Anaerobic Exercise: Fast Fuel
Anaerobic exercise: fast fuel
Anaerobic exercise is when you are exercising at a rate that requires your body to use energy systems that do not require the use of oxygen to produce energy from within the muscle. That’s not to say that you are going so fast that oxygen is not being used. Some people error in suggesting that we get to a point where our body doesn’t use oxygen. That isn’t the case. What it means is that the primary source of energy being used at that particular moment is not dependent upon oxygen to produce energy (ATP) to keep you going.
The problem with anaerobic pathways is that they cannot be maintained for a long period of time. When the energy demand exceeds the rate at which it can be produced, you hit the wall and slow down. Slowing down allows for the oxygen dependent system (oxidative or aerobic) to produce more energy and hopefully catch up.
Another myth about anaerobic exercise is that lactic acid creates muscle failure and burning. The fact is that lactate (not lactic acid) can be useful in serving as a bridge between the aerobic pathway and anaerobic pathways.
The point at which the muscle is no longer able to clear out lactate fast enough to be used in aerobic pathways is known as the lactate threshold or anaerobic threshold. This measurement can be used to determine an athletes fitness level just as the maximum amount of oxygen that can be used by the muscle (VO2max).
Currently, there is a considerable amount of research to determine what relationship exists between VO2max and lactate threshold. Both characteristics are important for high level athletes.
Anaerobic threshold can be improved through high intensity interval training. Other sports or activities that require high levels of anaerobic threshold include basketball, soccer, hockey, lacrosse and racquetball just to name a few.
These types of workouts and activities are effective for improving lactate threshold because they tax the body’s ability to clear lactate out of the muscles and become more efficient. High Intensity Interval training (HIIT) routines help achieve this. HIIT allows you to exceed your anaerobic threshold for a period of time by alternating high intensity activities with periods of rest and recovery.
The Real Truth About Lactic Acid
“Feel the burn!” The lactic acid myth revealed!
You hear it all the time in the gym when you feel that burn in the muscle. “Oh that is the lactic acid building up in your muscle. That is why it burns.” Is that really what is happening or is there some other chemical or physiological explanation for the burn you feel. You have probably been sore a day or two after a good workout. Again, some attribute this to lactic acid build up. Can there be another explanation for this?
Yes! The idea that lactic acid is the cause of such discomfort is not supported by basic biochemistry, the chemical reactions that take place in your body. It is true that lactic acid exists. However, lactic acid is not the cause of the soreness or the burn.
Maybe a quick summary of basic chemistry will help. Acids are made up of a “free” hydrogen molecule (not chemically combined with another substance) and a salt molecule such as lactate. Under the right conditions, these two molecules chemically combine to form an acid. One of the most common acids is hydrochloric acid. The number of hydrogen molecules that are “free” determines the pH of a solution. The measure of the concentration of free hydrogens in a solution is known as pH. A lower pH value means that the solution or environment has a greater concentration of free hydrogens (more acidic). A higher pH value means that the solution has a lower concentration of free hydrogens. We call this basic or alkaline.
The value of pH is measured on a scale from 0 to 14. Stomach acid has a pH of around 2. Water has a pH of around 7 and liquid drain cleaner has a pH of around 14. When you combine a base and an acid, the solution moves closer to the neutral pH around 7. That is why you add baking soda to your pool if the pH is too low and muriatic acid if the pH is too low. By doing so you are providing a salt for the hydrogen to bond to thereby reducing the concentration of free hydrogens. This increases the pH
At a pH of 3.86 lactate bonds with free hydrogens to form lactic acid. However, when the pH is greater than 3.86 lactic acid becomes sodium lactate and does not contribute to the free hydrogens in the blood, which has a pH of around 7. Even during intense exercise the pH of blood does not drop very far below this. Therefore, lactic acid really does not exist in the body. In fact, the production of lactate in the blood during exercise helps to make the blood more basic and neutralize the pH.
The burn you feel during your workout is not a result of lactic acid. Nor is lactic acid the so-called “toxin” that is released when you get a massage. But that’s another story…
For more detailed information on the biochemistry involved please see the following article by Robert A Robergs:
Exercise-Induced Metabolic Acidosis: Where do the Protons come from?
Lactic Acid – Your Friend?
Lactic Acid Not Athlete’s Poison, But An Energy Source — If You Know How To Use It
ScienceDaily (Apr. 21, 2006) — In the lore of marathoners and extreme athletes, lactic acid is poison, a waste product that builds up in the muscles and leads to muscle fatigue, reduced performance and pain.
Some 30 years of research at the University of California, Berkeley, however, tells a different story: Lactic acid can be your friend.
Coaches and athletes don’t realize it, says exercise physiologist George Brooks, UC Berkeley professor of integrative biology, but endurance training teaches the body to efficiently use lactic acid as a source of fuel on par with the carbohydrates stored in muscle tissue and the sugar in blood. Efficient use of lactic acid, or lactate, not only prevents lactate build-up, but ekes out more energy from the body’s fuel.
In a paper in press for the American Journal of Physiology – Endocrinology and Metabolism, published online in January, Brooks and colleagues Takeshi Hashimoto and Rajaa Hussien in UC Berkeley’s Exercise Physiology Laboratory add one of the last puzzle pieces to the lactate story and also link for the first time two metabolic cycles – oxygen-based aerobic metabolism and oxygen-free anaerobic metabolism – previously thought distinct.
“This is a fundamental change in how people think about metabolism,” Brooks said. “This shows us how lactate is the link between oxidative and glycolytic, or anaerobic, metabolism.”
He and his UC Berkeley colleagues found that muscle cells use carbohydrates anaerobically for energy, producing lactate as a byproduct, but then burn the lactate with oxygen to create far more energy. The first process, called the glycolytic pathway, dominates during normal exertion, and the lactate seeps out of the muscle cells into the blood to be used elsewhere. During intense exercise, however, the second ramps up to oxidatively remove the rapidly accumulating lactate and create more energy.
Training helps people get rid of the lactic acid before it can build to the point where it causes muscle fatigue, and at the cellular level, Brooks said, training means growing the mitochondria in muscle cells. The mitochondria – often called the powerhouse of the cell – is where lactate is burned for energy.
“The world’s best athletes stay competitive by interval training,” Brooks said, referring to repeated short, but intense, bouts of exercise. “The intense exercise generates big lactate loads, and the body adapts by building up mitochondria to clear lactic acid quickly. If you use it up, it doesn’t accumulate.”
To move, muscles need energy in the form of ATP, adenosine triphosphate. Most people think glucose, a sugar, supplies this energy, but during intense exercise, it’s too little and too slow as an energy source, forcing muscles to rely on glycogen, a carbohydrate stored inside muscle cells. For both fuels, the basic chemical reactions producing ATP and generating lactate comprise the glycolytic pathway, often called anaerobic metabolism because no oxygen is needed. This pathway was thought to be separate from the oxygen-based oxidative pathway, sometimes called aerobic metabolism, used to burn lactate and other fuels in the body’s tissues.
Experiments with dead frogs in the 1920s seemed to show that lactate build-up eventually causes muscles to stop working. But Brooks in the 1980s and ’90s showed that in living, breathing animals, the lactate moves out of muscle cells into the blood and travels to various organs, including the liver, where it is burned with oxygen to make ATP. The heart even prefers lactate as a fuel, Brooks found.
Brooks always suspected, however, that the muscle cell itself could reuse lactate, and in experiments over the past 10 years he found evidence that lactate is burned inside the mitochondria, an interconnected network of tubes, like a plumbing system, that reaches throughout the cell cytoplasm.
In 1999, for example, he showed that endurance training reduces blood levels of lactate, even while cells continue to produce the same amount of lactate. This implied that, somehow, cells adapt during training to put out less waste product. He postulated an “intracellular lactate shuttle” that transports lactate from the cytoplasm, where lactate is produced, through the mitochondrial membrane into the interior of the mitochondria, where lactate is burned. In 2000, he showed that endurance training increased the number of lactate transporter molecules in mitochondria, evidently to speed uptake of lactate from the cytoplasm into the mitochondria for burning.
The new paper and a second paper to appear soon finally provide direct evidence for the hypothesized connection between the transporter molecules – the lactate shuttle – and the enzymes that burn lactate. In fact, the cellular mitochondrial network, or reticulum, has a complex of proteins that allow the uptake and oxidation, or burning, of lactic acid.
“This experiment is the clincher, proving that lactate is the link between glycolytic metabolism, which breaks down carbohydrates, and oxidative metabolism, which uses oxygen to break down various fuels,” Brooks said.
Post-doctoral researcher Takeshi Hashimoto and staff research associate Rajaa Hussien established this by labeling and showing colocalization of three critical pieces of the lactate pathway: the lactate transporter protein; the enzyme lactate dehydrogenase, which catalyzes the first step in the conversion of lactate into energy; and mitochondrial cytochrome oxidase, the protein complex where oxygen is used. Peering at skeletal muscle cells through a confocal microscope, the two scientists saw these proteins sitting together inside the mitochondria, attached to the mitochondrial membrane, proving that the “intracellular lactate shuttle” is directly connected to the enzymes in the mitochondria that burn lactate with oxygen.
“Our findings can help athletes and trainers design training regimens and also avoid overtraining, which can kill muscle cells,” Brooks said. “Athletes may instinctively train in a way that builds up mitochondria, but if you never know the mechanism, you never know whether what you do is the right thing. These discoveries reshape fundamental thinking on the organization, function and regulation of major pathways of metabolism.”
Brooks’ research is supported by the National Institutes of Health.
University of California – Berkeley (2006, April 21). Lactic Acid Not Athlete’s Poison, But An Energy Source — If You Know How To Use It.
What is HIIT?
What is HIIT? by Greg McKenzie
High Intensity Interval Training is a certain type of routine used in training primary focused on those trying to lose fat. There are many distinct goals and differences this type of routine has that makes it stand out from all the others.
Only 20 minutes is needed not including warm ups and cool downs. Twenty minutes may not seem like much time, but if done correctly, this workout will exhaust you. High Intensity Interval Training’s goal is to maintain an anaerobic state over a period of time. Allowing you to sprint harder for longer periods, it’s designed with rest intervals. Depending on how fast you were, for example, if you were to sprint for 100 meters, you would go full out for about 15 seconds. Start out at only about 4 to 6 minutes if you are a beginner, but an advanced High Intensity Interval Training routine will eventually allow you to go all out for 7 to 8 minutes.
High Intensity Interval Training allows for a range of different activities. Using the largest muscle groups in your body safely is important when choosing an activity. The energy source found inside the muscle is tapped by the High Intensity Interval Training. Your benefits increase with an increase in the size of the exercised muscle group.
Sprinting is the ideal choice for High Intensity Interval Training. Pick another activity if you have injuries or problems which may prevent you from sprinting. One excellent option is using a stationery spinning bicycle.
High Intensity Interval Training routines are not designed to be done on consecutive days. The goal of a workout is to operate at quite a high intensity. In order to maintain this level of exertion, put as much effort as possible into your reps. This is when High Intensity Interval Training is at its most productive. After working out, give your muscles time to regain energy. You have a much greater chance of injuring yourself if this doesn’t happen, and you will not be able to workout with as much intensity as before. The more rested you are, the more intensity you can put into your workout, getting the benefits in your body during your rest period.
It was believed that doing High Intensity Interval Training on an empty stomach was the optimal method for maximum fatloss. However, new studies have shown that this is not the case. Before you exercise, make sure you eat something balanced and easily digestible; also ensure that your meal is not too heavy before you exercise.
One of the goals of High Intensity Interval Training is for continuous improvement, never to hit a wall, or plateau. High Intensity Interval Training capitalizes on your body’s natural ability to continuously adapt to increasing levels of demand; because of this innate ability, your body inevitably will adapt to whatever you demand of it. Your goal results will not be as quick if this occurs. Avoid this by keeping your body guessing. After eight weeks on one High Intensity Interval Training program, take a week off and start a different routine. There are many options available.
To find the secrets to High Intensity Interval Training visit IntervalTraining.net
About the Author
Greg McKenzie is the creator of IntervalTraining.net, the most complete resource on Interval Training and HIIT on the Internet
What is Interval Training?
What is Interval Training?
by Aaron Ivey
The term “interval training” has become quiet the buzz word over the past year. So what is it and how does it work? First off, interval training is not a new technique for athletic performance improvement. Athletes have made interval training a part of their training for many years. Fartlek training is a good example of a training technique based on the same principles. Interval training is simply combining periods of high intesity exercise with low intensity exercise. You can apply interval training no matter what your level of fitness.
Many studies indicate that the use of interval training with “untrained” individuals is more effective at decreasing a person body fat than long slow distance training like most people are used to doing. They also got in shape faster. Here is a personal example. Several years ago I was looking to supplement my income a little and decided that I would deliver newspapers in the early morning. Well, instead of driving my car to each individual house, getting out. letting the engine run, and move on, I decided I would park my car, grab as many papers as I could carry and run from one house to the next. I would then get in the car and drive to the next area. This short duration, high intensity exercise with rest in between is what interval training is all about. Within 3 or 4 weeks I noticed that my pants were a little loose and I wasn’t quiete as out of breath coming back to the car.
So how does it work? Think of your body as having 3 different types of fuel, or energy systems, to use. I will use the metaphor of starting a fire to help illustrate. The first fuel is easily ignited and burns really quickly (think of a match). The second fuel takes a little more effort to get it going but will burn for a little longer than the first (think of the kindling). The third energy system takes quiet a bit of effort to get started and burns really slow and long (think of the oak log). Each of these systems has fancy scientific names attached to them. Maybe in another blog I will go into further detail.
When you are doing interval training you are burning matches like crazy and some of the kindling, depending on how long your exercise bout is. During your recovery period, which could last up to 3x the length of your exercise bout, your body uses energy from the oak log to rebuild your matches. The oak log uses fat for energy and to replace the energy used during the match phase and the kindling phase.
By using high intensity interval training you are training your body to use fat to replenish your emergency fuel sources.
