Dr John Berardi, president and founder of Science Link, Inc., completed his doctorate at the University of Western Ontario in Canada in the field of exercise biology and nutritional biochemistry. Dr. Berardi's ongoing research into nutritional optimization for athletic performance and body transformation are the basis of his exercise and nutrition systems.
The Benefits of Training The Anaerobic Energy Systems
While training the anaerobic energy systems is clearly of benefit for enhancing athletic performance, there are many other non-athletic benefits as well:
1) This type of training is very calorie expensive. Short, 30-minute workouts can burn in excess of 400kcal during the exercise. While carbohydrates provide much of the fuel used during the high intensity interval, fat is also burned preferentially during the low intensity aerobic recovery period between the high intensity intervals.
2) The post exercise calorie expenditure is huge with this type of exercise. In some studies the resting metabolic rate remains elevated (by 15% or more) up to 24 hours after the workout. Interestingly, after exercise the body preferentially burns fat so this elevated metabolism is burning predominantly fat.
3) This exercise leads to an up regulation of aerobic, anaerobic, and ATP-PC enzyme activity. This means that all the energy systems of the body will operate at higher levels and become efficient at burning calories and generating energy.
4) The muscles used during this type of exercise will change their composition, shifting toward an increased percentage of fast twitch fibers. This increase in power-producing fast fibers comes at the expense of the weaker slow twitch ones. The shift is desired as the fast fibers grow more easily than the slow fibers.
5) There is an increase in specific muscle cell organelles (i.e. the sarcoplasmic reticulum). This leads to a better calcium balance and contractile ability.
6) There are short-lived increases in blood testosterone (38%) and growth hormone concentrations immediately after exercise. While this is debatable, these changes may contribute to an anabolic state in the body.
H.I.I.T. What Is It?
High Intensity Interval Training
•The repeated alternating of periods of high intensity effort with periods of low intensity effort.
•The basic tenets of interval training can be satisfied on a treadmill, stationary bike, elliptical machine, ergometer or outside, with the latter ‘probably’ being the most effective.
•Normally defined by a ‘work:rest’ ratio (e.g. 1:3), in which the ‘work’ component represents the high intensity/sprint component and the ‘rest’ represents the low intensity/active recovery component.
•For example, alternating 20 second fast runs with 60 second brisk walks (or jogs) until the desired time has elapsed.
•Typically shorter in duration than traditional low intensity cardio owing to the higher intensity effort.
The Benefits of Interval Training Relative to Endurance Cardio
1. Greater Energy Expenditure and Resultant Fat Loss
•With increasing exercise intensities, the proportion of energy substrate derived from fat decreases, while the proportion of carbohydrate usage increases.
•However, the predominant fuel substrate used during exercise does not play a significant role in fat loss.
•Total daily energy expenditure is more important for fat loss than the major fuel used during exercise.
•The most notable study comparing interval training to endurance cardio concluded that interval training is the most optimal method for fat loss.
In this study subjects engaged in either an endurance program (4-5 times per week for 30-45 minutes) for 20 weeks or a high-low intensity program for 15 weeks.
Neither group was placed on a diet.
The mean estimated energy cost of the endurance protocol was 120.4 MJ, whereas the mean estimated energy cost of the high-low intensity protocol was only 57.9 MJ. (more than double)
However, the decrease in six subcutaneous skin folds was greater in the high-low intensity group than it was in the endurance group. This is despite the lower energy cost during exercise.
After statistical analysis it was shown that the high-low intensity group experienced nine times the fat loss of the endurance group.
This same study found the high-low intensity protocol to significantly increase the activity of an enzyme which is a marker of the activity of ‘fat burning’ over endurance protocol.
•While one burns less overall calories and less fat during interval training (due to the involved energy systems) compared to endurance cardio, when the post-exercise recovery period is factored in, interval training leads to significantly greater energy expenditure and fat loss.
•This is due to the effects interval training has on excess post-exercise oxygen consumption (EPOC)
EPOC – post-exercise oxygen consumption above resting values used to restore the body to the pre-exercise condition.
After exercise, oxygen uptake remains above pre-exercise levels for a period of time that varies according to the length and intensity of exercise.
•The number of calories burned following interval training is significantly enhanced due to the increased EPOC.
•There is much research to show that interval training protocols result in significantly greater post-exercise energy expenditure and fat utilization when compared to low to moderate intensity protocols.
•Another study showed that even with no significant difference in total work, groups that exercised at a high intensity lost significant amounts of fat, while no significant changes were found in the lower intensity group.
•Another study showed that those who participated in high intensity exercise had lower skin fold measurements and waist-to-hip ratios than those who participated in lower intensity exercise.
•Improved VO2max, as a result of interval training, has been associated with increased thermic effect of food (TEF)
TEF – An increase in energy expenditure due to an increase in cellular activity associated with digestion.
2. Improved Cardiovascular Conditioning & Fitness
•Interval training has been shown to increase both aerobic and anaerobic capacity whereas endurance cardio only increases aerobic capacity.
•It is well established that interval training increases aerobic capacity/VO2 max more than endurance cardio.
28% increase in aerobic capacity with high-low intensity cardio vs. 14% increase in aerobic capacity with endurance cardio.
•Maximal oxygen uptake, or V02max, is generally regarded as the best single measure of aerobic fitness.
•Interval training is more conducive to improving the muscle's ability to use fat. The more fit one becomes, the more likely they are to use fat as fuel for any given activity.
•Post training, you will burn more fat. Numerous studies show that HIIT can elevate your metabolic rate significantly after the workout – with most of the calories coming from fat.
•Fat/calorie burning is elevated afterwards to restore homeostasis (i.e. body temperature, catecholamines, hemoglobin, myoglobin, etc.).And it doesn't matter if you eat carbs right away either. This will not inhibit the oxidation of fat. In fact research actually shows that getting nutrients in immediately after HIIT will actually increase EPOC, reduces muscle protein catabolism, and increases recovery, all while having the wonderful benefit of not inhbiting lipolysis.
•HIIT dramatically increases the amount of GH released into the bloodstream. This has some fat burning implications. (muscle building benefits are questionable)
•Long periods of low-intensity/steady state cardio tend to convince some fast-twitch fibers to convert to slow-twitch fibers (or at least take on some slow twitch qualities). Conventional slow, long-duration cardio workouts tend to "overtrain" the fast-twitch muscle fibers and to convert the intermediate muscle fibers to slow-twitch suitors. HIIT prevents this from occurring, preserving your muscle growth potential.
•High intensity cardiovascular exercise increases oxygen expenditure and forces the body to adapt by becoming more efficient at oxygen transport (increase in VO2 max). That means healthy benefits for the heart, lungs and other components of your cardiovascular and pulmonary systems.
Training the Anaerobic Energy System - Dr J Berardi
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Storm Petrel
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When does "endurance" become "intervals"? The only numbers shown, if they refer to C2s, seem to indicate that the "endurance" work should be called a stroll in the park (120MJ in 55 hours), and the hard work (400kCal in 30') is a UT2. So it seems UT2 is better than nothing, and any other conclusion is slightly overdrawn.
08-1940, 179cm, 83kg.
reference info?
This is interesting, and I'd like to read the study directly. But I don't see it listed in PubMed, and I don't see it mentioned on the ScienceLink site. Can you supply a link to where you saw it? Thanks.
ET
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Storm Petrel
- 1k Poster
- Posts: 112
- Joined: April 19th, 2007, 8:38 pm
- Location: USA
Re: reference info?
A Weights Trainer sent it to me (as posted) in his newsletter. The cited reference link: http://www.bodybuilding.com/fun/berardi29.htmturnere wrote:This is interesting, and I'd like to read the study directly. But I don't see it listed in PubMed, and I don't see it mentioned on the ScienceLink site. Can you supply a link to where you saw it? Thanks.
The NY times had an article on this in last tuesday's science times.
(its listed under Health -> fitness and nutrition rather then science.
The link is:
http://www.nytimes.com/2007/05/03/fashi ... dnutrition
(its listed under Health -> fitness and nutrition rather then science.
The link is:
http://www.nytimes.com/2007/05/03/fashi ... dnutrition
The article I linked to in the previous post is pasted in below:
A Healthy Mix of Rest and Motion
By PETER JARET
Published: May 3, 2007
SOME gymgoers are tortoises. They prefer to take their sweet time, leisurely pedaling or ambling along on a treadmill. Others are hares, impatiently racing through miles at high intensity.
Each approach offers similar health benefits: lower risk of heart disease, protection against Type 2 diabetes, and weight loss.
But new findings suggest that for at least one workout a week it pays to be both tortoise and hare — alternating short bursts of high-intensity exercise with easy-does-it recovery.
Weight watchers, prediabetics and those who simply want to increase their fitness all stand to gain.
This alternating fast-slow technique, called interval training, is hardly new. For decades, serious athletes have used it to improve performance.
But new evidence suggests that a workout with steep peaks and valleys can dramatically improve cardiovascular fitness and raise the body’s potential to burn fat.
Best of all, the benefits become evident in a matter of weeks.
“There’s definitely renewed interest in interval training,” said Ed Coyle, the director of the human performance laboratory at the University of Texas at Austin.
A 2005 study published in the Journal of Applied Physiology found that after just two weeks of interval training, six of the eight college-age men and women doubled their endurance, or the amount of time they could ride a bicycle at moderate intensity before exhaustion.
Eight volunteers in a control group, who did not do any interval training, showed no improvement in endurance.
Researchers at McMaster University in Hamilton, Ontario, had the exercisers sprint for 30 seconds, then either stop or pedal gently for four minutes.
Such a stark improvement in endurance after 15 minutes of intense cycling spread over two weeks was all the more surprising because the volunteers were already reasonably fit. They jogged, biked or did aerobic exercise two to three times a week.
Doing bursts of hard exercise not only improves cardiovascular fitness but also the body’s ability to burn fat, even during low- or moderate-intensity workouts, according to a study published this month, also in the Journal of Applied Physiology. Eight women in their early 20s cycled for 10 sets of four minutes of hard riding, followed by two minutes of rest. Over two weeks, they completed seven interval workouts.
After interval training, the amount of fat burned in an hour of continuous moderate cycling increased by 36 percent, said Jason L. Talanian, the lead author of the study and an exercise scientist at the University of Guelph in Ontario. Cardiovascular fitness — the ability of the heart and lungs to supply oxygen to working muscles — improved by 13 percent.
It didn’t matter how fit the subjects were before. Borderline sedentary subjects and the college athletes had similar increases in fitness and fat burning. “Even when interval training was added on top of other exercise they were doing, they still saw a significant improvement,” Mr. Talanian said.
That said, this was a small study that lacked a control group, so more research would be needed to confirm that interval training was responsible.
Interval training isn’t for everyone. “Pushing your heart rate up very high with intensive interval training can put a strain on the cardiovascular system, provoking a heart attack or stroke in people at risk,” said Walter R. Thompson, professor of exercise science at Georgia State University in Atlanta.
For anyone with heart disease or high blood pressure — or who has joint problems such as arthritis or is older than 60 — experts say to consult a doctor before starting interval training.
Still, anyone in good health might consider doing interval training once or twice a week. Joggers can alternate walking and sprints. Swimmers can complete a couple of fast laps, then four more slowly.
There is no single accepted formula for the ratio between hard work and a moderate pace or resting. In fact, many coaches recommend varying the duration of activity and rest.
But some guidelines apply. The high-intensity phase should be long and strenuous enough that a person is out of breath — typically one to four minutes of exercise at 80 to 85 percent of their maximum heart rate. Recovery periods should not last long enough for their pulse to return to its resting rate.
Also people should remember to adequately warm up before the first interval. Coaches advise that, ideally, people should not do interval work on consecutive days. More than 24 hours between such taxing sessions will allow the body to recover and help them avoid burnout.
What is so special about interval training? One advantage is that it allows exercisers to spend more time doing high-intensity activity than they could in a single sustained effort. “The rest period in interval training gives the body time to remove some of the waste products of working muscles,” said Barry A. Franklin, the director of the cardiac rehabilitation and exercise laboratories at the William Beaumont Hospital in Royal Oak, Mich.
To go hard, the body must use new muscle fibers. Once these recent recruits are trained, they are available to burn fuel even during easy-does-it workouts. “Any form of exercise that recruits new muscle fibers is going to enhance the body’s ability to metabolize carbohydrates and fat,” Dr. Coyle said.
Interval training also stimulates change in mitochondria, where fuel is converted to energy, causing them to burn fat first — even during low- and moderate-intensity workouts, Mr. Talanian said.
Improved fat burning means endurance athletes can go further before tapping into carbohydrate stores. It is also welcome news to anyone trying to lose weight or avoid gaining it.
Unfortunately, many people aren’t active enough to keep muscles healthy. At the sedentary extreme, one result can be what Dr. Coyle calls “metabolic stalling” — carbohydrates in the form of blood glucose and fat particles in the form of triglycerides sit in the blood. That, he suspects, could be a contributing factor to metabolic syndrome, the combination of obesity, insulin resistance, high cholesterol and elevated triglycerides that increases the risk of heart disease and diabetes.
By recruiting new muscle fibers and increasing the body’s ability to use fuel, interval training could potentially lower the risk of metabolic syndrome.
Interval training does amount to hard work, but the sessions can be short. Best of all, a workout that combines tortoise and hare leaves little time for boredom.
A Healthy Mix of Rest and Motion
By PETER JARET
Published: May 3, 2007
SOME gymgoers are tortoises. They prefer to take their sweet time, leisurely pedaling or ambling along on a treadmill. Others are hares, impatiently racing through miles at high intensity.
Each approach offers similar health benefits: lower risk of heart disease, protection against Type 2 diabetes, and weight loss.
But new findings suggest that for at least one workout a week it pays to be both tortoise and hare — alternating short bursts of high-intensity exercise with easy-does-it recovery.
Weight watchers, prediabetics and those who simply want to increase their fitness all stand to gain.
This alternating fast-slow technique, called interval training, is hardly new. For decades, serious athletes have used it to improve performance.
But new evidence suggests that a workout with steep peaks and valleys can dramatically improve cardiovascular fitness and raise the body’s potential to burn fat.
Best of all, the benefits become evident in a matter of weeks.
“There’s definitely renewed interest in interval training,” said Ed Coyle, the director of the human performance laboratory at the University of Texas at Austin.
A 2005 study published in the Journal of Applied Physiology found that after just two weeks of interval training, six of the eight college-age men and women doubled their endurance, or the amount of time they could ride a bicycle at moderate intensity before exhaustion.
Eight volunteers in a control group, who did not do any interval training, showed no improvement in endurance.
Researchers at McMaster University in Hamilton, Ontario, had the exercisers sprint for 30 seconds, then either stop or pedal gently for four minutes.
Such a stark improvement in endurance after 15 minutes of intense cycling spread over two weeks was all the more surprising because the volunteers were already reasonably fit. They jogged, biked or did aerobic exercise two to three times a week.
Doing bursts of hard exercise not only improves cardiovascular fitness but also the body’s ability to burn fat, even during low- or moderate-intensity workouts, according to a study published this month, also in the Journal of Applied Physiology. Eight women in their early 20s cycled for 10 sets of four minutes of hard riding, followed by two minutes of rest. Over two weeks, they completed seven interval workouts.
After interval training, the amount of fat burned in an hour of continuous moderate cycling increased by 36 percent, said Jason L. Talanian, the lead author of the study and an exercise scientist at the University of Guelph in Ontario. Cardiovascular fitness — the ability of the heart and lungs to supply oxygen to working muscles — improved by 13 percent.
It didn’t matter how fit the subjects were before. Borderline sedentary subjects and the college athletes had similar increases in fitness and fat burning. “Even when interval training was added on top of other exercise they were doing, they still saw a significant improvement,” Mr. Talanian said.
That said, this was a small study that lacked a control group, so more research would be needed to confirm that interval training was responsible.
Interval training isn’t for everyone. “Pushing your heart rate up very high with intensive interval training can put a strain on the cardiovascular system, provoking a heart attack or stroke in people at risk,” said Walter R. Thompson, professor of exercise science at Georgia State University in Atlanta.
For anyone with heart disease or high blood pressure — or who has joint problems such as arthritis or is older than 60 — experts say to consult a doctor before starting interval training.
Still, anyone in good health might consider doing interval training once or twice a week. Joggers can alternate walking and sprints. Swimmers can complete a couple of fast laps, then four more slowly.
There is no single accepted formula for the ratio between hard work and a moderate pace or resting. In fact, many coaches recommend varying the duration of activity and rest.
But some guidelines apply. The high-intensity phase should be long and strenuous enough that a person is out of breath — typically one to four minutes of exercise at 80 to 85 percent of their maximum heart rate. Recovery periods should not last long enough for their pulse to return to its resting rate.
Also people should remember to adequately warm up before the first interval. Coaches advise that, ideally, people should not do interval work on consecutive days. More than 24 hours between such taxing sessions will allow the body to recover and help them avoid burnout.
What is so special about interval training? One advantage is that it allows exercisers to spend more time doing high-intensity activity than they could in a single sustained effort. “The rest period in interval training gives the body time to remove some of the waste products of working muscles,” said Barry A. Franklin, the director of the cardiac rehabilitation and exercise laboratories at the William Beaumont Hospital in Royal Oak, Mich.
To go hard, the body must use new muscle fibers. Once these recent recruits are trained, they are available to burn fuel even during easy-does-it workouts. “Any form of exercise that recruits new muscle fibers is going to enhance the body’s ability to metabolize carbohydrates and fat,” Dr. Coyle said.
Interval training also stimulates change in mitochondria, where fuel is converted to energy, causing them to burn fat first — even during low- and moderate-intensity workouts, Mr. Talanian said.
Improved fat burning means endurance athletes can go further before tapping into carbohydrate stores. It is also welcome news to anyone trying to lose weight or avoid gaining it.
Unfortunately, many people aren’t active enough to keep muscles healthy. At the sedentary extreme, one result can be what Dr. Coyle calls “metabolic stalling” — carbohydrates in the form of blood glucose and fat particles in the form of triglycerides sit in the blood. That, he suspects, could be a contributing factor to metabolic syndrome, the combination of obesity, insulin resistance, high cholesterol and elevated triglycerides that increases the risk of heart disease and diabetes.
By recruiting new muscle fibers and increasing the body’s ability to use fuel, interval training could potentially lower the risk of metabolic syndrome.
Interval training does amount to hard work, but the sessions can be short. Best of all, a workout that combines tortoise and hare leaves little time for boredom.
From the NY times article:
It didn’t matter how fit the subjects were before. Borderline sedentary subjects and the college athletes had similar increases in fitness and fat burning. “Even when interval training was added on top of other exercise they were doing, they still saw a significant improvement,” Mr. Talanian said.
Unless they are talking about people who are not on teams, I would think almost all fit college athletes do interval training. If that is the case, the effect they must be seeing has to do with specificity of the exercise. I.e. interval training in one sport must not easily translate into interval training in another.
It didn’t matter how fit the subjects were before. Borderline sedentary subjects and the college athletes had similar increases in fitness and fat burning. “Even when interval training was added on top of other exercise they were doing, they still saw a significant improvement,” Mr. Talanian said.
Unless they are talking about people who are not on teams, I would think almost all fit college athletes do interval training. If that is the case, the effect they must be seeing has to do with specificity of the exercise. I.e. interval training in one sport must not easily translate into interval training in another.
full text of article mentioned by NY Times
This URL...
jap.physiology.org/cgi/content/full/98/6/1985
(Note: you'll need to put the slashes, colon, etc directly in front of it but not the 3 w's -- the system won't let me post a URL because I'm a new user.)
. . . will get you to the free full text of the article mentioned by the NY Times.
At the end of the article, it says "this article has been cited by other articles". There you'll see this article which came out just last month but which was not mentioned in the NY Times article:
Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women
J Appl Physiol, April 1, 2007; 102(4): 1439 - 1447.
Here's the URL to the abstract (again, add the slashes, etc to the front end):
jap.physiology.org/cgi/content/abstract/102/4/1439
Unfortunately, the full text is not free on this one, probably because it's newer. But you'll see from the abstract that this appears to replicate the findings of the 2005 article.[/url]
jap.physiology.org/cgi/content/full/98/6/1985
(Note: you'll need to put the slashes, colon, etc directly in front of it but not the 3 w's -- the system won't let me post a URL because I'm a new user.)
. . . will get you to the free full text of the article mentioned by the NY Times.
At the end of the article, it says "this article has been cited by other articles". There you'll see this article which came out just last month but which was not mentioned in the NY Times article:
Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women
J Appl Physiol, April 1, 2007; 102(4): 1439 - 1447.
Here's the URL to the abstract (again, add the slashes, etc to the front end):
jap.physiology.org/cgi/content/abstract/102/4/1439
Unfortunately, the full text is not free on this one, probably because it's newer. But you'll see from the abstract that this appears to replicate the findings of the 2005 article.[/url]
ET
minor correction
I said that the 2007 article wasn't mentioned in the NY Times article, but it was. (Lead author was Talanian.)
ET