“Steady State Cardio 5 X More Effective Than HIIT????”
High Intensity Interval Training, or HIIT for short, has been promoted as one of the most effective training methods ever to come down the pike, both for fat loss and for cardiovascular fitness. One of the most popular claims for HIIT is that it burns “9 times more fat” than conventional (steady state) cardio. This figure was extracted from a study performed by Angelo Tremblay at Laval University in 1994. But what if I told you that HIIT has never been proven to be 9 times more effective than regular cardio… What if I told you that the same study actually shows that HIIT is 5 times less effective than steady state cardio??? Read on and see the proof for yourself.
“There are lies, damned lies, and then there are statistics.”
- Mark Twain
In 1994, a study was published in the scientific journal Metabolism by Angelo Tremblay and his team from the Physical activity sciences laboratory at Laval University in Quebec, Canada. Based on the results of this study, you hear personal trainers across the globe claiming that “HIIT burns 9 times more fat than steady state cardio.” This claim has often been interpreted by the not so scientifically literate public as meaning something like this: If you burned 3 pounds of fat in 15 weeks on steady state cardio, you would now burn 27 pounds of fat in 15 weeks (3 lbs X 9 times better = 27 lbs). Although it’s usually not stated as such, frankly, I think this is what some trainers want you to believe, because the programs that some trainers promote are based on convincing you of the vast superiority of HIIT and the “uselessness” of low intensity exercise. Indeed, higher intensity exercise is more effective and time efficient than lower intensity exercise. The question is, how much more effective? There’s no evidence that the “9 times more fat loss” claim is true outside the specific context in which it was mentioned in this study. In order to get to the bottom of this, you have to read the full text of the research paper and you have to look very closely at the results. 13 men and 14 women age 18 to 32 started the study. They were broken into two groups, a high intensity intermittent training program (HIIT) and a steady state training program which they referred to as endurance training (ET). The ET group completed a 20 week steady state aerobic training program on a cycle ergometer 4 times a week for 30 minutes, later progressing to 5 times per week for 45 minutes. The initial intensity was 60% of maximal heart rate reserve, later increasing to 85%. The HIIT group performed 25-30 minutes of continuous exercise at 70% of maximal heart rate reserve and they also progressively added 35 long and short interval training sessions over a period of 15 weeks. Short work intervals started at 10 then 15 bouts of 15 seconds, increasing to 30 seconds. Long intervals started at 5 bouts of 60 seconds, increasing to 90 seconds. Intensity and duration were progressively increased over the 15 week period.The results: 3 times greater fat loss in the HIIT group
Even though the energy cost of the exercise performed in the ET group was twice as high as the HIIT group, the sum of the skinfolds (which reflects subcutaneous body fat) in the HIIT group was three times lower than the ET group. So where did the “9 times greater fat loss” claim come from? Well, there was a difference in energy cost between groups, so in order to show a comparison of fat loss relative to energy cost, Tremblay wrote,“It appeared reasonable to correct changes in subcutaneous fat for the total cost of training. This was performed by expressing changes in subcutaneous skinfolds per megajoule of energy expended in each program.”
Translation: The subjects did not lose 9 times more body fat, in absolute terms. But hey, 3 times more fat loss? You’ll gladly take that, right? Well hold on, because there’s more.
Did you know that in this oft-quoted study, neither group lost much weight? In fact, if you look at the charts, you can see that the HIIT group lost 0.1 kg (63.9 kg before, 63.8 kg after). Yes, the HIIT group lost a whopping 100 grams of weight in 15 weeks!
The ET group lost 0.5 kilograms (60.6 kg before, 60.1 kg after).
Naturally, lack of weight loss while skinfolds decrease could simply mean that body composition improved (lean mass increased), but I think it’s important to highlight the fact that the research study from which the “9 times more fat” claim was derived did not result in ANY significant weight loss after 15 weeks.
Based on these results, if I wanted to manipulate statistics to promote steady state cardio, I could go around telling people, “Research study says steady state cardio (endurance training) results in 5 times more weight loss than high intensity interval training!” Or the reverse, “Clinical trial proves that high intensity interval training is 5 times less effective than steady state cardio!” Mind you, THIS IS THE SAME STUDY THAT IS MOST OFTEN QUOTED TO SUPPORT HIIT!If I said 5 X greater weight loss with steady state, I would be telling the truth, wouldn’t I? (100 grams of weight loss vs 500 grams?) Of course, that would be misleading because the weight loss was hardly significant in either group, because it doesn’t distinguish between weight loss and body composition and because interval training IS highly effective. I’m simply being a little facetious in order to make a point: Be careful with statistics. I have seen statistical manipulation used many times in other contexts to deceive unsuspecting consumers.
For example, advertisements for a popular fat burner claim that use of their supplement resulted in twice as much fat loss, based on scientific research. The claim was true. Of course, in the ad, they forget to tell you that after six months, the control group lost no weight, while the supplement group lost only 1.0 kilo. Whoop de doo! ONE KILO of weight loss after going through a six month supply of this “miracle fat burner!” But I digress…Back to the HIIT story – there’s even more to it.
In the ET group, there were some funky skinfold and circumference measurements. ALL of the skinfold measurements in the ET group either stayed the same or went down except the calf measurement, which went up.
The girths and skinfold measurements in the limbs went down in the HIIT group, but there wasn’t much difference between HIIT and ET in the trunk skinfolds. These facts are all very easy to miss. I didn’t even notice it myself until exercise physiologist Christian Finn pointed it out to me. Christian said,
“When you look at the changes in the three skinfold measurements taken from the trunk, there wasn’t that much difference between the steady state group (-6.3mm) and the HIIT group (-8.7 mm). So, much of the difference in subcutaneous fat loss between the groups wasn’t because the HIIT group lost more fat, but because the steady state group actually gained fat around the calf muscles. We shouldn’t discount simple measurement error as an explanation for these rather odd results.”
Christian also pointed out that the two test groups were not evenly matched for body composition at the beginning of the study. At the beginning of the study, the starting body fat based on skinfolds in the HIIT group was nearly 20% higher than the ET group. He concluded:“So while this study is interesting, weaknesses in the methods used to track changes in body composition mean that we should treat the results and conclusions with some caution.”
One beneficial aspect of HIIT that most trainers forget to mention is that HIIT may actually suppress your appetite, while steady state cardio might increase appetite. In a study such as this, however, that can skew the results. If energy intake were not controlled, then some of the greater fat loss in the HIIT group could be due to lowered caloric intake. Last but not least, I’d like to highlight the words of the researchers themselves in the conclusion of the paper, which confirms the effectiveness of HIIT, but also helps put it in perspective a bit:“For a given level of energy expenditure, a high intensity training program induces a greater loss of subcutaneous fat compared with a training program of moderate intensity.”
“It is obvious that high intensity exercise cannot be prescribed for individuals at risk for health problems or for obese people who are not used to exercise. In these cases, the most prudent course remains a low intensity exercise program with a progressive increase in duration and frequency of sessions.” In conclusion, my intention in writing this article wasn’t to be controversial, to be a smart-alec or to criticize HIIT. To the contrary, additional research has continued to support the efficacy of HIIT for fat loss and fitness, not to mention that it is one of the most time efficient ways to do cardiovascular training. I have recommended HIIT for years in my Burn The Fat, Feed The Muscle program, using a 1:1 long interval approach, which, while only one of many ways to do HIIT, is probably my personal favorite method. However, I also recommend steady state cardio and even low intensity cardio like walking, when it is appropriate.My intentions for writing this article were four-fold:
1. To encourage you to question where claims come from, especially if they sound too good to be true.
2. To alert you to how advertisers might use research such as this to exaggerate with statistics
3. To encourage the fitness community to swing the pendulum back to center a bit, by not over-selling the benefits of HIIT beyond what can be supported by the scientific research
4. To encourage the fitness community, that even as they praise HIIT, not to condemn lower and moderate intensity forms of cardio.
Tom Venuto
Reference:
Tremblay, Angelo, et al. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. Vol 43. no 7 (July). Pp 814-818. 1994.
Related articles:
Why cardio doesn’t work for some people (members only)
www.burnthefatinnercircle.com/members/440.cfm
Can you really exercise less and lose more weight? (previous blog post)
www.burnthefatblog.com/archives/2007/02/can_you_really_exercise_less_a.php
Recommended resources:
Burn The Fat, Feed The Muscle (Fat Loss “Bible”)
www.BurnTheFat.com
The Facts About Fitness (Bringing Science into fitness)
www.TheFactsAboutFitness.com
12 April, 2008 posted in Science & Research
Comments
I didn't even read the whole thing. Are you pretty much saying that "Steady State Cardio is really Proven 5 X More Effective Than HIIT!" or r u just joking?
I read your ebook and i remember you said HIIT was more effective.
Posted by: Sean | April 12, 2008 2:04 PM
I thoroughly enjoyed this article on the benifits of HIIT or ET training. The way I see it if you do everything in life with balance - not either or - you will benifit. That is eating, sleeping, and training. Too much of anything can do you harm. But doing it in a balanced way is always good for your health.
Posted by: Dan Ormiston | April 12, 2008 3:20 PM
I am glad that you took the time to compare the facts. Many just go with what is written and do not take the time to investigate. It all comes down to what works for you. Some might like one and not like another. You must know the choices available first, then decide which you like best and what works for you.
Posted by: David | April 12, 2008 3:50 PM
The motivation makes a difference in terms of HIIT. For fat loss long slow distance would probably do a better job. HIIT is a training tool for competative athletes. It should not be used to basically reduce fat. All it can do is build muscle mass and speed
Posted by: Robert G Fine | April 12, 2008 4:32 PM
Tom
Thanks so much for laying the cards on the table. I am one of those people that basically gave up "wasting my time" with long moderate intensity workouts because of your Ebook and other fitness advisors' advice that HIIT was the only way to go.
Why? Because I believed the experts knew better then me. I appreciate your honesty.
Laura,
Brougham, Ontario, Canada
Posted by: Laura Stavro | April 12, 2008 5:10 PM
Hey nice article. But when i saw the heading i was bout to kill myself because, i changed from steadys tate to HIIT a few months ago due to a study i saw.
Posted by: Steve Thomas | April 12, 2008 6:14 PM
Steve wrote
" nice article. But when i saw the heading i was bout to kill myself because, i changed from steadys tate to HIIT a few months ago due to a study i saw.
Ok, i stand guilty of attention-mongering with a controversial headline. But it was for a good cause, eh? :-)
Tom
Posted by: tom venuto | April 12, 2008 6:18 PM
Hi Tom,
I am a beginner in the world of fitness, just reading infitisimal amounts of info can be quite confusing. As you pointed out any data can be manipulated depending on a persons agenda. . My approach would be try it an see, each person is unique. If it works for you then do it!! You can't place everybody under the one umbrella and say "this is the only way".
Anything you read you need to test it for yourself and not believe everything that is written!!
Frances
Sydney Australia
Posted by: Frances | April 12, 2008 8:45 PM
I can't think you enough for this article. I am 53 years old and am not trying to lose fat. I just want to enjoy good health. But trying interval syle of training always left me achy and miserable. I love to walk and swim. I am so glad to hear you say that these are effective for good health.
Thanks again.
Susmita
Posted by: Susmita | April 13, 2008 2:15 AM
I had seen this study in other references so I hunted the original down and read it for myself. Dr. Tremblay's intent in his conclusion was never to manipulate the results but simply state the findings. When you read the conclusion Dr. Tremblay makes it quite clear that the energy expended during HIIT was 9 times as great than that of the ET group for the same time period. I was never confused about the results after reading the original.
Cheers - Chris
Dubai
Posted by: Christopher Race | April 13, 2008 2:30 AM
THANK GOD someone can explain the confusing world of weight loss and do it honestly. I've had reconstructive knee surgery about 10 years ago and find it hard to do HIIT as it still makes my knee swell and am forced to do moderate training and have felt so guilty about it for ages. At least I know now that I'm not walking in vain and that I shouldn't feel guilty because I'm still making a difference to my overall body composition
Posted by: Kylie Harcla | April 13, 2008 3:17 AM
Chris wrote:
Dr. Tremblay's intent in his conclusion was never to manipulate the results but simply state the findings.
Oh, goodness! I NEVER implied that it was Doctor tremblay who was manipulating results!
As dr tremblay wrote in the paper "It appeared reasonable to adjust for changes in subcutaenous fat to compare for energy cost".
But of course. Absoultely reasonable to get a good comparison.
No question
Its TRAINERS who are HIIT-centric and anti-aerobics who are manipulating the results!
And, its the non scientifically literate public who are confused by it all and who are misinterpreting and are taking 9 times greater to mean 9 times greater weight loss in pounds of fat
as readers can now see, the HIIT group DID NOT lose more pounds of fat.
regards,
tom venuto
Posted by: tom | April 13, 2008 8:18 AM
I train in both because:
-) low intensity allows me to build up the cardiovascular system (especially increasing lung efficiency)
-) high intensity allows me to move up my lactate treshold limit
Kind regards,
Frank
Posted by: frank | April 13, 2008 8:22 AM
All these studies are pretty much meaningless. I would like to see a study of people who all eat 6 clean meals a day. No processed food, no HFCS, no trans fat, and an all natural/organic diet. Until, then these studies are just for pure amusement, which I don't mind. When you're in the "know", you really can't do much else except sit back and laugh. Why worry about the last 5% when your not worrying about the first 95%.
Anyway, Tom is the best!
Posted by: anthony in hoboken | April 13, 2008 11:08 AM
Anthony, thanks for your post. In one sense you could say research like this is "meaningless" in terms of it being fat loss research in free living humans where they did not control diet. AND, in fact you could reasonably extend that to ALL fat loss research in free living humans where diet is not controlled because people underestimate their food intake so much, its not even funny... ESPECIALLY the folks who are NOT eating clean and measuring food etc... the folks who eat inconsistently, and who eat a restraurants and a lot of fast food, i dare say they underestimate the worst of all... so this fact renders many results from fat loss studies, as you said, somewhat meaningless if you consider it from that point of view
on the other hand, we have to give our obesity researchers a lot of credit for doing this kind of work when you consider just how difficult it is to control these studies. We really can learn a lot from the research - if we dont have science then we dont have anything but one persons word against another. Our own experience is great, but we fool ourselves and jump to inappropriate conclusions there as well - even if we have the body to show for it and we are "in the know." We may know that WHAT we did worked for us, but truth is, we dont really know WHY it worked. Science gives us the WHY.
the research is valuable, we just have to be careful not to jump to cause and effect conclusions from correlational research (epidemilogy) and we have to be careful making conclusions from experimental weight loss research in free living humans when diet is not controlled, and as I mentioned in this article, we have to be careful with statistics!
Over time, if the research is continuously and courageously pursued, the old errors are corrected and the truth comes out.
best regards,
tom v.
Posted by: Tom | April 13, 2008 11:27 AM
Hi Tom. I have believed this all along. I will never be a long distance runner but just a steady jog of 20 min twice a day has been far more beneficial to me than doing it any other way. Everyone said I was wasting my time doing it "steady state" but I have been seeing a slow but steady decrease in my weight. Love your newsletters Glenda
Posted by: Glenda | April 13, 2008 2:24 PM
Dear Tom,
I have been training fitness clients for 27 years in my CA based studio. I just read your info and could not agree with you more. I have implemented both types of cardio training and found one thing to be true in every client situation;
Burning fat is only effective when all factors are considered;
Age level
nutrition
Amount of intensity
duration
Possible modality of client ( all ability levels should be considered)
Type of training induced, circuit, cardio split, interval and split circuits (we could go on and on choosing specific sequences of training types)
Any auto immune negatives etc...
I think establishing a clients fitness baseline in both body fat, lean muscle, water hydration and over all baseline of health and total assessment levels are to be considered!
I have enjoyed getting your fitness letters and you are very "right on" in your thinking and I for one very much appreciate your" out of the box" thinking!
keep the awesome sharing of great information!
Sincerely yours in great health!
Michael
Posted by: Michael | April 13, 2008 2:29 PM
But I thought you recommended HIIT in the BFFM handbook? Was I wrong? Did I read that wrong in the handbook? Tell me where it is so I can go and reread.
Thank you
Karen
Posted by: Karen | April 13, 2008 6:58 PM
karen
I recommend all kinds of burning of calories! That was my point!
you certrainly read correctly I recommended HIIT as well as steady state cardio in my book. both burn calories.
The more intensely you exercise, the more calories you burn. Simple right? But does that mean you should never do low intensity or moderate intensity exercise, or that low intensity exercise is "worthless" or a "waste of time?" Of course not!
The debates about HIIT versus steady state were getting out of hand, and that was the reason for the article. Some HIIT proponents say that since HIIT burns more calories, then lower intensity cardio is useless or should never be done - That is totally untrue. HIIT is not appropriate for beginners or people with certain conditions, and low intensity cardio works fine for lots of people, it just doesnt burn as many calories, so it takes more of it (less time efficient)
The article was my attempt at knocking some "sense" back
into some people, if you know what I mean - getting the pendulum to swing back to center...
The headline was satirical...spoof.. (although actually true if you twist the statistics a certain way). You had to read the whole article and understand the current debate I suppose for it all to make sense.
Its all very simple:
Just Keep burning those calories, however you like to exercise, do it. If you are short on time and you are healthy, do at least some of your cardio (2-3 sessions per week) as HIIT.
best regards,
tom v
Posted by: tom venuto | April 13, 2008 7:03 PM
Reading through the comments, its clear to see that many people have read the title of this post, and went straight to post a comment...
Anyway, good post Tom, and thanks for the straight up approach as always.
Trevor.
Posted by: Trevor | April 13, 2008 10:09 PM
Great article and what I have been telling many clients and friends for ages. There is no right or wrong way to do cardio.
They all have a place. In my own training I perform one long steady pace cardio run (50 mins) at around 75% of max HR.
I also do one long optional easy cardio per week, 30-40 mins of cycling or even walking, closer to 65%
I do 2 HIIT sessions using sprints -
Plus 1 Intensity run (running at threshold for 20 minutes)
That is a sample of my my six days of cardio
So I don't fall into any "my category is better than yours", just get out there and do it!
Posted by: Nick Zografos | April 14, 2008 12:50 AM
It's so tempting to take research at face value, even when you have been trained in scientific research as I have. If you are going to change your lifestyle based on the results of a study, it's definitely worthwhile to read HOW they conducted the study, not just what they concluded.
Unfortunately it requires that much extra time and effort, and our brains like to cut to the chase!
Posted by: Lady G | April 14, 2008 4:24 AM
In my opinion, it really doesnt matter that much you use either HIIT or ET. The real problem when you want to lose body fat is keeping your motivation high. And the latter can only be reached when you ENJOY the process of losing fat: you enjoy the exercise you do (HIIT or ET), you enjoy how good you feel after it, you enjoy feeling healthier and more attractive and so on.
I haven’t read whole BFFM yet (I started a couple of days ago) but one thing is clear about this program to me: its about changing your life to a healthier and better one. You cant do that with a type of exercise you don’t enjoy, cos your motivation will fail over time and all that fat will eventually come back.
Enjoy the process of losing fat as much as you enjoy the results of losing fat. The rest will come by itself, at a steady rate, if we understand the knowledge Tom has given to us.
Posted by: Eduardo | April 14, 2008 6:14 AM
hi,
Nicely put together article - Tom good job as usual.
Regards,
Sumeet
Posted by: Sumeet | April 14, 2008 6:24 AM
Tom -
It has always interested me how research can be swayed to believe whatever you want to believe. Fitness Professionals, at least the ones who continue to keep up with research, know what is real and what is crap.
For all of you looking to lose weight, tone up, build muscle, listen to Tom's advice. He, and others like him, have done all the guesswork for you to help you reach your goals as quick as possible and as safely as possible. The amount of misinformation out there is mind-boggling. When reading information from the newspapers, tv, magazines, be weary of the source, especially is the research is sponsored by the company promoting the product.
Tom - you give our industry a huge pat on the back that is needed every now and then. Keep up the good work. I look forward to the newsletter. Your headline piqued by interest and I was glad to read that is was a spoof.
Dave Radin, CSCS, NASM-CPT
Posted by: Dave in Charlotte | April 14, 2008 7:22 AM
Thanks for the info tom,..... very much....
I've read your e-books... and thank you for all the great info and knowledge in these blog/email updates...
Yin and yang~
Posted by: OhShi | April 14, 2008 9:22 AM
This was an interesting article. Obviously, in terms of weight/fat loss, ET may be more effective. However, if you are training for a marathon, triathlon, or other competitive sports, ET will not inprove your VO2max near as well as HITT. It just depends on your goal. If you simply want to lose fat, then ET is better. If you want to increase your cardiorespiratory endurance, then HITT is the only way to train. I have found that alternating between the two is optimal. For example, I will perform HITT training for 45-60 minutes 3 days per week, and perform ET for 45-60 minutes 3 days per week. The ET days serve almost as a recovery period for the HITT days. I typically only push myself to 50-60% MHR (slow jog) on ET days. On HITT days, I push as hard as I can. Just experiment and see if it works.
Posted by: James Delongchamp, 2LT, U.S. Army | April 14, 2008 11:53 AM
HIIT or LISS? ??
How 'bout Crossfit!
Posted by: aram | April 14, 2008 11:55 AM
Tom,
Fantastic write-up. Lately I've been bombarded with HITT stuff myself and while I do enjoy those type of workouts, I mix them up with longer duration, moderate intensity cardio.
This is probably one of your best articles in my opinion.
Marc C David
"The NoBull Muscle Guy"
Posted by: Marc David | April 14, 2008 12:55 PM
I read recently that HIIT training on a cycle will assist in fat loss in the lower extremities and HIIT training while walking or jogging (walk or jog/sprint) will help with abdomin fat. What do you think?
Posted by: Alan Kittner | April 15, 2008 1:27 AM
One thing that is completely ignored in the HIIT versus steady cardio debate are the relative psychological effects. In very general terms whereas steady cardio has often a calming, meditative effect. Interval training is often perceived as stressful, as all the focus is on the clock/stopwatch. Not everyone is happy with having more stress in their lives. However, for some people steady cardio is simply too boring.
Posted by: Silke Sheppard | April 15, 2008 4:42 AM
Excellent point. Compliance to the exercise program is what will ultimately prove a program a success or failure in the long term. You have to choose an activity you enjoy.
If HIIT is far more effective in terms of calories burned, that doesnt help if someone cant or wont stick with a HIIT program. But if they love to walk, even if if the walikng only burns half the calories and therefore takes twice as long to get the desired results, in the long run, the walking would win
Many people use the word BORING in every sentence to describe long duration low intensity, steady state cardio, but boring is not a fact, boring is someones value judgement/opinion.
let me use the low carb analogy. Low carb will beat high carb in the short term every time, not just water weight either, but check back after a year and the advantages are usually lost in comparison with high carb, or balanced diets, so in the end, the best diet, as with exercise, provided you have a caloric deficit, will be dictated very much on ones personal preference and ability to comply with the program.
regards,
tom v.
Posted by: tom venuto | April 15, 2008 8:05 AM
Some excellent points have been made.
HIIT has been my only method of training for years. When I worked as a personal trainer, I advocated it to most of my clients - even the "newbies".
Intensity is relative. A person new to exercise can work at higher levels of intensity. But they may only be able to do it for ten seconds.
After all, many overweight people find climbing a flight of stairs to be high-intensity.
I've come to appreciate that many people just don't like to work "balls to the wall" for any period of time. HIIT could be the greatest way in the world to burn fat - but it will only work if it's done with consistency.
If a person, say my wife, won't can't stand high-intensity exercise, it's no good at all.
Just my .02.
Posted by: Curtis Penner | April 15, 2008 10:47 PM
EXCELLENT EXCELLENT article!!! :)
Ok... this might sound strange, but this article was SO good, that this is the FIRST time ever, that I'm posting on a fitness related forum. Over the years, I've seen tons of articles on various topics that keep "peddling" something or the other... and have led me to be extremely skeptical of almost anything I see online. I've been receiving Tom's newsletter for a while now, and after my initial skepticism, I started liking his articles more and more. The main reason:
- Tom's articles promote one thing : KNOWLEDGE!!
I truly believe this is the hardest thing to acquire in today's fitness industry. I'm 34, have 2 engineering degrees, an MBA from Northwestern, and am semi-retired. Not bragging... just establishing credentials. I quit the corporate world to do something that I have always been passionate about, and that was to help people w/ their health and fitness (recently got certified as a PT). The one thing that constantly amazes me is the number of people (including many "professionals") who tout things based on "studies" and "reports"... but who have no idea about the what/where of the study itself! Tom is the only author I've seen who presents all the relevant information and asks the reader to make a judgment based on facts... not opinions or interpretations.
Thank you Tom! Even more so because it takes a huge effort to be able to keep up your free newsletters AND to respond to individual comments personally. Just wanted to let you know that I appreciate what you do for so many people ... although most people don't see the amount of work that goes into what you do. :)
Posted by: Hari R. | April 16, 2008 12:11 PM
Curtis wrote
Intensity is relative. A person new to exercise can work at higher levels of intensity. But they may only be able to do it for ten seconds.
I can agree completely - intensity is relative, and beginers could do interval training, safety permitting. But is it really true high intenisty interval training? If you prescribe interval training to a beginner, is the intensity high enough to produce the post-workout adaptations that are so touted from the resarch as the primary benefit of HIIT over SS?
see the laforgia paper:(Effects of exercise intensity and duration on the excess post-exercise oxygen consumption, Journal of sports science, 2006, 24:12, 1247-1264)
bold emphasis mine
"the earlier research optimism regarding an important role for the EPOC in weight loss is generally unfounded. This is further reinforced by acknowledging that the exercise stimuli required to promote a prolonged EPOC are unlikely to be tolerated by non-athletic individuals.
tom
Posted by: tom venuto | April 16, 2008 3:29 PM
Tom,
Why hasn't there been an 8-week study where variables are controlled? If you have a study group of X number of individuals, you could even control calories and macronutrient breakdown on a bodyweight or LBM vs fat % ratio? So, a heavier, mroe muscles person would consume more calories and more of each specific macronutrient than that of a smaller person? It seems feasible to me, and in fact, I think a large amount of people would sign up to participate in this study. Thoughts?
Posted by: Bryan | April 25, 2008 5:09 PM
Tom,
One more comment, after reading these posts: You say multiple times that HIIT burns more calories. I need to digress on this. I always thought that the reason HIIT was so effective for fat loss was because it sorta confused the body, and the afterburn effect was much greater, but I never believed it burns more calories DURING the session. When I do HIIT, I alternate 4.5 walk on the treadmill, with 11.0 run. I go 1 minute of each for 10 "cycles" (20 minutes). THis averages out to 7.75 speed for 20 minutes. If I were to run steady state, I could easily run at an 8.5 for over 20 minutes, and that would essentially burn more calories. Am I wrong here?
Posted by: Bryan | April 25, 2008 5:14 PM
Bryan.
(1) weight loss studies are difficult to do because it is difficult to control food intake in free living humans. people cheat on their diets. You would literlly have to lock them in a research ward and feed them lab/hospital served food to control the intake. U want to sign up, LOL? underreporting of food intake in free living humans is that bad. Even if they tried, they wouldnt get it right. In one study, lean dieticians underreported food intake by 16%. most people underreport 30-40% or MORE
(2) Higher intensity exercise burns more calories per unit of time. not just HIIT per se... high intensity even higher intensity steady state. If the intensity is high enough, then there is the additional caloric expenditure from EPOC
Posted by: Tom | April 25, 2008 5:27 PM
If you pay for my food for 8 weeks, and Im getting atleast 250g of protein, I will gladly sign up to be locked up and have my food intake controlled lol
Strange you say people under-report... well actually, not strange, I believe it, but personally, I always OVER-estimate, so that Im probably taking in less calories than I report in my journal. For example, a 6 inch sub roll, grocery store bought, with no nutrition facts, I call 62 carbs, and 8g of protein and 2g of fat, just to be on the safe side, and in reality, it probably has more like 50 carbs and 5g of protein..
Posted by: Bryan | April 25, 2008 5:43 PM