HIIT, overrated or the optimal form of exercise? BrinkZone Radio covers that topic!

[WillBrink]

BRINKZONE RADIO COVERS HIIT TRAINING!

Brink Zone Radio – High Intensity Interval Training (HIIT), overrated or the optimal form of exercise?

HIIT training has become very popular recently, but what is HIIT training? Who will benefit from it? What’s the difference between HIIT and interval training? Is it superior to aerobics? In this show we answer those and many other questions about HIIT training with researcher Dr. Abbie Smith-Ryan.

Go HERE to listen to the show!

[misanthropist]

Listened to this yesterday. Great interview. I wondered a bit about the relationship between HIIT and Tabata sprint protocols. I also wondered a little about Tacfit and whether practitioners of Tacfit would be likely to get similar benefits.

Thanks for making this information available. I love having access to serious information in a field which is so often dominated by hyperbole and broscience.

Sent from my SGH-I317M using Tapatalk 2

[WillBrink]

Listened to this yesterday. Great interview. I wondered a bit about the relationship between HIIT and Tabata sprint protocols.

Tabata protocol is HIIT in it's purest form really, but many are not in the condition to do them. One can do HIIT various ways (as Dr. Smith-Ryan explains) and Tabata is but one way to do it. Tabata kicks my butt.

For those not familiar, the Tabata protocol is so named due to Izumi Tabata, the researcher who came up with it and was done with well trained athletes.

The Tabata Protocol goes like so:

5 minutes of warm-up

8 intervals of 20 seconds all-out intensity exercise followed by 10 seconds of rest

2 minutes cool-down

The HIIT session I did the other day was 30 seconds all out with 1 min off done for 10 cycles or 30:60X10

I also wondered a little about Tacfit and whether practitioners of Tacfit would be likely to get similar benefits.

That one is more apples and oranges, but there's a lot of good info and programming with TacFit. It's more an overall fitness program one could add some HIIT specific training to if they wanted.

Thanks for making this information available. I love having access to serious information in a field which is so often dominated by hyperbole and broscience.

I'm glad you enjoyed the show! Here's how I feel about the broscience:

[misanthropist]

I definitely agree with that t-shirt.

The reason I mentioned Tacfit is that it is structured in 20s on, 10s off sets x 8 reps per exercise. I don't think Tacfit is quite the same all-out intensity as HIIT but I'm not certain about that. Maybe some people would get that level of effort?

Sent from my SGH-I317M using Tapatalk 2

[WillBrink]

I definitely agree with that t-shirt.

The reason I mentioned Tacfit is that it is structured in 20s on, 10s off sets x 8 reps per exercise. I don't think Tacfit is quite the same all-out intensity as HIIT but I'm not certain about that. Maybe some people would get that level of effort?

Got it. TacFit is not going to be HIIT as it's not an all out effort. However, TacFit also has programming that has different components to it and some components can have a high level of difficulty which may get your HRM above the minimum 80% or above needed for the effects of HIIT.

Ergo, if some components/training modules of TacFit are high intensity and short duration, and in cycles, they may indeed be HIIT.

That's all HIIT is technically which is why it can be applied in so many ways.

[misanthropist]

So would you say that the benefits of HIIT are primarily cardiovascular?

IIRC you mentioned in the interview that there were possible muscular benefits to HIIT (I can't swear to the exact phrasing) but that this was less well understood. It made me wonder if there was research regarding any specifics of, say, hypertrophy during bouts of HIIT vs the same exercises performed conventionally.

After seeing you mention Tacfit (here or elsewhere, I don't remember) I looked in to it a little and thought the premise looked pretty interesting and my sense was that a really advanced level of programming seemed to be taking place in the evolution of the exercises, but what I was less sure about was if there was a specific advantage to the 20/10x8 scheduling, and if there would be a sort of interval-training spinoff benefit, whether that was somehow anabolic or cardiovascular or what.

I have been a big believer in the Tabata sprint for a couple of years...when I do it I pretty much have to start with the expectation of puking at the side of the local high school track for a while but I credit a program of that and compound lifts a la Starting Strength for my performance in training evos like SouthNarc's ECQC stuff...the Tabata stuff is brutal but it sure seems to help my body to work well under extreme duress.

Anyway I sure appreciate you taking the time to elaborate on this...I'm a big fan of your work.

[WillBrink]

So would you say that the benefits of HIIT are primarily cardiovascular?

More than cardio for sure, as well as improved V02Max and metabolic adaptations that won't be seen with LISS.

IIRC you mentioned in the interview that there were possible muscular benefits to HIIT (I can't swear to the exact phrasing) but that this was less well understood. It made me wonder if there was research regarding any specifics of, say, hypertrophy during bouts of HIIT vs the same exercises performed conventionally.

Possible yes, which came as a surprise to me also. Her lab found the HIIT protocol actually superior to some resistance training protocols for LBM. That was really interesting finding I thought. What resistance protocols, on who, etc, we didn't get to, but something I have to look into by reading the studies from her lab.

I have been replacing typical leg day with HIIT every other leg day using the protocol above it seems like a good mix so far. I'd do a few cycles of sprints after some leg workouts in the past, and other stuff (prowler sled push, etc) but that simple HIIT program of 30:60X10 followed by some core work (planks, stir the pot, etc) and foam rolling and stretching, and done. Quick, effective, difficult, and if her results apply to me, possible + to leg development and performance.

After seeing you mention Tacfit (here or elsewhere, I don't remember) I looked in to it a little and thought the premise looked pretty interesting and my sense was that a really advanced level of programming seemed to be taking place in the evolution of the exercises, but what I was less sure about was if there was a specific advantage to the 20/10x8 scheduling, and if there would be a sort of interval-training spinoff benefit, whether that was somehow anabolic or cardiovascular or what.

Or similar to the effects of other cross training type training, a decent blend of strength and cardio fitness. I doubt one is going to get any major anabolic/LBM building effects from TatFit, but that's no the goal of the program.

I have been a big believer in the Tabata sprint for a couple of years...when I do it I pretty much have to start with the expectation of puking at the side of the local high school track for a while but I credit a program of that and compound lifts a la Starting Strength for my performance in training evos like SouthNarc's ECQC stuff...the Tabata stuff is brutal but it sure seems to help my body to work well under extreme duress.

Anyway I sure appreciate you taking the time to elaborate on this...I'm a big fan of your work.

Tabata was done on highly conditioned athletes and I'd say recommended for people already in a high level of conditioning. There's also various ways to do HIIT that's not Tabata and longer times between the "all out" portion may have some advantages.

Experiment with different protocols with 60 secs probably being the longest time between "sets" you'd want to go as it's long enough to restore ATP/PCR but not so long your heart rate drops much.

For me, the 30:60 ratio seems to work well without killing me.

Per the show, using a heart rate monitor might be the optimal approach as it will allow you to really dial in the HIIT, but not needed per se for experienced and conditioned people per se.

Those new to it, would really benefit from using a monitor.

[5cary]

More than cardio for sure, as well as improved V02Max and metabolic adaptations that won't be seen with LISS.

By "metabolic adaptations", are you referring to what some call the "afterburn"? Or is that a different subject? One of the reason's I got into HIIT was the increase in metabolic rate it generated throughout the day (allegedly). May I ask your opinions on this? TIA.

[WillBrink]

By "metabolic adaptations", are you referring to what some call the "afterburn"? Or is that a different subject? One of the reason's I got into HIIT was the increase in metabolic rate it generated throughout the day (allegedly). May I ask your opinions on this? TIA.

The scientific term for the afterburn effect is Excess post-exercise oxygen consumption (EPOC) and HIIT will have superior EPOC to say LISS for sure. However, the metabolic adaptations are more extensive then that. Here's some granular info on some of the metabolic effects, at least as it applies to fat loss:


HIGH-INTENSITY INTERVAL TRAINING:
THE OPTIMAL PROTOCOL FOR FAT LOSS?

By James Krieger

As exercise intensity increases, the proportion of fat utilized as an energy substrate decreases, while the proportion of carbohydrates utilized increases (5). The rate of fatty acid mobilization from adipose tissue also declines with increasing exercise intensity (5). This had led to the common recommendation that low- to moderate-intensity, long duration endurance exercise is the most beneficial for fat loss (15). However, this belief does not take into consideration what happens during the post-exercise recovery period; total daily energy expenditure is more important for fat loss than the predominant fuel utilized during exercise (5). This is supported by research showing no significant difference in body fat loss between high-intensity and low-intensity submaximal, continuous exercise when total energy expenditure per exercise session is equated (2,7,9). Research by Hickson et al (11) further supports the notion that the predominant fuel substrate used during exercise does not play a role in fat loss; rats engaged in a high-intensity sprint training protocol achieved significant reductions in body fat, despite the fact that sprint training relies almost completely on carbohydrates as a fuel source.

Some research suggests that high-intensity exercise is more beneficial for fat loss than low- and moderate-intensity exercise (3,18,23,24). Pacheco-Sanchez et al (18) found a more pronounced fat loss in rats that exercised at a high intensity as compared to rats that exercised at a low intensity, despite both groups performing an equivalent amount of work. Bryner et al (3) found a significant loss in body fat in a group that exercised at a high intensity of 80-90% of maximum heart rate, while no significant change in body fat was found in the lower intensity group which exercised at 60-70% of maximum heart rate; no significant difference in total work existed between groups. An epidemiological study (24) found that individuals who regularly engaged in high-intensity exercise had lower skinfold thicknesses and waist-to-hip ratios (WHRs) than individuals who participated in exercise of lower intensities. After a covariance analysis was performed to remove the effect of total energy expenditure on skinfolds and WHRs, a significant difference remained between people who performed high-intensity exercise and people who performed lower-intensity exercise.

Tremblay et al (23) performed the most notable study which demonstrates that high-intensity exercise, specifically intermittent, supramaximal exercise, is the most optimal for fat loss. Subjects engaged in either an endurance training (ET) program for 20 weeks or a high-intensity intermittent-training (HIIT) program for 15 weeks. The mean estimated energy cost of the ET protocol was 120.4 MJ, while the mean estimated energy cost of the HIIT protocol was 57.9 MJ. The decrease in six subcutaneous skinfolds tended to be greater in the HIIT group than the ET group, despite the dramatically lower energy cost of training. When expressed on a per MJ basis, the HIIT group’s reduction in skinfolds was nine times greater than the ET group.

A number of explanations exist for the greater amounts of fat loss achieved by HIIT. First, a large body of evidence shows that high-intensity protocols, notably intermittent protocols, result in significantly greater post-exercise energy expenditure and fat utilization than low- or moderate-intensity protocols (1,4,8,14,19,21,25). Other research has found significantly elevated blood free-fatty-acid (FFA) concentrations or increased utilization of fat during recovery from resistance training (which is a form of HIIT) (16,17). Rasmussen et al (20) found higher exercise intensity resulted in greater acetyl-CoA carboxylase (ACC) inactivation, which would result in greater FFA oxidation after exercise since ACC is an inhibitor of FFA oxidation. Tremblay et al (23) found HIIT to significantly increase muscle 3-hydroxyacyl coenzyme A dehydrogenase activity (a marker of the activity of b oxidation) over ET. Finally, a number of studies have found high-intensity exercise to suppress appetite more than lower intensities (6,12,13,22) and reduce saturated fat intake (3).

Overall, the evidence suggests that HIIT is the most efficient method for achieving fat loss. However, HIIT carries a greater risk of injury and is physically and psychologically demanding (10), making low- and moderate-intensity, continuous exercise the best choice for individuals that are unmotivated or contraindicated for high-intensity exercise.

[Ironman8]

I have been a big believer in the Tabata sprint for a couple of years...when I do it I pretty much have to start with the expectation of puking at the side of the local high school track for a while but I credit a program of that and compound lifts a la Starting Strength for my performance in training evos like SouthNarc's ECQC stuff...the Tabata stuff is brutal but it sure seems to help my body to work well under extreme duress.

Can you elaborate on the benefits that you've seen by doing these things? Specifically the higher performance under stress?

I've been doing "higher" intensity intervals, but have been focusing more on overall endurance as of late....as in being able to run multiple miles vs. short distance sprints. Once I get my endurance levels up to where I think they should be, I want to incorporate more "all out sprint" work to my regimen. So that's why I'm curious...plus I have an ECQC in a month