You can do lots of miles and mix in high-intensity intervals. Economy is a bit different. There are some things you have control over, but many you can do nothing about. For example, we know that for swimming being tall with long arms and legs and big feet improves economy. Unfortunately, you can’t change those. In the same way, for cycling having a long femur bone relative to your total leg length improves economy. For running being short and small are good for your economy. As an endurance athlete economy is improved by having a greater percentage of slow twitch muscle fibers. And there are other improvements to our physiology we would also make if we had control over them such as increasing the number of mitochondria we have (these are the little powerhouses in the muscle cell that produce energy). These are all things we have little or no control over.

So what things can you control to improve your racing efficiency and use fewer milliliters of oxygen per mile? The most common technique. You must realize that if you decide to go this route and make changes to your current technique that there will be a period of time during which you become less efficient. This will show up as a higher than normal heart rate at any given speed or power. And it may take weeks if not months to make the new technique your normal. At that point you should be faster at the same heart rates as before.

Others that are beneficial for the bike and run are reducing excess body weight and using lighter equipment. Then there are sport-specific efficiency improvers. The most notable is aerobars on the TT or tri bike along with other aerodynamic equipment such as wheels, helmet and bike frame. As a swimmer you can improve economy by improving the flexibility of your shoulders and feet, especially the ability to point your toes. Interestingly, the research shows that having less flexibility in the ankle joint makes for more economical running as this appears to improve the release of energy stored in your calf muscle with each footstrike.

Training components that improve economy are intensity and frequency. Training at a high speed or power has been shown to make athletes more economical at all speed and power outputs including the lower range. But it doesn’t work both ways. Going very slowly doesn’t pay off with greater economy at the high end of speed and power.

One of the best ways to improve your technique and therefore your efficiency is to do your sport frequently even if each session is very brief. For example, for a triathlete to become a more efficient swimmer with only two hours a week to devote to it, swim four times a week for 30 minutes each time. That will improve your efficiency sooner than doing two, one-hour swims each week.

Plyometric exercises have also been shown to improve economy in both runners and cyclists. This involves doing explosive jumping, bounding and hopping drills. For the run brief, powerful hill repeats are much like plyometrics.

There is still a great deal of debate about whether or not traditional strength training with weights improves economy. I believe it does as I have seen so many of the athletes I’ve coached over the years improve their performances remarkably after a winter of lifting weights – provided they did exercises which closely mimic the movements of the sport. Doing curls is unlikely to make you a better runner. But doing step ups may help.

In summarizing the three physiological fitness determiners remember that aerobic capacity is largely the result of your genetics as optimized by steady training over many years. And the longer your race is the less significant this is to performance, even though it wouldn’t hurt to have a high VO2max. Lactate threshold is highly trainable and you should see a steady improvement in your speed or power when you reach this threshold. Economy may be the best determiner of performance of the three. But, as mentioned, we don’t know a whole lot about it and much of what is known to be important is out of your control. The things you do have some measure of control over often take a long time to accomplish (e.g., changing your technique), are difficult to achieve (e.g., lower body weight) or are expensive (e.g., lighter bike).

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Sunday, March 14, 2010

Physiological Fitness - Lactate Threshold

I apologize for the recent gap in posts. I'm preparing to go to Majorca for a camp next week and so have been up to my ears in work that needed to be done first. This post is a continution of the topic I started last week - the three determiners of physiological fitness. The last post discussed aerobic capacity. This one has to do with lactate threshold.

While aerobic capacity gets a lot of ink in endurance-sport magazines, for the competitive athlete the lactate threshold is what the bulk of the hard training should focus on. Your aerobic capacity isn’t going change a lot if you’ve been training and racing seriously for three or more years. But you may be able to bump your lactate threshold up a lot.

So what is lactate threshold? We need to start with a little biochemistry to understand this measure of intensity.

As your body uses carbohydrate to create energy it creates a by-product inside the working muscle cells called lactic acid. As the intensity of a workout increases this liquid begins to seep out of the muscle cell into the surrounding space and blood stream. In so doing it changes its composition by giving off hydrogen ions. It’s now called lactate. Despite its “bad boy” reputation, lactate is actually a beneficial substance for the body during exercise as it is used to create more energy so that exercise may continue. It’s the hydrogen that is the real bogey man. This is what causes the burning sensation in your muscles and the heavy breathing at high effort levels. Measuring lactate levels in the blood is a convenient way of estimating how much hydrogen is in the body. The more intense the workout, the greater the amount of lactate released into the blood — and the more hydrogen ions interfering with muscle contractions. (By the way, neither lactate or hydrogen ions cause the muscle soreness you may experience the day after a hard workout. That's another of the myths that refuses to die in sport. Some day I will do a post just on such old saws.)

Lactate threshold is sometimes referred to as anaerobic threshold. While sports scientists may argue about the differences between these two terms, for athletes there is little reason for concern. Both are essentially the high intensity at which you begin to “red line.” On a perceived exertion scale of 1 (low) to 10 (high) you redline at about 7 or 8. Whatever your heart rate, power or pace is at this moment is your lactate threshold intensity. The higher this is as a percentage of your aerobic capacity the faster you will race, especially in steady-state events such as triathlons or endurance running races. It’s common with fit athletes for their lactate thresholds to fall in the range of 80 to 85 percent of their aerobic capacities.

Most well-conditioned athletes can sustain this level of intensity for about an hour. Because of this there is a new term created by Hunter Allen and Dr. Andrew Coggan, the authors of Training and Racing With a Power Meter, to describe this intensity – functional threshold. This is the average bike power (functional threshold power – FTPw) or running pace (functional threshold pace – FTPa) you can maintain for one hour. Simple.

If you are using heart rate to determine your training zones, your lactate threshold heart rate (LTHR) is your average heart rate for a one-hour race effort. This is unique to the sport, so your rowing, cross-country skiing, swimming, cycling and running LTHRs are likely to be different. And therefore your heart rate zones will also be unique to each sport.

The body has two ways of improving your lactate threshold as a result of training. It can come to better tolerate the acid and it can also become more effective at removing the acid. As with all aspects of fitness, the way to train your body to tolerate and remove hydrogen ions is by training at your lactate threshold. This, then, is the best marker of training intensity. That’s why I base heart rate zones on it rather than on maximum heart rate.

I hope to get something posted on the last topic - economy - soon but expect this may be at least a week or more. We'll see.

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Sunday, March 7, 2010

Physiological Fitness - Aerobic Capacity

Exercise physiologists generally agree that there are only three things you can improve to become physiologically more fit for endurance sports performance: aerobic capacity, lactate threshold and economy. Ultimately, these are the reasons you train. So what are they and how do you improve them? I'll discuss aerobic capacity now and come back to lactate threshold and economy in a few days.

Also referred to as VO2 max, aerobic capacity is your ability to use oxygen to produce energy. The more oxygen your body can process the more energy you can produce and the greater your output (power or pace). It’s common to find that the fastest athletes in a race have the highest aerobic capacities of the entrants. The farther down the race results you go typically the lower the athletes’ aerobic capacities. But don’t take this to mean that knowing your VO2 max tells you how fast you will go or how well you will do compared with others in your race category. The two other physiological factors – lactate threshold and economy – also play a major role in race outcomes. One of these by itself does not constitute all of what it takes to race fast.

Aerobic capacity is literally at the heart of success in endurance sport. Improvements in aerobic capacity have largely to do with how much blood (which contains oxygen) the heart pumps out to the working muscles with every beat. This is called “stroke volume” and has a lot to do with how much aerobic capacity you have. A purpose of training is to improve your stroke volume. There are basically two ways to do this. The first is to focus on the volume of your training. The heart responds to lots of time spent at higher-than-resting intensity (above about 50 percent of VO2 max) by becoming more efficient and effective which ultimately means pumping more blood per beat.

The other way to improve aerobic capacity is by doing high-intensity intervals, especially those done at about the power or pace associated with your VO2 max. At that intensity your heart rate is approaching maximum, so these are very hard efforts. This method will produce a higher stroke volume sooner than by relying only on volume. Most experienced athletes employ both strategies.

There are other physiological contributors to aerobic capacity such as aerobic enzymes found in the muscles, blood vessel diameter and ability to dilate, blood volume and related hematocrit (red blood cells). Many athletes seem to believe their lungs are the deciding factor when it comes to aerobic capacity. Training produces insignificant changes in lung volume.

Body weight also has a lot to do with aerobic capacity. The formula for determining VO2 max is expressed in terms of milliliters of oxygen consumed per kilogram of body weight per minute. What this means is that as you lose body weight, especially fat as opposed to sport-specific muscle, your VO2 max increases. And most of us have experienced this at both ends of the weight spectrum. When we have gained weight it’s harder to run or ride a bike uphill. Conversely, when body weight has been low the effort of exercise is decreased at any given power or pace. This is clearly the affect of body weight on aerobic capacity.

Aerobic capacity is largely dependent on who your parents were. Research (Bouchard, 1986) has shown that identical twins have nearly identical aerobic capacities. While genetics probably sets the boundaries for the upper limit of your VO2 max, proper training can take you to near the upper limit. But also bear in mind that there are two other physiological factors that contribute to endurance performance. I'll come back to them soon (I hope).

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Tuesday, March 2, 2010

Core Strength

About a year ago I posted a blog on this same topic. It's a topic I have given lots of thought to recently and so decided to return to it again. I'm still learning what the impact of poor core strength on cycling and swimming may be and so would appreciate any insights from readers.

We read a lot about core strength training any more, but I’ve found most people really don’t know what it means. Most seem to think it means strong stomach muscles. It goes well beyond that. Core strength could be called “torso” strength. It has to do with small and big muscles from your armpits to your groin. These core muscles stabilize the spine, support the shoulders and hips, drive the arms and legs and transfer force between the arms and legs. It’s very much akin to the foundation of a house.

When a triathlete has poor core strength it may show up in several ways. It’s most obvious in running. Poor core strength is evident in a dropping hip on the side of the recovery leg with the support-leg knee collapsing inward regardless of what the foot may be doing. Especially in running, injury is common when core strength is inadequate.

In the two sets of screen shots here you can see two athletes on treadmills running barefoot (click to expand the pictures). Notice first of all the waistline of the shorts of each runner. It indicates what the hips are doing. You’ll see that the woman’s left hip is dropping quite a bit while the man’s stays quite level to running surface. Also note the woman’s slightly collapsing right knee. The man’s is very stable. But the big surprise is their right feet. The woman’s foot has very little pronation and would be considered a stable foot. The man’s is excessively pronated (see the third screen shot).

This is backwards from what we have always been taught to believe about the foot and what happens up the chain. Excessive pronation is supposed to cause unstable knees and hips. Stable feet should not result in hip drop and medial knee wobble. The difference is core strength. The woman’s is poor and so even her feet can’t help. The man’s core is strong and overcomes a foot that would normally cause all sorts of injury problems. And in this case the man is known to have no history of injuries and is an accomplished marathoner. The woman, despite her excellent foot stability, has experienced illiotibial band injuries. Core strength is the difference. The man has it; the woman doesn’t.

For swimming and cycling it is less obvious. Poor core strength in swimming may result in “fishtailing” – the legs and hips wiggle from to side as the hand and arm “catch” is made. Sometimes this is due to faulty stroke mechanics, so it’s hard to differentiate. But poor stroke mechanics may even result from poor core strength in thi case.

In cycling poor core strength can show up as a side-to-side rocking of the shoulders and spine when the pedal is pushed down, even when the saddle is the right height and the rider is not excessively mashing the pedals. This is generally most evident when climbing seated.

There is little doubt, even if it’s not always obvious, that poor core strength results in a loss of power in all three sports.

How do you know if your core strength is adequate? One way is to have a physical therapist do a physical assessment. Find one who works with endurance athletes and tell him or her that you would like a head-to-toe exam to pinpoint weaknesses and imbalances that could reduce performance or lead to injury. And also find out what is recommended to correct any problems found. These fixes may be strengthening exercises, flexibility exercises or postural improvement. This is perhaps the best way of finding out, but there is a cost. The exam generally takes about an hour. I have each of the athletes I coach do this every winter. It’s provides a great start on core strength training.

While quite a bit less effective, another way is to have someone video tape you while running looking for the dropping recovery-side hip shown above. You’re likely to miss the details as for the untrained eye there appears to be little difference in techniques even when the movement faults are gross. Use a treadmill and shoot the video from the back. Tuck your shirt in so you can watch the waistband of your running shorts on the video to see if it dips when the recovery leg swings through. And check the knee of the support leg to see if it is buckling in slightly. You will probably have to view this in slow motion several times to see the unwanted movements if there are any.

If you go the self-help route and determine that you need to improve core strength I’d recommend picking up Core Performance Endurance by Mark Verstegen. This is one of the best books I’ve found on core strength training for endurance athletes.

Special thanks to Mark Saunders, physiotherapist and Director of Physio4Life in Putney, UK, for the pictures and introduction to this concept.


Thursday, February 25, 2010

Easy Means Easy

Sometimes the hardest part of training is going easy. I'm reminded of this from riding with two of my clients who were in town on Tuesday. Both they and I had recovery rides scheduled as we all had hard workouts planned for the following day. I could tell they were having a hard time 'going for a walk' on a bike. At one point I had to chase one of them down to get the effort low again. When we were done one of them told me he had never had such a low heart rate on a bike ride.

Since they are both now starting their Build period, their training must be either hard or easy - never in between. 'Hard,' of course, is related to the event for which one is training. It doesn't mean maximum effort all the time. 'Easy' means zone 1. If one makes the easy days easy, the hard days can be hard. And race fitness improves. If, on the other hand, easy becomes moderate then hard also becomes moderate. And there is little progress.

I learned this lesson from Gary Muhrcke, the winner of the first New York City Marathon in 1970. In 1982 Gary and I both owned running stores (I believe he stills owns his - Super Runner in NYC; I sold mine - Foot of the Rockies - in 1987). That year Tiger running shoes (now called ASICS) had a national sales promotion. The top-10, best-selling stores of their products would win a one-week, all-expenses-paid vacations for two to the Bahamas. Gary's and my store were winners. We met the first day and decided to run together every morning. The next day we met to run. After a few minutes we were running a much faster pace than I was ready for. I felt like I was in a race. I dreaded the next morning. But that day he took us out at such an easy pace that it was embarrassing. It must have been a 9-minute pace. Then the third morning it was a race again. And it went on like that the rest of the week. At the end of the week I was in much better shape, I could tell.

That's when I learned about hard-easy and I've been doing it ever since. It works. But most athletes don't give it a chance. When they feel their fitness is slipping the first decision they make is to increase the intensity of their easy days. It should be just the opposite - make the easy days easier. That will ensure you are ready to go for the next hard workout. Give it a try.

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Tuesday, February 23, 2010

Answers for an 8th grade student

Last week I received a letter from an 8th grade student in Los Angeles who had some questions about triathlon. With all of the talk about childhood obesity and too much time in front of electronic media it's great too see an interest in something as healthy as triathlon. The following is my reply.

Thanks for your recent letter, Camille. You asked some very good questions. Here are my answers.
Q: Which segment is the hardest, swimming, cycling, or running?

A: It depends on who the athlete is. Whichever event one is weakest at is usually considered the hardest. If the athlete is equally strong in each sport then it often comes down to the one in which he or she believes offers the most opportunity for a good overall race performance. So they may work harder in this leg of the race to gain an advantage. That is often the bike since it makes up about half of a triathlon. But many other triathletes would say that the run is the hardest even if they are good runners simply because there is a lot of accumulated fatigue by the time it starts. So there really is no consensus on which is the hardest.

Q: When did you first become interested in triathlons, and why?

A: In 1983 I had surgery for an ankle I had sprained many times while running. Since I couldn’t run for a few weeks I started riding my bike. I had done this often when injured in the past and had become a fairly good cyclist. A couple of weeks or so after the surgery I was riding my bike in the mountains outside my home in Colorado when I crashed. I injured a shoulder pretty badly. My doctor suggested that swimming would help it to rehabilitate. A couple of weeks later I was swimming and it occurred to me that I was swimming, cycling and running, and I was aware of this new sport called “triathlon.” So I decided to enter one. I was hooked. Once again I found that the worst things often turn out to be the best.

Q: What helps you get your energy up when you are at a rough part of the race?

A: There are two things that you get you through the “hard patches.” The first is training. To do well in triathlon, as in any sport, you have to train for the hardest portions of the race. These often occur in the latter stages of the race when fatigue is setting in. Training should prepare you to minimize the feelings of fatigue. The second part of the answer has to do with mental preparation. We don’t always have races where everything goes to plan and we feel great all the way. In fact, that is rare even when we are well-trained. In such situations the athlete must be mentally prepared. Essentially, that means he or she has developed the mental strength to keep moving forward even if it isn’t their best effort. Something that helps with continuing ahead is knowing that these bad patches don’t always last the remainder of the race. They usually come and go as the race progresses. So at the end of the current bad patch there will be a good one. Be patient and things will get better.

Q: What inspired you to get into triathlons?

A: As far back as I can remember in grade school I was interested in sport. I have always loved the challenges of competition. Later in life I learned that competition is about becoming the best person you can be. I also learned that my competitors are the ones who do the most to make me a better person. I am competing with them, not against them. Without their efforts there would be no satisfaction and little gained in sport.

Q: What is your favorite part of triathlons?

A: This probably isn’t what you were getting at, but my favorite part is seeing the athletes I coach achieve – and even exceed – their performance goals. Having helped someone accomplish something that only a few weeks before was little more than a dream is very rewarding.

Q: What was the best race that you have ever done, and why?

A: I have had many races where first place in my category came down to me and one other athlete with whom I was racing shoulder-to-shoulder. There have been a half dozen or so of these for me. Some I won. Some I lost. But in either case the competition was intense and the lasting memory vivid. Races in which I have won my category easily are soon forgotten. And those in which I was not a contender faded quickly from memory. But for those that were tight and I was at my limit I can recall every detail of the experience. It’s remarkable how clear the memory is of such races.

You said that your mother and you had an interest in triathlon but you didn’t mention if you are both doing them. If not, I hope you decide to take the plunge. It’s a great sport with a lot to offer for people of all ages and abilities. If you do, please let me know. I hope to see you at a race one day.

Joe Friel

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Sunday, February 14, 2010

Specificity of Training

I consider specificity the most important principle of training. And I tie specificity in with periodization to create training plans for the athletes I coach. So what is it? Basically, the specificity principle says that if you want to become good at something you need to do that thing. Sounds pretty simple, huh?

According to the specificity principle to ultimately become good at bicycle racing you should ride a bike – not run. That seems fairly obvious, but it’s remarkable how many cyclists, when short of time, will resort to a run workout. That may be ok early in the Base period. But in the Build period (3-11 weeks before the A race) there is very limited value.

So how about this one… If your goal is to run a 7-minute pace you need to do a lot of 7-minute-paced running. Not 8 minutes and not 6 minutes. There is this thing called “economy” which relates to the principle of specificity. If you spend a lot of time running 6- or 8-minute pace you will not be as economical at 7 minutes as you could have otherwise been. Economy has to do with how much energy you use (or waste) at a given pace.

One I deal with a lot has to do with triathletes and bike races… Many multisport athletes believe that bike road racing is good training for triathlon. It’s not. Bike races are, indeed, aerobic events, as are triathlons. But that’s where the similarity ends. The outcomes of bike races are determined by two-minute episodes when all hell breaks loose. They are anything but steady state aerobic. Bike racing has a huge anaerobic component which is critical to success. No one in their right mind races a triathlon that way. Triathlons are steady and anaerobic intensity is avoided. A bike race done by a triathlete is largely a wasted workout day. It’s even worse than that because the recovery after one of these delays when the next, truly specific triathlon workout can be done.

(A brief aside… I know many triathletes may be upset about what I just said. I’m sure I will get comments about pros who do this and how successful they are. But I think they’d be better if they stayed focused on triathlon. Some will comment on the “fun” factor of doing bike races. I have no problem with that. I used to do that myself and coach athletes who also participate in both sports. Everyone needs to decide what it is they want from sport. In other words, what is “fun” for you? You can be a generalist who is pretty good at a lot of different things, or you can be a specialist who is very good at one thing. I have no qualms about either. Either can be "fun." The purpose of this post, however, is to describe how to be very good at one sport. Now back to specificity.)

Here’s an even less obvious example… If training for a criterium you need to spend a lot of time in the drops or hooks of your handlebars – not on the brake hoods or tops. Why? Because crit racing demands you be in that position almost all of the race and pedaling economy is different when in the drops versus being on the hoods. Slightly different muscles are used.

You’re probably getting the idea now, but here’s a final one, similar to the above, that is often overlooked by road cyclists… If you want to race well in time trials you need to train on a TT bike. Again, different muscles are used in an extreme aero position than when on a road bike, even in the drops. In the Build period I have riders do muscular endurance intervals on their TT bike weekly.

This specificity principle is applied to periodization by ensuring that your weekly key workouts become increasingly like your next A race the closer in time you get to that race. So let’s examine “key” workouts.

A key workout is one that I have called a “breakthrough” workout in my Training Bible books. It’s a workout intended to push the limits of your fitness. I’ve recently started defining them with a “Training Stress Score” (TSS). I determine very early in the season what the approximate TSS of the A race will be. Then I design workouts based on that stress. I’ve mentioned this concept before here. But I continue to refine it and will post something here in the near future when time allows.

Essentially, a key workout is a hard session. Serious athletes typically do two to four of these in a week during the Build period. If you want to race faster, determining the details of these workouts, when to do them relative to each other, and the rate at which they become increasingly like the A race is what serious training is all about. Missing a key workout is bad but you can recover from it fairly easily. Missing a bunch of them is disastrous to performance.

The bottom line is that these key workouts must be specific to the demands of the A race for which you are training. Specificity isn’t so critical for the non-key workouts in your week. But some is still required. How much is difficult to say. But I’d recommend that a cyclist do them on a bike. That’s probably beneficial, but hard to measure.

It’s a little trickier for triathletes. They probably need to do each of the three sports at least three times a week. That means three key workouts and six “others” every week. Very competitive triathletes do far more than that. In fact, some would probably progress better if they cut back on some of the “filler” workouts.

You can make some exceptions to the specificity principle when it comes to recovery workouts. Triathletes are probably better off recovering on a bike or in the pool rather than by doing an easy run. If you’re going to develop an overuse injury it’s most likely in running. Saving the legs for the key runs is generally a good idea. I still want the triathletes I coach to run at least three times a week. So one of those “other” runs may be to improve skills or as a short run after a key bike ride to prepare the body for the “unusual” stress of running after riding.

At this point I should also get into recovery days in greater detail. That’s a post for another day, however.

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