HIIT most effective "outside comfort zone"

Preparation, Preparedness & Prevention Fitness and Nutrition
1

Bit of a “no duh” article on HIIT, but it’s nice to see it’s getting attention on the main stream media at least. They do make a point I have made many time, many people who think they are doing HIIT are not. Two, Interval training is not worthless, but it’s not HIIT technically. HIIT, for the time spent, will be more effective, all things being equal. But, like anything that has more benefits, it takes a higher level of effort and commitment, is not for everyone, and has higher risk of OTS, injury, etc. As always, risk/benefit assessment applies as well as goals, etc. LISS also has it’s potential value as active rest, etc. Personally, I prefer to do HIIT on a stair stepper or similar machine as it’s non impactive and easy to speed up and slow down fast as HIIT requires.

Key to High Intensity Interval Training found outside comfort zone

With High Intensity Interval Training (HIIT), which consists of short bursts of intensive activity followed by short periods of recovery, fitness experts say the harder the push, the greater the reward.

HIIT can blast calories, build muscle and boost endurance with impressive efficiency in just 20 minutes a day, but the catch is finding the right level of intensity outside the comfort zone, fitness trainers say.

Sean Bartram, author of the book “High Intensity Interval Training for Women,” said to find that level people should think about what it is like being chased by a rabid dog.

“It’s just below that,” he said. “To gain maximum benefits you have to push your body to a place that’s almost uncomfortable.”

The American College of Sports Medicine predicts HIIT will be a top fitness trend in 2015. Bartram said people are drawn to it for its efficiency and almost endless variety of exercises.

The bursts can be sprinting or spot jumps and the recovery can be rests or slower paced movements, he explained.

“You could alternate 30 seconds of sprinting with 30 seconds of walking, or you could engage in a series of bodyweight exercises, such as push-ups, doing each for 30 seconds with 10 seconds of rest in between,” he said.

[b]Dr. Michele Olson, a professor of exercise science at Auburn University at Montgomery, Alabama, said it’s not high intensity unless the heart rate is elevated to near 90-plus percentage of its maximum.

“Many people think they are engaging in HIIT but they are really doing traditional interval training, where the heart rate is around 75 to 85 percent of max,” she said.[/b]

Maximum heart rate is about 220 minus age, according to the American Heart Association.

Olson said that if done properly, HIIT can increase the effectiveness in losing abdominal fat and prompt favorable changes in cholesterol and insulin levels.

“There is research showing that you can cut your exercise time nearly in half,” she said.

About 20 minutes of HIIT can reap similar benefits of doing 35 to 40 minutes of moderate, steady-state cardio, she added, noting the training level must be intense.

Hayley Zawadzki, personal training manager at New York Health and Racquet Club fitness centers, suggests that anyone starting HIIT should have a fitness analysis.

“If you have a history of high blood pressure or medications, you cannot push to the absolute max,” she said.

http://www.reuters.com/article/2015/02/02/us-fitness-hiit-idUSKBN0L617E20150202

2

Any idea what happens physiologically when the 90% HR threshold is exceeded to cause the purported benefits? Also what’s the ideal interval? There’s a biiiig difference between 30 on 30 off and 30 on 10 off.

3

On a cellular level? HIIT is almost a perfect blend of the metabolic adaptations of resistance training and aerobics/conditioning work. This not the most recent review, so there’s likely additional effects on various pathways looked at since, but:

“High-intensity interval training (HIT) induces skeletal muscle metabolic and performance adaptations that resemble traditional endurance training despite a low total exercise volume. Most HIT studies have employed ‘all out’, variable-load exercise interventions (e.g. repeated Wingate tests) that may not be safe, practical and/or well tolerated by certain individuals. Our purpose was to determine the performance, metabolic and molecular adaptations to a more practical model of low-volume HIT. Seven men (21 ± 0.4 years, inline image ml kg−1 min−1) performed six training sessions over 2 weeks. Each session consisted of 8–12 × 60 s intervals at ∼100% of peak power output elicited during a ramp inline image peak test (355 ± 10 W) separated by 75 s of recovery. Training increased exercise capacity, as assessed by significant improvements on both 50 kJ and 750 kJ cycling time trials (P < 0.05 for both). Skeletal muscle (vastus lateralis) biopsy samples obtained before and after training revealed increased maximal activity of citrate synthase (CS) and cytochrome c oxidase (COX) as well as total protein content of CS, COX subunits II and IV, and the mitochondrial transcription factor A (Tfam) (P < 0.05 for all). Nuclear abundance of peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) was ∼25% higher after training (P < 0.05), but total PGC-1α protein content remained unchanged. Total SIRT1 content, a proposed activator of PGC-1α and mitochondrial biogenesis, was increased by ∼56% following training (P < 0.05). Training also increased resting muscle glycogen and total GLUT4 protein content (both P < 0.05). This study demonstrates that a practical model of low volume HIT is a potent stimulus for increasing skeletal muscle mitochondrial capacity and improving exercise performance. The results also suggest that increases in SIRT1, nuclear PGC-1α, and Tfam may be involved in coordinating mitochondrial adaptations in response to HIT in human skeletal muscle.”

http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2009.181743/abstract

I don’t think there’s an ideal interval per se. There seems to be a number of variations, from perhaps the toughest, such as the Tabata protocol, named after Dr Tabata, who published research on HIIT:

5 minutes of warm-up
8 intervals of 20 seconds all-out intensity exercise followed by 10 seconds of rest
2 minutes cool-down

That was done on elite athletes and it’s not for beginners to HIIT that’s for sure. Longest 4 minutes of your life…

Essentially a maximal “all out” effort for 20-30 seconds (as no one can sustain an all out effort past that) followed by a rest time, and repeated. That will depend on the conditioning level of the person. I have done 30:30 X 10 on a stair stepper and thought I might die. But it sure is done fast! For some people, as little 3 minutes total of HIIT will improve their conditioning.

Personally, I go through phases with HIIT as it’s easy for me to over train doing it.

4

So if I currently do 160+ minutes a week of steady-state cardio keeping my HR in the 80-85% range, how long per week would I need to do HIIT to get relatively equal cardio training?

As far as the HR goes, are they talking about the whole 20 minutes being at 90% or is that what it should be spiking to during the exercises?

5

I’ll take HIIT over jogging any day of the week. I despise jogging and though it is good for you, less the impact damage to the knees, I still hate it.

I’ve seen some of my best performance gains in training over the past few months with increased amounts of HIIT thrown in with other interval-type training, and of course resistance training.

We do a ton of Tabatas as well, usually as a finishing exercise to completely burn out the focal muscle group or to really push our core. Let me tell you, a 4 minute Tabata of mountain climbers and plank jacks will burn your core to shreds after a 40 minute interval workout with some heavier weights mixed in. I’ve had many a days of fighting to keep my pre-workout shake down lol

Tapatalk’d

6

I will do 5 minutes of HIIT as a warm-up to my regular lift days, and a 20 minute HIIT day as an active rest day on my days off. It is great stuff but god does it make you want to drop dead.

7

HIIT, true HIIT, is about as far as you can get from active rest. Active rest for a day off, is a 20-40 minute walk, some laps in a pool, yoga, that type of thing. HIIT, not so much. HIIT should be seen as a workout day, and treated as such as it demands a high level of recoup similar to resistance training. As far as your body and CNS is concerned, you’re essentially training 7 days per week. OTS and or injury is in your future.

8

I have incorporated HIIT into my weekly training routine, specifically on leg day (usually some sort of plyometrics / burpee / jump squat combo while wearing a PC or weight of some sort). I get my high-rate up to 95% during this time (I wear a hear rate monitor) and try to maintain it for at least 20 minutes.

I find that take 30-60 second break in between sets (but still moving; ie running in place) provides enough of a break to allow me to go 20 minutes without quitting.

9

I may do HIIT once a week as part of a whole body conditioning day for something different. Something like 30:30 on a stair stepper type machine for 10 mins, followed by some sort of whole body circuit/interval that hits the major parts, and maybe a 10 min cool down on treadmill and some mobility work/stretching.

10

I’ve been doing a type of HIIT for at least 10 years: once a week, 15 minutes on stationary bike, with 3 gradually lengthening sprints. During the last sprint, I’ll get within 98% of max HR (according to the official formula). The workout hasn’t really changed over the years, in fact it’s on the same bikes in the same gym since we moved our office in 2003 (corporate gym). I just get older and keep going. Guess I should retire this workout when I fall off the bike?

11

I’m more into the alternative HR formulas. The Karvonen method basically uses the difference between your resting and max under the logic that the more fit you become the lower your resting will get, thus the HRR or heart rate reserve gives a better idea of where you should be.

The other point I would mention to anyone doing HR training is that as your hydration level changes, so does your HR. So after 15 min on a bike, then intervals or increasing length, some of that increase you may see can be due to hydration. I prefer to run intervals starting with longer ones and progressing to shorter but speeding up with each progression. Example:

2x 3/4 mile (1200m) at 6:39 pace

2x 1/2 mile (800m) at 6:21 pace

2x 1/4 mile (400m) at 6:15 pace

1/4 mile recoveries in between at 7:53 pace

12

Sounds like bag work with kicks would be a good fit for this type of training. I’m going to give this a shot at at the end of my current training cycle. Will: thanks for the info!

13

I have 3 off days. First is static and dynamic stretching, second HIIT, third is static and dynamic stretching again. I wont always do HIIT on my second off day though. HIIT days consist of 5-10 minute warm-up on a row machine at an 8 setting keeping over 30 rows/min and then circuits with 2 upper body exercises, 2 lower, and 2 ab/core with walking or jump rope during rest period, finishing off with static stretching.

14

How many days in a row could HIIT training be done? How many times per week if not done in a row. I have done the Tabata stuff, whew!