Category Archives: metabolism

Common Triathlon Training Metrics

Posted on by
Reply
Source

Source

Over the past two weeks I have outlined how to conduct a heart rate test and a functional threshold power test; but, I realized that I should have started from the beginning. What are the various training metrics that a triathlete should use?

Coaches, athletes, and endurance sport authors love to talk training metrics and terminology. Lactate threshold. VO2max. Cardiac output. Heart rate. Power. Rate of perceived effort. The list can go on and on…

Let’s look at a few key metrics that any triathlete or endurance sport athlete should understand, or at least a basic understanding.

  • Heart Rate – The very basic definition of a heart rate is the number of heartbeats per unit of time. Heartbeats are created when blood flows through the heart and the values open and close creating an audible sound. The normal human heart beats at 60-100 beats per minute (bpm). This, of course, depends on various factors such as fitness, age, stress, etc. Heart rate in fitness is an important metric because it can measure an athlete’s fitness. Through regular endurance training, the heart becomes stronger and thus can pump more blood with each beat. As a result, the heart doesn’t have to work as hard, and the athlete’s heart rate at rest and during exercise will be lower. Measuring an athlete’s heart rate over time is a good way to measure improvement in an athlete’s endurance fitness. See how to conduct a heart rate test for more information on heart rate-based training.
  • Cardiac Output – Cardiac output is measured as the amount of blood that the heart pumps through the body at a single minute. An increase in cardiac output is important because more blood is delivered to the important organs, such as the brain and liver. Cardiac output increases with regular endurance training. During endurance sports, cardiac output is an important metric because it means that more blood is delivered to the working skeletal muscles during a workout. As a result, more oxygen is transported to the muscle cells to produce energy and other metabolic waste by-products are removed from the working muscles more rapidly.
  • VO2max – Endurance training not only improves cardiovascular fitness, but also improves lung capacity during exercise. Endurance training generally improves an athlete’s respiratory rate (breathes per minute) and tidal volume (amount of air per breath). Improvements in respiratory rate and tidal volume can contribute to an increase in maximal oxygen uptake, also known as VO2max. VO2max is defined as the highest volume of oxygen that a person’s body is capable of taking in and using during aerobic energy production. An improvement in VO2max is important for endurance athletes because it means more oxygen is available to working muscles for energy production during exercise.
  • Lactate Threshold – Lactate threshold represents the point at which the athlete’s body requires a greater contribution from the glycolysis energy system (anaerobic system) and a smaller contribution from the oxidative phosphorylation energy system (aerobic system). At this point, lactate production exceeds the lactate removal rate and blood lactate levels increase. One of the primary goals of endurance training should be to increase an athlete’s lactate threshold.
  • Power – Power is primarily a cycling metric. It is simply defined as the rate of doing work, where work is equal to force times distance. Power is measured via a power meter on a bike. See How to Conduct a Functional Threshold Power test for more information on power-based training.
  • Rate of Perceived Effort – Rate of Perceived Effort, or RPE, is a psychophysiological scale, meaning that it calls on the mind and body to rate one’s perception of effort. The traditional scale called the Borg Scale is based on a scale of 6-20, where a score of 6 is equivalent of no exertion and a score of 20 is equivalent of maximum exertion. Many coaches and trainers, myself included, will use a scale of 1-10 for easier understanding by the athlete/client.

Above are several common exercise physiology and training metrics terminology that are often thrown around by athletes, coaches, and endurance sport authors. Of course, there are many more that we could discuss.

~ Happy Training! 

Book Review: Fat Chance

Posted on by
Reply

Looking for a good book? This is one MUST READ book! I enjoy listening to podcasts while working sometimes. My favorite podcast is Vinnie Tortorich, America’s Angriest Trainer. I HIGHLY recommend you listen to his podcast and then go out and buy his bestselling book, Fitness Confidential. I will be doing a book review of that very shortly. Vinnie has always recommended Dr. Robert Lustig’s Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease on his podcast and after IMLP I finally had some free time to pick it up and finish it.

Source: Amazon

Source: Amazon

I’ve read a lot of books within the past month and Lustig’s is by far the best one to read. I think this book should even be a required reading book in high schools and college. That’s how much I think everyone needs to read this book. Go buy it. Now!

Who is Dr. Lustig? Well, he is an internationally renowned pediatric endocrinologist who has spent the past 16 years treating childhood obesity at some of the top hospitals in the world, such as St. Jude’s Children’s Hospital and UCSF Benioff Children’s Hospital. Sooo… I would say that he knows his shit better than those Jillian Michaels and Dr. Oz characters.

Dr. Lustig became famous for his at-the-time, very controversial you-tube video called “Sugar: The Bitter Truth.” And, yes, I think you should watch that too. Fat Chance documents the science and politics that have led to the current obesity pandemic that no longer just affects the United States, but the entire world. I went on a medial mission to Costa Rica and Nicaragua in 2011 and I was surprised beyond belief the number of overweight and obese people and the number of fast-food joints in those countries. Hell, Costa Rica has a Denny’s!

Lustig reveals and outlines all the bad research that has been conducted over the years by the government and big food. Personally, I think a lot of those scientists who were involved in many of those studies should have their PhD’s removed. It’s rather disgusting how many people will sell-out to the food industry and politicians. Ok, end rant.

The book begins by setting up a valid argument why the government’s view of “calorie in, calorie out” is bullshit. I hate that term. When discussing food with my clients I always ask them “what is a calorie?” No one has yet to answer correctly. It’s because we have been brainwashed over the years to think of food as calorie in, calorie out. That’s how you’re suppose to lose weight, right? Wrong! Believe me, I was one of those people for a long time too, but the more I read (from reputable and educated sources!!) the more I learn that I have been completely duped all my life. Lustig is an endocrinologist meaning that he is a specialist in hormones and the biochemistry of the human body.

Lustig talks a lot about hormones, ya know, since he gets hormones. Hormones have a profound effect on our metabolism and how we view food. Fat Chance outlines ways to readjust our key hormones that regulate hunger, reward, and stress. That is done mainly by eliminating sugar. Sugar is an addictive toxin to our bodies. We live in a society today that thinks dietary fat is bad. Low-fat this and low-fat that. Well, guess what happens when you remove fat from food products? The food tastes like crap and the manufactures pump it full on sugar. Read the book and find out why sugar is bad for you. I’m serious, do it.

The evolution of nutritional science is what really fascinates me. Back in the early to mid-1900’s we got the science right. And then big food and some idiots got involved. The leading cause of death today in the United States is heart disease, but in the next decade or so we will see that shift to diabetes and other metabolic-related diseases, which heart disease can be considered one. In 1957 John Yudkin, a British physiologist and nutritionist, postulated that a dietary component caused heart attacks. By 1964, through natural observation studies he theorized that the consumption of sucrose was associated with heart disease. Yudkins published numerous papers on the biochemistry of sucrose and was the first person to warn us that excessive consumption could lead to heart disease, diabetes, GI diseases among other diseases.

Now, back in the United States we have Ancel Keys, a Minnesota epidemiologist. In the early 1950s Keys spend some time in England where we witnessed a large rise in heart disease. The typical English diet consisted of high fat and high cholesterol items, such as fish and chips. He noticed that those who are well fed in both the US and UK were those who could afford meat, but also seemed to suffer the most from heart disease. In the 1960s and 1970s Keys published numerous studies indicating that heart disease patients had higher cholesterol levels than non-heart disease patients. In 1980 Keys published his “Seven Countries” study, a 500-page paper that concluded that dietary fat was the single cause of heart disease. Which, the United States government and medical community has since run with. However, there are four major problems with his thesis.

The first being that his Seven Countries study started out as a Twenty-two Countries study. The seven countries he used in his study were: Japan, Italy, England, Wales, Australia, Canada, and the US. The relationship between dietary fat and heart disease looked quite convincing when the data was plotted. However, when he plotted the other countries (Austria, Ceylon, Chile, Denmark, Finland, France, Germany, Ireland, Israel, Mexico, Netherlands, New Zealand, Norway, Portugal, Sweden, and Switzerland), the correlation was almost non-existent. He also actively chose not to include indigenous tribes, such as the Inuit, Tokelau, and Maasai and Rendille, who eat only animal fat and have the lowest prevalence of heart disease on the planet. How’s that for science? Second, the role of dietary fat in heart disease is complicated by trans fat, which has signficant scientific studies to link it to metabolic syndrome. The use of trans-fats peaked during the 1960s and most likely were not considered a variable by Keys.

Third, if you look at the correlation itself, it is a problem. Japan and Italy eat the least amount of saturated fat and have the least amount of heart disease. But, they also eat the least amount of dietary sugar out of all the countries included. How do you know if it’s the sugar or the fat causing heart disease? Fourth, Keys admits that he correlated sucrose with saturated fat, but it was not important enough to him to remove sucrose from the equation. When one completes a multivariate correlation analysis, a common statistical tool that determines whether A causes B regardless of the impact of C, D, and E, one has to do the calculation both ways. In other words, Keys would have had to hold sucrose constant and show that dietary fat still correlates with heart disease. Basically, Keys used bad science. And then the government took it and ran with the idea.

This is just one of the studies Lustig discusses in his book. He discusses many more that are just as interesting. The end of the book concludes with two sections. One is on the personal solution and the other is on the public health solution. I absolutely loved the public health section because I am a public health professional. In society today we have this notion that obesity is an individual problem. That person eats too much, doesn’t exercise and it’s their fault they are fat. Lustig will tell you that’s rarely the problem. The public health section discusses ways as a society that we can conquer the impending obesity pandemic.

Overall, you will be crazy not to read this book. Out of all the books I have read this year, this is by far one of the best ones out there. It will change your view of nutrition and the obesity epidemic. Lustig gives you the science that backs up his claims. This isn’t a diet book written by some bimbo Hollywood trainer on how to lose 10-lbs in 10 days. It’s a real book based on real science that will open your eyes and mind to the current nutritional crisis in the United States.

What are you waiting for? GO BUY THE BOOK! 🙂

~ Happy Training!

Nutrition Tuesday: Fats Aren’t Evil!

Posted on by
Reply
(Source)

Fats seem to be a dirty word to many people. Before the low-carb focus in diet trends, dietary fat was the primary target of public and academic condemnation. It is important, especially for athletes, to understand the basic chemistry of fat (not all fats are created equally!) and the metabolism of fat. First, let’s look at some definitions to clear up the air about evil fats…

Lipids – A class of molecules that are composed of triacylglycerols, sterols, and phospholipids.
Triacylglycerol (also called triglyceride) – A glycerol “backbone” molecule with three fatty acids. One gram of triacylglycerol (TAG) provides 9 kcal of energy to the body when utilized.
Glycerol – A three-carbon molecule that is “backbone” of TAGs. By itself, glycerol is a “sugar” and when released from storage, it can be recycled by the liver to create new blood glucose.
Fatty acids – Chains of carbon atoms of various lengths that attach to a glycerol molecule to form TAGs. A fatty acid with no double bonds is called a saturated fatty acid. A fatty acid with one double bond is called a monounsaturated fatty acid and a fatty acid with two or more double bonds is called a polyunsaturated fatty acid.

An example of an unsaturated TAG

Fats are interesting in how they are stored in the body. Once fats are digested, they are packaged into chylomicrons, which are lipoprotein particles that transport dietary fats from the intestines to other parts of the body1. Once the digested fats have reached their targeted cells, they are either stored or used depending on the person’s physiological state. The infamous “fight or flight” hormones (i.e. adrenaline) and muscular contractions (only up to a certain point though) induce fat breakdown and burning in the processes called lipolysis and oxidation. If the body is in the “restive-digestive” state, the hormones secreted during this stage and the relative lack of muscular activity induce fat building/storage called lipogenesis1. 
Dietary fats are physiologically different than other major micronutrients because fatty acids can be incorporated into the phospholipid bilayer of the cell membrane, which ultimately can lead to membrane fluidity changes and different physiological effects of the body, such as inflammation or blood clotting. What is the phospholipid bilayer of the cell membrane you ask? Well, think back to your high school biology days… okay, depending on your age, your biology book might not have covered the phospholipid bilayer. In a nut shell, a phospholipid bilayer is a think polar membrane made up of two layers of lipid molecules. Cell membranes of almost all living organisms and many viruses are made of a lipid bilayer. It serves as a barrier to keep ions, proteins, and other molecules where they need to be and prevent them from “running away.” Phospholipids have a “water-loving” head and a “water-hating” tail. Thus the “water-loving” heads face out and the “water-hating” tails always face inward. And that’s all you really need to know about that, but I could go on for days about the topic.

Here’s a nerdy video of the plasma membrane 🙂
Certain fatty acids are known to be essential, sort of like certain amino acids, because the human body is unable to create them in the body; thus, these fatty acids must be obtained through diet. These essential fatty acids are called linolenic (Omega 3) and linoleic acid (Omega 6). 
Omega-3 and omega-6 fatty acids are important in the normal functioning of all tissues of the body. Adequate intake of these essential fatty acids have shown in studies to help prevent atherosclerosis, reduce the incidence of heart disease and stroke, and reduce joint pain among other things2. 


Stored cellular fat in the form of TAG is the primary fuel source during fasting periods lacking intense physical exertion1. Research has shown that about 60% of a human’s “fuel mix” at rest – in a fasted state- is from fat1. So, now you think you can become a couch potato and burn fat! Sounds great doesn’t it? But, that’s not how it works. Just sitting there on the couch and watching television requires very little caloric expenditure and thus “60% of nothing is still nothing!”1 So get off your butt and start moving!
The use of fatty acids during physical activity is an interesting relationship. A couple weeks ago I discussed metabolism. If you need a review, click HERE. There is a direct relationship between fat use and exercise duration. The longer you exercise at a low-moderate pace (i.e. your endurance pace and/or Zone 2 heart rate), the greater your fat breakdown and “burning.” However, there is an inverse relationship between fat use and intensity. The more intense you exercise, the less stored fat can contribute (i.e. your body switches to mainly carbs). 
It is important to include healthy fats (i.e. monounsaturated and polyunsaturated fats) and in your diet because fats serve the following functions in your body:
  • Fat is used by your body for fuel because it is the most energy-dense macronutrient and they provide most of the body’s tissues and organs (including your heart!) with their energy1
  • Cell membranes are composed of phospholipids
  • Fats are critical for the transmission of nerve signals that generate muscle contractions1
  • Serve as a transporter for vitamins A, D, E, and K1
  • Provide cushioning for the protection of vital organs and insulation from cold environments1
References
  1. Antonio J, et al. Essentials of Sports Nutrition and Supplements. Totowa, NJ: Humana Press, 2008.
  2. Physicians Committee for Responsible Medicine. Essential Fatty Acids. Available at: http://www.pcrm.org/health/health-topics/essential-fatty-acids. Accessed June 4, 2012.   
(Disclaimer: Once again this is for your information only. If you feel you need help with your diet and health then I urge you to seek professional medical and nutrition advice from an expert.)

Heart Rate Testing! Oh My!

Posted on by
4
Last night was my first official heart rate test on the trainer to determine my heart rate zones for training. It involved a 15 minute time trial (TT) at an all out effort. The only other time I did something similar to this was a few weeks ago at the Sustainable Athlete’s Friday Night Fight on a 10km rolling hills course. Honestly, it’s not about the HR so much as it is a lesson in pacing. Go out too fast and you’ll blow up half way. Go out and continue to slow and you won’t reach your maximum effort and will probably lose. As you’ll see below in my graph my pacing isn’t the best, but it’s something that I will learn to perfect in the future. This year’s training plan is much different than ways I’ve trained in the past. HR training, power (soon-to-be), 2-a-day workouts, etc. I’ve finally put my big girl pants on and stepped up to the big leagues! I’m excited to see the differences in my performance as my training continues to progress.

Now let’s talk about this HR test! I went into dreading it slightly because I knew it would hurt. After the last TT I was very light-hearted and considered puking. I was sure I was going to feel the same way after this one! I made sure I had a bucket ready next to my bike in case I couldn’t un-clip fast enough. I also informed my father as he was walking out the door that I might be dead on the floor from a heart attack when he comes home. He succeed to ask me if I paid my life insurance. Well, no, I don’t have life insurance because I’m 24, not married and no kids. What’s the point? He said he would just sell my bike to pay for my funeral. Thanks, Dad. My workout looked like this:

15 min warm up at endurance pace (~65% effort)

3×1 min (1 min rest btw interval) of fast pedaling (100+ rpm)

5 min easy spin

2 min all out effort

10 min easy spin

15 min TT (start slightly below threshold, build speed, and finish the last 2 mins at all out effort)

spin easy till 1:10 total time

Let’s talk a little bit about HR training. HR training is useful for many endurance athletes because it teaches your body to use fat as it’s main source of fuel instead of carbohydrates. Now, I can certainly explain cellular metabolism to you because I love biochemistry, but I’m not because you probably don’t care. Your body creates energy in the form of adenosine triphosphate (ATP) through several complex biochemical reactions from the nutrients (i.e. foods) you consume. However, each nutrient (i.e. carbohydrates, fat, and protein) is processed differently during metabolism. Carbohydrates are the main source of fuel for exercise of medium to high intensity, while fats fuel low intensity exercise for longer periods of time. Protein can be processed for fuel, but is mainly used by the body for repair and maintenance of your tissues. Your body converts nutrients to fuel by two different methods: aerobic (with oxygen) metabolism and anaerobic (without oxygen) metabolism. There are two forms of anaerobic metabolism: ATP-creatine phosphate and glycolysis. I will not bore you with the details, but the overall outcome is energy for short, intense bursts of exercise (i.e. 100 meter dash). In case your wondering, lactic acid is a by-product from the glycolysis cycle of metabolism.

Aerobic metabolism is the focus of most endurance athletes. Aerobic metabolism requires oxygen that is transported through your circulatory system. Cells (or most precisely, mitochrodria in cells) use nutrients such as carbohydrates, fats, and proteins and oxygen molecules to produce ATP for energy. Fat is a great source of nutrients for endurance training. We all have fat storage in our bodies. Some of us, including myself, probably have too much of it! If you are training at low intensity, generally at or below 50% of your max HR, you have enough stored fat to last for hours or even days. However, if your intensity picks up, your body will switch to carbohydrates as your main source of fuel since it is more efficient. The downfall is that carbohydrates are stored as glycogen in your body and it is a finite source. A typical person’s glycogen source lasts for about 2 hours before they reach the “bonk.”

Now let’s get back to HR training. There are several ways to calculate your maximum heart rate (MHR) and your heart rate zones. One is the traditional calculation of 220- your age. This as it’s limitations, especially because it’s inaccurate for women. A better calculation for females is 209 – (0.7 x age). According to this calculation my MHR should be 191.5. Joe Friel suggests doing a 30 TT on your bike. Everyone has there own methods.

Now let’s look at my graph from my HR test. I even added commentary to it for you! (Let’s hope it’s big enough for you to read!) This was my thought process throughout the whole ordeal.

It was a good time. I didn’t puke at the end, but I definitely saw stars during the last two minutes where I pushed it hard. My max rate was 191 with an average of about 184 during the 15 min TT. From this and what I imputed into marathonguide.com’s HR Zone calculator we get this for my zones:

Zone 1 – low intensity (50-60% of MHR): 125-138

Zone 2 – weight control (60-70% of MHR): 138-151

Zone 3 – aerobic zone (70-80% of MHR): 151-164

Zone 4 – anaerobic zone (80-90% of MHR): 164-177

Zone 5 – maximal zone (90-100% of MHR): 177-190 (aka puke)

Now this is my intrepretion of my data. My coach might tell me otherwise. Plus I have to do a HR test on Saturday for running. I seriously might actually puke on that one. We’ll see what happens!

After completing my test, I logged into facebook to see this awesome picture pop up. I wish I saw this beforehand. It’s now my background on my work computer because I love it so much!

And because my artistic skills are not up to par. This is what my dog did while I sweated gallons of sweat all over my poor little bike. I told her to call 911 if I passed out, but I think she would have left me for dead. Thanks Reagan!