29 replies to this topic

[dumbdumb]

Hi,

I'm not trying to dispute the science behind HIIT, I'm just confused by the difficulties that I'm having with it.

My previous exercise plan was to go to the gym five days a week, hop on the elliptical machine, and keep up a moderate pace at a high resistance and high incline until the machine said I'd burned 500 calories. Keeping this up for a bit over half a year, coupled with a modest revision of my diet, helped me to go from 240 pounds to 190. Then I fell into a blue spell and stopped going and started eating larger meals and desserts again - and gained back to 215, where I have since remained.

I then began HIIT, which I did three times a week (the other two days being weightlifting) and have been on this for just over a month. I have seen only minimal gains in strength, barely noticeable increase in visible tone, a weight loss of only one pound, and no decrease whatever in my waistline. My diet throughout this time has averaged about 1.8k calories per day (and that is a generous estimate.)

It seems like I was losing a whole lot more going the "slow and steady" route than I am going full-tilt. I just don't get it. I'm just as well hydrated as ever, taking more vitamins now than I did before, eating small meals for breakfast and lunch, drinking tons of green and black teas...

I just don't get it. Should I stick with HIIT, or is it possible that some peculiarity of my physiology/biochemistry causes the slow and steady approach to be the more availing in my case?

Thanks!

[tunt01]

They work two different sets of muscles.

HIIT works type 2 muscle fibers, used in burst/strength activity. They use glucose as a main fuel.
Slow/Steady works type 1 muscle fibers, used in endurance activity. They use fat as a main fuel.

If you are not an athlete and just running for weight/health, than typically type 1 activities are you better bet. it will keep your metabolism at a higher level throughout the day also (imo).

[dumbdumb]

They work two different sets of muscles.

HIIT works type 2 muscle fibers, used in burst/strength activity. They use glucose as a main fuel.
Slow/Steady works type 1 muscle fibers, used in endurance activity. They use fat as a main fuel.

If you are not an athlete and just running for weight/health, than typically type 1 activities are you better bet. it will keep your metabolism at a higher level throughout the day also (imo).

Is there any set time at which I ought to stop to prevent the body using protein for fuel?

[yoyo]

HIIT works fine for excercise; of course theres no way to burn as many calories in 20 minutes as you could if you were playing basketball for a couple hours a day. the most important thing for losing weight is just eating less.

[tunt01]

Is there any set time at which I ought to stop to prevent the body using protein for fuel?

Warning: I'm not a certified trainer, doctor, dietician, etc., but I have looked into this dynamic your thread is about. But take my answers with a grain of salt.

With that out of the way here is my advice/response:

- I think the body generally uses protein to repair damage. Most body repair occurs at night, when you are sleeping. This is when your growth hormone is released, this seems to be when your body upregulates BDNF (brain derived neurotrophic factor) for neurogenesis/mind repair. It is why I often avoid all major sources of protein until the last meal before I sleep at night (dinner). This seems to be helping me health-wise, but that is anecdotal feedback. My protein sources tend to be very healthy, a bit of turkey, lentil beans, fish, etc.
- The body internally recycles protein through autophagy when it senses that it is starved for sources of protein externally. This contributes to better organ performance and generally better health. In my opinion, you have to keep your diet short of protein at some point, so your cells are internally recycling bad protein structures (ie. misfolded proteins or the typical causes of Alzheimers, Parkinsons, and other degenerative conditions)
- I think the body generally uses carbs/fats to generate energy (ATP) so that it can perform on the run. Fats obviously exist in a lot of major protein sources.
- I think this is why the healthiest diets I have seen often have as little as 10% protein composition, and your protein in-take should vary based on how much physical damage/stress/exercise you put on your body.
- If you work out for a very long period of time, ie. run for 2 hours than obviously your caloric in-take should increase in response to this workload, even if you are on CR or some kind of specific diet. You have to modify your calories to suit your body's output. If you are sitting on your ass at work/vegging out on TV on the couch, and do nothing all day then obviously your caloric in-take should drop in response and the protein component should be correspondingly small on an absolute and probably even as a % of the total caloric in-take.
- The best data I've seen says that you need to hit 60%-80% of your VO2 Max to be in the Type I fiber twitch performance range. Above 80% you immediately hit glucose/type II muscles and those burn out quickly, like they should in HIIT.

I think the unanswered questions that are posed by your line of thought are:

- Does it make more sense to run 3 times a day for 20 minutes? Or one time a day for 1 hr?
- How much more valuable is running for 1 hour vs. running for 3 hours?
- What is the best for a diabetic? If you are Type II diabetes, maybe it makes sense for you to do HIIT, because it really can improve your glucose uptake/insulin sensitivity. It's often geared to those bodytypes pretty well, because they are husky/chunky-like and have higher muscle mass, which is tilted toward Type II fiber composition and away from Type I. This situation seems to be partially mediated by the hormone imbalance involved in diabetes. It is assumed an average healthy person has equal (50/50) amounts of both (type I, type ii).

I don't know entirely the answers, I'm still sorting it myself. I'm also trying to understand the best TIME of day to exercise. It seems like during the middle of the day is ideal, but it's not practical from a work standpoint for me.


After sifting through some of the data on these issues, I came to the conclusion that I need to try to run 2x a day 2 miles at a 60% VO2 max. Right now I am doing it before and after work. There is a higher number/density of mitochondria in Type I muscle fiber as compared to Type II, and I think it directly correlates to a higher endurance/stamina level which is provided by this muscle type. This is why I am personally focused on that kind of training. I will eventually integrate some mild weight lifting (compound like squats, bench press) for some strength conditioning, but I think movement exercises like throwing a medicine ball are the best ways to handle dealing with strength and agility at the same time... rather than just strength for the sake of bulging muscles. I personally care about functional performance over looks. At least that is my approach...

Edited by prophets, 02 April 2009 - 02:30 PM.

[Shepard]

I then began HIIT, which I did three times a week (the other two days being weightlifting) and have been on this for just over a month.

And there is probably your problem. Can you define how you've been going about HIIT, and what you mean by weightlifting?

[dumbdumb]

For HIIT, I use the elliptical machine (since I've bad knees/ankles and don't want to run on them until I've lost more weight) and warm up for five minutes by going at a moderate pace, on an incline of 6 out of twenty and a resistance of 4 out of twenty. Then I run as fast as I can for twenty seconds, then run for one minute at a speed somewhere between the warm-up speed and the full-run speed. I repeat this eight times, and more than eight times when I feel that I've sufficient energy, or when I don't exercise until late evening and will be going to sleep afterwards. In either case, after the eight or so runs, I cool down for about ten minutes by gradually decreasing the pace, incline and resistance, until my heart rate is at about 135. When running my heart rate is at about 168-170.

For weightlifting I do two sets of twenty repetitions of squats (I think that's what they're called? I put a long bar with weights over my shoulders and then squat down and up) and a similar number of parellel bar dips and pull-ups (both machine-assisted.) I also use a number of isolation machines for the back and abdomen, also at 2x20. I go as slowly as I can manage in all cases, and proceed to the weights immediately after my run on the elliptical (however on the two days of the week that I do both, I only run 6 times rather than 8.)

Edited by dumbdumb, 03 April 2009 - 07:58 AM.

[TianZi]

For HIIT, I use the elliptical machine (since I've bad knees/ankles and don't want to run on them until I've lost more weight) and warm up for five minutes by going at a moderate pace, on an incline of 6 out of twenty and a resistance of 4 out of twenty. Then I run as fast as I can for twenty seconds, then run for one minute at a speed somewhere between the warm-up speed and the full-run speed. I repeat this eight times, and more than eight times when I feel that I've sufficient energy, or when I don't exercise until late evening and will be going to sleep afterwards. In either case, after the eight or so runs, I cool down for about ten minutes by gradually decreasing the pace, incline and resistance, until my heart rate is at about 135. When running my heart rate is at about 168-170.

For weightlifting I do two sets of twenty repetitions of squats (I think that's what they're called? I put a long bar with weights over my shoulders and then squat down and up) and a similar number of parellel bar dips and pull-ups (both machine-assisted.) I also use a number of isolation machines for the back and abdomen, also at 2x20. I go as slowly as I can manage in all cases, and proceed to the weights immediately after my run on the elliptical (however on the two days of the week that I do both, I only run 6 times rather than 8.)

If you are unable to run due to excess body weight, I think you are not ready for HIIT. If you are obese or approaching it, pushing yourself to your limit in bursts (the essence of HIIT) seems like a bad idea--muscle tears, joint injuries, and even a heart attack seem a real possibility.

My advice would be to work up to 30 minutes of some form of cardio at a steadily increasing pace. Then work on slowly increasing your pace over time from workout to workout, rather than settling for the same speed for the same duration each time and simply counting calories. Before you can adopt an arduous exercise regimen that is probably optimal for strength gains and loss of body fat, you must prepare your body for it over time. Prior to the cardio work, do your strength training exercises so as to maximize calorie burn during cardio (and hopefully increase your basal resting metabolic rate). You don't have to hop right on the elliptical trainer or whatever after finishing your last set of weights--take your time and first stretch out (both the muscles you trained lifting weights or otherwise via strength training, and your legs / lower back in preparation for the cardio work), drink some water, etc.

Think outside the box regarding aerobic training. Walking on a steep incline on a treadmill is probably more appropriate for you than running in the short- and mid-term. You can vary the incline and pace to approximate HIIT training if you are determined to do that type of training right now. Walking is much less likely to do damage to your joints, as is walking or running on an incline as opposed to a flat surface. You could also hold light dumbbells and/or ankle weights to make things more difficult. With that said, I think the elliptical trainer is also a fine choice for you at this time.

[Shepard]

I then began HIIT, which I did three times a week (the other two days being weightlifting) and have been on this for just over a month. I have seen only minimal gains in strength, barely noticeable increase in visible tone, a weight loss of only one pound, and no decrease whatever in my waistline.

Sets of 20 reps are way off the spectrum for an appreciable muscular strength adaptation. Cut those back and increase weight and you should see strength gains. But, that will also mean you're doing a good bit of damage to the lower body 5x/week. Not quite good, so you'll have to decide which you want to do more. Strength work and steady state aerobic training is a solid formula for several reasons. Muscular endurance work and interval training don't really make sense from an athletic programming perspective.

[tunt01]

i have no idea about HIIT on an eliptical. i would imagine HIIT in a pool might even be worth trying if you have weight issue.

[imarobot]

They work two different sets of muscles.

HIIT works type 2 muscle fibers, used in burst/strength activity. They use glucose as a main fuel.
Slow/Steady works type 1 muscle fibers, used in endurance activity. They use fat as a main fuel.

If you are not an athlete and just running for weight/health, than typically type 1 activities are you better bet. it will keep your metabolism at a higher level throughout the day also (imo).

I'm not sure about that. A quick check of Wikipedia:

Studies by Tabata[2], Tremblay[3] and others have shown this method to be more effective at burning fat and maintaining, or building, muscle mass than high-volume, lower intensity aerobic work-outs. A study by Gibala et al[4] demonstrated 2.5 hours of sprint interval training produced similar biochemical muscle changes to 10.5 hours of endurance training and similar endurance performance benefits. According to a study by King [5] , HIIT increases the resting metabolic rate (RMR) for the following 24 hours due to excess post-exercise oxygen consumption, and may improve maximal oxygen consumption (VO2 max) more effectively than doing only traditional, long aerobic workouts.[6][7][8][9] Long aerobic workouts have been promoted as the best method to reduce fat, as fatty acid utilization usually occurs after at least 30 minutes of training. HIIT is somewhat counter intuitive in this regard, but has nonetheless been shown to burn fat more effectively. There may be a number of factors that contribute to this, including an increase in RMR, and possibly other physiological effects.

Recently it has been shown that two weeks of HIIT can substantially improve insulin acton in young healthy men. HIIT may therefore represent a viable method for prevention of type-2 diabetes.

10 minutes of HIIT is less punishing on my joints than a 30-minute run. And more muscles seem to be used during HIIT: core muscles sore, sometimes arms.

You might not yet be able to push yourself hard enough for HIIT to work. You should feel a combination of near nausea and exhilaration. It wouldn't be surprising, though, if some people respond to HIIT and some don't, just as some people respond to lifting weights and other people not so much. Do what works. No big deal if HIIT doesn't do it for you, right? A leaner, meaner you could always try it again. Just the fact that you're exercising consistently is enormous.

Something else to try is cut out all wheat and sugar and eat more veggies like broccoli. I accidentally lost 30 lbs (215 to 185 and probably still losing slowly), mostly around my waist, this past year by making a change in diet.

And listen to Shepard.

Edited by imarobot, 03 April 2009 - 05:45 PM.

[TianZi]

As a cautionary tale regarding HIIT, when I tried this for the first time in many years about 2.5 years ago (when I was 37), I tore the hip abductor muscle in my right leg and had to walk with a crutch for almost a week. I'd been trying to do "wind sprints" as I'd been trained to do as a youth.

It took a couple of months to fully recover from that. And I was exercising regularly at the time, but as far as running went, had only been maintaining a steady pace for 30 straight minutes. My body was not ready at age 37 for the leap from a steady 30 minute pace to the fastest sprint I could maintain for a minute. Now, I am able to do this type of training, and do do it twice a week (once bike, once running--my other days I maintain a more constant pace over 30 minutes), but I worked my way carefully up to it.

Beware of advice from well-meaning people based on studies they have read done with people who aren't you, and may be nothing like you. I think HIIT is a terrible thing to recommend to someone who is very out of shape and borderline obese.

[TianZi]

To clarify, I don't know the OP's fitness level or body fat %. He may or may not be an ideal candidate for HIIT training. But it's definitely not a "one size fits all" kind of regimen.

[tunt01]

They work two different sets of muscles.

HIIT works type 2 muscle fibers, used in burst/strength activity. They use glucose as a main fuel.
Slow/Steady works type 1 muscle fibers, used in endurance activity. They use fat as a main fuel.

If you are not an athlete and just running for weight/health, than typically type 1 activities are you better bet. it will keep your metabolism at a higher level throughout the day also (imo).

I'm not sure about that. A quick check of Wikipedia:

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http://en.wikipedia.org/wiki/Muscle

Various exercises require a predominance of certain muscle fiber utilization over another. Aerobic exercise involves long, low levels of exertion in which the muscles are used at well below their maximal contraction strength for long periods of time (the most classic example being the marathon). Aerobic events, which rely primarily on the aerobic (with oxygen) system, use a higher percentage of Type I (or slow-twitch) muscle fibers, consume a mixture of fat, protein and carbohydrates for energy, consume large amounts of oxygen and produce little lactic acid. Anaerobic exercise involves short bursts of higher intensity contractions at a much greater percentage of their maximum contraction strength. Examples of anaerobic exercise include sprinting and weight lifting. The anaerobic energy delivery system uses predominantly Type II or fast-twitch muscle fibers, relies mainly on ATP or glucose for fuel, consumes relatively little oxygen, protein and fat, produces large amounts of lactic acid and can not be sustained for as long a period as aerobic exercise.

HIIT pushes your Type IIa muscles towards fast-twitch. Yes this set of muscles has reasonably high levels of mitochonrdria. Yes your basal metabolism will rise (any exercise will do that). Yes, burst exercises like HIIT will increase your mitochondria content and help remodel those muscles. I'm not saying HIIT is bad, it can be quite good.

But if you are remodeling or reconditioning your cardiovascular system, there is a lot to be said for sustained 60%+ VO2 max aerobic exercise. You are likely remodeling your heart, your fluid balance (sweating) and those gains are more likely made with sustained running rather than sprinting. I'm talking about physiological endurance gains rather than just simply measuring fasting glucose levels. I think there is a lot to be said for HIIT. I may try doing HIIT 2-3 days a week and long runs 3-4 days a week, alternating. But I read a lot of these wide-ranging claims like HIIT is way better than sustained running or you only have to sprint 5x for 30 seconds and that's equivalent to running 2-3 miles and it's just not true. People/scientists take like 2-3 datapoints like glucose or VO2 max changes in 2 groups and just extrapolate to the ends of the earth off a couple datapoints. "We found glucose changes to be better in HIIT, therefore it's better." 1 datapoint doesn't measure a lot of other things that are going on like the aerobic capacity of your heart.

As a cautionary tale regarding HIIT, when I tried this for the first time in many years about 2.5 years ago (when I was 37), I tore the hip abductor muscle in my right leg and had to walk with a crutch for almost a week. I'd been trying to do "wind sprints" as I'd been trained to do as a youth.
...

Beware of advice from well-meaning people based on studies they have read done with people who aren't you, and may be nothing like you. I think HIIT is a terrible thing to recommend to someone who is very out of shape and borderline obese.

I hear a lot of people complain about the impact running has on their bones. Running is a high impact activity, but part of maintaining healthy bones is using them. You can prevent osteo just as easily from running than pretty much any other activity. And your joint health is maintained by keeping proper form and not "pounding the pavement". Run slower and more carefully and focus on control/form. Speedwalk if you have to. I start out walking, do like a quarter - half a mile walk and then run. Your runners high endorphins should help blunt any physical pain/issues.

The reason why people would blow themselves up on HIIT is because they can't maintain good/control form while sprinting and the impact on the joints becomes severe. Also no one in their right mind would go from sedentary/unconditioned to sprinting full out. I don't avoid the gym for 6+ months and then show up one day and try to squat 500 lbs... you have to have some common sense.

Edited by prophets, 04 April 2009 - 11:23 AM.

[imarobot]

I think HIIT is a terrible thing to recommend to someone who is very out of shape and borderline obese.

Dude doesn't sound out of shape or borderline obese. He's 215 and not improving with HIIT. He might be "very out of shape", but because of the level of activity he had before the break, I'd guess he's lost some fitness but not to point where "very out of shape" is a fair description. What do you think, dumbdumb?

Recommending HIIT is like recommending lifting weights. Proper precautions are necessary. I'd never lift without warming up, for instance. And just as prophets mentioned, proper form is important. But HIIT can absolutely be done by someone starting out -- which is not dumbdumb. Like lifting weights, someone trying HIIT should build into a deep routine over weeks or months. But form and warming up and slowly building strength over time are also all applicable for aerobic exericse.

As far as the studies being done on a different type of person -- that might be true. They're often done on athletes whose training or genetics might allow activities us regular people should avoid or practice in smaller doses. Maybe.

Shepard probably has an opinion about all of this. Shepard?

Edited by imarobot, 05 April 2009 - 01:24 AM.

[imarobot]

People/scientists take like 2-3 datapoints like glucose or VO2 max changes in 2 groups and just extrapolate to the ends of the earth off a couple datapoints. "We found glucose changes to be better in HIIT, therefore it's better." 1 datapoint doesn't measure a lot of other things that are going on like the aerobic capacity of your heart.

This is a valid argument. I should wait until more data is in. As TianZi was saying, what works for the subjects of the studies might not work for us regular humans.

Edited by imarobot, 05 April 2009 - 01:35 AM.

[TianZi]

My anecdotal account concerned a muscle tear, not a joint problem. In my case, I was fit when the injury had occurred, and had been running, etc. for over a year on a regular basis. I just hadn't been sprinting.

Since I ran track in high school, it is unlikely the problem was one of form. Rather, it resulted from my body not being prepared for the abrupt transition from running for 30 minutes at a continuous 7:20 second mile pace to sprinting for one minute intervals at a sub-5 minute mile pace. I'd worked myself up to the 7:20 mile pace over the course of a year of training, but sprinting is a very different motion recruiting muscles not used at the slower pace. (By the way, joint pain ceased to be an issue for me over 10 years ago after limiting running to 3 non-consecutive days a week, and supplementing glucosamine--the other days I bike, use the elliptical trainer, or do something else as my cardio routine for the day).

It's simply common sense that a muscle injury, or other injury, is much more likely running, etc. at a very high speed than at a moderate one, particularly for those who are no longer in their teens or twenties (assuming total duration for the run doesn't exceed 30 minutes; running for hours is a totally different animal). What I should have done, and have since done with success, was work up to true "high intensity interval training" by gradually increasing the pace of the sustained motion for the interval over a period of months. I also modified my resistance training by adding hip adductor and hip abductor weight training so as to help avoid the same injury in the future; this also helped me to rehabilitate myself after the serious injury (I'd had an irrational prejudice previously to exercises which focused on the spreading and closing of my legs ) What I've found is that there is only a very limited overlap between the cardiovascular fitness required for 1 - 3 minute intervals and that required for sustained duration aerobic exercises. If I train one and neglect the other, the one I've neglected gets much worse. I therefore do both, and believe my long-term cardiovascular health should benefit in the long run. I liken this to resistance training at the 15 rep vs 10 rep vs 5 rep range, and well-documented limited overlap in progression among these ranges if training is limited generally only to one of them. I'm not sure how the cardiac muscle adapts to different types of training, but for the skeletal muscles used in resistance training, certain fibers are only recruited at certain intensities (Type IIa vs. TypeIIb fibers, for example).

A lot of "theorycrafting" goes on within these forums with very intelligent people extrapolating data & conclusions from isolated studies and then assuming they apply generally sight unseen to all healthy people. On this particular forum, that can quickly lead to injury. This is especially true for exercise regimens that require performance at extreme high intensity to be effective (such as HIIT), or which are highly technical in nature (I cringe when I see people here endorsing snatches and the clean & jerk for the everyman). Frankly, the average guy / gal struggling to become fit is much more likely to thrive under the supervision of the experienced "dumb jock" certified physical trainer at the local gym than by following the online recommendations of , e.g., a bright young PhD candidate writing perched atop an ivory tower.

[nowayout]

..., but sprinting is a very different motion recruiting muscles not used at the slower pace.

Yes, you run a high risk of injury every time you recruit different muscles/tendons/ligaments than what you are used to, and the risk is even higher when you use machines that force you to make unnatural movements. Case in point: I complained to an orthopedist about pain in one knee, and he recommended that I use the elliptical machine instead of the stairmaster. I followed his recommendation, and within two days of very moderate elliptical machine use the damn thing had messed up both my knees and hips badly for three months. I eventually rehabilitated myself (mostly) through running and yes, the embarrassing opening of the legs.

As for HIIT, I find it easier on the joints and tendons than jogging continuously, mostly because my gait seems smoother and with less impact when I run faster. I do a version where I run fast for two minutes and walk for a minute, repeated a few times.

It seems from some studies that HIIT may be better for fat loss and more muscle-sparing than traditional sustained cardio. Since I don't need to lose any weight, I am more interested in whether the cardiovascular benefits are comparable to normal sustained cardio training. Anyone have any studies handy on this issue?

On this particular forum, that can quickly lead to injury.

As on various other forums, especially those dealing with nootropics and supplements. At least with exercise the pain quickly tells you to stop (except for overuse injuries), whereas there the damage is often silent until it is too late.

Edited by andre, 05 April 2009 - 02:04 PM.

[tunt01]

It seems from some studies that HIIT may be better for fat loss and more muscle-sparing than traditional sustained cardio. Since I don't need to lose any weight, I am more interested in whether the cardiovascular benefits are comparable to normal sustained cardio training. Anyone have any studies handy on this issue?

this may seem like a useless response without a study, but i think you need to look at the sustained cardiac output (maybe as measured by blood flow) from the heart in a long endurance run vs. sprint intervals.

you may have better glucose uptake in sprints, and theoretically you should because type-2 muscles rely on glucose more. but remodeling the body for higher total cardiovascular capacity, throughput seems unlikely to me in sprints vs. sustained.

ill try to poke around and find a study later if i have time.

[imarobot]

My anecdotal account concerned a muscle tear, not a joint problem. In my case, I was fit when the injury had occurred, and had been running, etc. for over a year on a regular basis. I just hadn't been sprinting.

It's simply common sense that a muscle injury, or other injury, is much more likely running, etc. at a very high speed than at a moderate one, particularly for those who are no longer in their teens or twenties (assuming total duration for the run doesn't exceed 30 minutes; running for hours is a totally different animal).

A lot of "theorycrafting" goes on within these forums with very intelligent people extrapolating data & conclusions from isolated studies and then assuming they apply generally sight unseen to all healthy people.

Tell me if I'm wrong, but I sense a contradiction here. At the end, you lambast speculation from studies. Yet, you provide anecdotes and "common sense" as support for your argument. As a rule, aren't single-person anecdotes even less worthwhile than small studies? I don't have a problem with anecdotes. I think everyone recognizes them for what they are. But I'm also not the one saying small studies are worthless while providing personal accounts.

I'm just saying that, if you're going to be critical of people instead of the ideas, make sure you're holding yourself to the same standards you expect from others.

Frankly, the average guy / gal struggling to become fit is much more likely to thrive under the supervision of the experienced "dumb jock" certified physical trainer at the local gym than by following the online recommendations of , e.g., a bright young PhD candidate writing perched atop an ivory tower.

So if someone asks for exercise help in these forums, you would say, "Go ask some 'dumb jock' in a gym instead of asking advice from someone who is both a jock and bright." Again, feel free to follow your own advice.

Edited by imarobot, 05 April 2009 - 03:56 PM.

[imarobot]

you may have better glucose uptake in sprints, and theoretically you should because type-2 muscles rely on glucose more. but remodeling the body for higher total cardiovascular capacity, throughput seems unlikely to me in sprints vs. sustained.

That HIIT would benefit VO2 max more than distance running is counter-intuitive. But the studies are pointing at that (see the refs in the Wiki article). I'm curious what you'll find, though. I won't be surprised if Wikipedia isn't the final answer.

As for HIIT, I find it easier on the joints and tendons than jogging continuously, mostly because my gait seems smoother and with less impact when I run faster.

Absolutely. I didn't expect this and thought it was because I wasn't doing enough. But even when I kill myself with HIIT, my joints are fine. No joint discomfort, no drudgery, and the rush of speed -- I'd probably stay with HIIT even if it wasn't as effective as distance.

Edited by imarobot, 05 April 2009 - 04:24 PM.

[TianZi]

My anecdotal account concerned a muscle tear, not a joint problem. In my case, I was fit when the injury had occurred, and had been running, etc. for over a year on a regular basis. I just hadn't been sprinting.

It's simply common sense that a muscle injury, or other injury, is much more likely running, etc. at a very high speed than at a moderate one, particularly for those who are no longer in their teens or twenties (assuming total duration for the run doesn't exceed 30 minutes; running for hours is a totally different animal).

A lot of "theorycrafting" goes on within these forums with very intelligent people extrapolating data & conclusions from isolated studies and then assuming they apply generally sight unseen to all healthy people.

Tell me if I'm wrong, but I sense a contradiction here. At the end, you lambast speculation from studies. Yet, you provide anecdotes and "common sense" as support for your argument. As a rule, aren't single-person anecdotes even less worthwhile than small studies? I don't have a problem with anecdotes. I think everyone recognizes them for what they are. But I'm also not the one saying small studies are worthless while providing personal accounts.

I'm just saying that, if you're going to be critical of people instead of the ideas, make sure you're holding yourself to the same standards you expect from others.

Frankly, the average guy / gal struggling to become fit is much more likely to thrive under the supervision of the experienced "dumb jock" certified physical trainer at the local gym than by following the online recommendations of , e.g., a bright young PhD candidate writing perched atop an ivory tower.

So if someone asks for exercise help in these forums, you would say, "Go ask some 'dumb jock' in a gym instead of asking advice from someone who is both a jock and bright." Again, feel free to follow your own advice.

My anecdotal experience was offered only as proof of what happened to me after eagerly embracing a highly-touted exercise regimen I wasn't ready for. It doesn't contradict my general message that different people are different when it comes to the optimal exercise program for each; rather, it's consistent with that message.

My use of quotation marks around the term "dumb jock" was intentional. The experienced certified PT is experienced in training, and qualified to train, people of varying levels of fitness and varying life circumstances. The internet "expert" (again note the use of quotation marks ) probably is not. The PT is accountable for his/her conduct while doing this. The internet "expert" is not. We have a few posters here who are openly contemptuous and disdainful of certified PT's; my use of quotation marks around the term "dumb jock" was a poke at them.

My point is not that we can't draw reasonable inferences regarding an optimal exercise regimen from looking at a constellation of related studies (versus a single one). Rather, I am trying to encourage people to take the time to consider whether the conclusions reached by such a constellation of studies are likely appropriate as a guideline for modulating their own exercise regimen, after due consideration is given to the size of the pool of participants, and the characteristics of those participants (e.g., all 21 year old males? all trained athletes? etc.) as compared to you. Further, the risk/reward ratio should be considered, in line with your own exercise goals.

We have an advantage when devising an optimal exercise regimen we don't have when trying to formulate the ideal supplement regimen. That difference is that an individual can test the efficacy of a particular exercise or exercise program by doing it for a reasonable period of time and then measuring the demonstrable real world end results. Studies are just a reference source, a possible starting point, with respect to a particular individual. I learned the hard way to be wary of generalized recommendations when it comes to exercise. For me, 2 hand bicep curls with a fixed bar result in elbow tendinitis whereas any biceps exercise that allows my wrist to rotate (such as curls with individual dumbbells or a rope) does not; doing the benchpress the traditional way and touching the bar to my chest trashes my shoulders whereas stopping the downward motion at the point my elbow forms a 90 degree angle does not. Following the advice of others sight unseen, I'd have gotten conflicting advice regarding both exercises, but the feedback from my own body was clear and consistent.

Edited by TianZi, 05 April 2009 - 05:28 PM.

[imarobot]

Caution is smart. And we do have an unfortunate number of people who are snide and openly contemptuous of others. I suspected there was a history behind your remarks. Understood.

[Shepard]

Shepard probably has an opinion about all of this. Shepard?

I'm fine with HIIT as a category of exercise for anyone that allows time for cardiac adaptation to take place. You have to use personal discretion on the type of exercise you choose, though. Most people jog with terrible form, and even more sprint with poor form. Hill sprints are probably better for the average person because they actually require decent form to go anywhere. And, "high intensity" is relative. Outside of exogenous performance enhancers and genetic abnormalities, the average exerciser doesn't have the psychosis required to push the body to serious harm. That said, living comes with a risk. If needed, high intensity aerobic intervals can be used as a bridge to anaerobic intervals.

Edited by Shepard, 05 April 2009 - 05:27 PM.

[tunt01]

That HIIT would benefit VO2 max more than distance running is counter-intuitive. But the studies are pointing at that (see the refs in the Wiki article). I'm curious what you'll find, though. I won't be surprised if Wikipedia isn't the final answer.

HIIT being better for total VO2 max makes sense to me. If you stretch your lungs to max capacity (HIIT) instead of just lumbering along at 60% of VO2 Max (sustained endurance), then it would make sense for HIIT to be the way to increase your total max.

It seems perfectly logical to me. But I think the other benefits of sustained running, their impact on Type 2a and Type I muscles cannot be ignored.

The reality is that 1 type of exercise cannot be the single and only way to health. For anyone (me, you, whoever) to sit there and say this is the single and only way to exercise is foolish. This is why I previously mentioned doing HIIT 2-3 days a week, and doing sustained running 3-4 days a week -- alternating days. There are benefits to both, likely better cardiovascular remodeling and physiological endurance through sustained runing, and better physical capacity/burst capability in HIIT.

[TianZi]

That HIIT would benefit VO2 max more than distance running is counter-intuitive. But the studies are pointing at that (see the refs in the Wiki article). I'm curious what you'll find, though. I won't be surprised if Wikipedia isn't the final answer.

HIIT being better for total VO2 max makes sense to me. If you stretch your lungs to max capacity (HIIT) instead of just lumbering along at 60% of VO2 Max (sustained endurance), then it would make sense for HIIT to be the way to increase your total max.

It seems perfectly logical to me. But I think the other benefits of sustained running, their impact on Type 2a and Type I muscles cannot be ignored.

The reality is that 1 type of exercise cannot be the single and only way to health. For anyone (me, you, whoever) to sit there and say this is the single and only way to exercise is foolish. This is why I previously mentioned doing HIIT 2-3 days a week, and doing sustained running 3-4 days a week -- alternating days. There are benefits to both, likely better cardiovascular remodeling and physiological endurance through sustained runing, and better physical capacity/burst capability in HIIT.

I endorse this based on my own personal experiences.

One more thing: I took a quick glance at some of the more significant HIIT studies out there, and one thing that struck me was that in every one of them, the pool of participants were either "recreationally active males" no older than 21, or highly trained athletes. I saw no studies with a participant pool including anyone who was overweight, and this is relevant to the the OP's inquiry. However, my research was by no means thorough, so If anyone is aware of any HIIT studies that included persons that seem to fit the OP's demographic, you should mention them.

[Cappa]

If you're obese it might be a good idea to do endurance running until you lose enough weight to make HIIT a safer and more viable option.

I started HIIT recently and I'm responding to it amazingly. My metabolism is through the roof. I fall into that "type ii diabetes" group, even though I don't have it (I probably have issues with insulin sensitivity - it seems to run in the family). You'd also want to do HIIT in the morning (although I haven't been as good with this as I'd like).

Edited by Cappa, 30 December 2009 - 04:38 AM.

[mustardseed41]

If you're obese it might be a good idea to do endurance running until you lose enough weight to make HIIT a safer and more viable option.

I started HIIT recently and I'm responding to it amazingly. My metabolism is through the roof. I fall into that "type ii diabetes" group, even though I don't have it (I probably have issues with insulin sensitivity - it seems to run in the family). You'd also want to do HIIT in the morning (although I haven't been as good with this as I'd like).

Why in the morning? Too early for most people. If it's the overnight fasting thing, it makes no big difference in the long haul.

Edited by mustardseed41, 01 January 2010 - 04:59 AM.

[mike250]

so I take it from this discussion that if one is overweight and has poor conditioning he should start with something like sustained walking/incline walking fro say 30 minutes 3 x per week?

[platypus]

the most important thing for losing weight is just eating less.

Gaining more muscle helps a lot too.