Today, we've got a special guest post from Michael Boyle ofStrengthCoach.com. This is some fantastic stuff - definitely one of the most comprehensive articles I've seen on the topic of interval training
Interval Training- HIIT or Miss?
I think every fat loss article we read espouses the value of interval training for fat loss. In fact the term HIIT (for High Intensity Interval Training) is thrown around so much that many people just assume they know what it is. However, among all the recommendations I see to perform HIIT, very few articles contain any practical information as to what to do or how to do it. I have to confess that I stumbled into this area somewhat accidentally. Two different processes converged to make me understand that I might be a fat loss expert and not know it. In my normal process of professional reading I read both Alwyn Cosgrove's Afterburn and Craig Ballantyne's Turbulence Training. What struck me immediately was that what these experts were recommending for fat loss looked remarkably like the programs we used for conditioning.
At the time I was reading these programs, I was also training members of the U.S. Women's Olympic Ice Hockey team. It seemed all of the female athletes I worked with attempted to use steady state cardio work as a weight loss or weight maintenance vehicle. I was diametrically opposed to this idea as I felt that steady state cardiovascular work undermined the strength and power work we were doing in the weight room. My policy became "intervals only" if you wanted to do extra work. I did not do this as a fat loss strategy but rather as a "slowness prevention" strategy. However, a funny thing happened. The female athletes that we prevented from doing steady state cardiovascular work also began to get remarkably leaner. I was not bright enough to put two and two together until I read the above-mentioned manuals and realized that I was doing exactly what the fat loss experts recommended. We were on a vigorous strength program and we were doing lots of intervals.
With that said, the focus of this article will be not "why," as we have already heard the "why" over and over, but "how." How do I actually perform HIIT? To begin, we need to understand exactly what interval training is? In the simplest sense, interval training is nothing more than a method of exercise that uses alternating periods of work and rest. The complicated part of interval training may be figuring out how to use it. How much work do I do? How hard should I do it? How long should I rest before I do it again?
Interval training has been around for decades. However, only recently have fitness enthusiasts around the world been awakened to the value. The recent popularity of interval training has even given it a new name in the literature. Interval training is often referred to as High Intensity Interval Training (HIIT), and it is now the darling of the fat loss and conditioning worlds. Truth is, you can also do low intensity interval training. In fact most people should not start with HIIT but LIIT. HIIT may make you vomit if you don't work into it.
In case you have been in a cave for the last decade let's quickly review some research. A recent study, done in Canada at McMaster University and often referenced as the Gibala Study after lead researcher Martin Gibala, compared 20 minutes of high intensity interval training, consisting of a 30 second sprint followed by a four minute rest, with 90 to 120 minutes in the target heart rate zone. The result was amazing. Subjects got the same improvement in oxygen utilization from both programs. What is more amazing is that the 20 minute program only requires about two minutes and 30 seconds of actual work.
A second study that has become known as the Tabata study again shows the extreme benefits of interval training. Tabata compared moderate intensity endurance training at about 70 percent of VO2 max to high intensity intervals done at 170 percent of VO2 max. Tabata used a unique protocol of 20 seconds work to 10 seconds rest done in seven to eight bouts. This was basically a series of 20 second intervals performed during a four-minute span. Again, the results were nothing short of amazing. The 20/10 protocol improved the VO2 max and the anaerobic capabilities more than the steady state program.
Further evidence for the superiority of higher intensity work can be found in the September/October 2006 issue of the ACSM Journal. Dr. David Swain stated "running burns twice as many calories as walking." This is great news for those who want to lose body fat. I am not a running advocate, but we can put to rest another high intensity (running) versus low intensity (walking) debate.
Do the math. Swain states that a 136-pound person walking will burn 50 cal/mile and proportionally more as the subject's weight increases. In other words, a 163-pound person would weigh 20 percent more and, as a result, burn 20 percent more calories. This means that expenditure goes from 50 to 60 calories, also a 20 percent increase. Swain goes on to state that running at seven mph burns twice as many calories as walking at four mph. This means a runner would burn 100 calories in roughly eight and one half minutes or about 11 calories a minute. The walker at four miles per hour would burn 50 calories in 15 minutes (the time it would take to walk a mile at four MPH). That's less than four calories per minute of exercise. Please understand that this is less a testament for running and more a testament for high intensity work versus low intensity work. More intensity equals greater expenditure per minute.
Interval Training Methods
There are two primary ways to performing interval training. The first is the conventional Work-to-Rest method. This is the tried and true method most people are familiar with. The Work-to-Rest method uses a set time interval for the work period and a set time interval for the rest period. Ratios are determined, and the athlete or client rests for generally one, two or three times the length of the work interval before repeating the next bout. The big drawback to the Work to Rest method is that time is arbitrary. We have no idea what is actually happening inside the body. We simply guess. In fact, for many years, we have always guessed, as we had no other "measuring stick."
Heart Rate Method
With the mass production of low cost heart rate monitors, we are no longer required to guess. The future of interval training lies with accurate, low cost heart rate monitors. We are no longer looking at time as a measure of recovery, as we formerly did in our work-to-rest ratios. We are now looking at physiology. What is important to understand is that heart rate and intensity are closely related. Although heart rate is not a direct and flawless measure of either intensity or recovery status, it is far better than simply choosing a time interval to rest. To use the heart rate method, simply choose an appropriate recovery heart rate. In our case, we use 60 percent of theoretical max heart rate. After a work interval of a predetermined time or distance is completed, the recovery is simply set by the time it takes to return to the recovery heart rate. When using HR response, the whole picture changes. Initial recovery in well-conditioned athletes and clients is often rapid and shorter than initially thought. In fact, rest to work ratios may be less than 1-1 in the initial few intervals. An example of a sample workout using the heart rate method for a well-conditioned athlete or client is show below.
Interval 1 - Work 60 sec rest 45 sec
Interval 2 - Work 60 sec rest 60 sec
Interval 3 - Work 60 sec rest 75 sec
Interval 4 - Work 60 sec rest 90 sec
*In a conventional 2-1, time based program the rest period would have been too long for the first three intervals, rendering them potentially less effective. The reverse may be true in a de-conditioned athlete or client. I have seen young, de-conditioned athletes need rest up to eight times as long as the work interval. In fact, we have seen athletes who need two minutes rest after a 15 second interval. In the heartrate method the rest times gradually get longer. Th first interval is 1-.75 while the last interval is 1 to 1.5,
The Problem with Formulas
At least 70 percent of the population does not fit into our age-old theoretical formulas. The 220 minus age formula is flawed on two key points: it doesn't fit a significant portion of the population, and it is not based on research. Even the developer of the now-famous formula admits that his thoughts were taken out of context. The more accurate method is called the Heart Rate Reserve Method or Karvonen formula.
(Max HR- Resting HR) x %+ RHR= THR
Ex- (200-60) x.8 +60 = 172
The key to the Karvonen formula is that it looks at larger measures of fitness by incorporating the resting heart rate and is therefore less arbitrary. However, the two twenty minus age formula will suffice for establishing recovery heart rates.
Interval Training Basics
The longer the interval, the shorter the rest period as a percentage of the interval. In other words, short intervals have a high muscular demand and will require longer rests when viewed as a percentage of the interval. Fifteen second intervals will need at least a 2-1 rest to work ration. Three to one will work better for beginners.
Interval Rest Recommendations (Work-to-Rest Based)
- 15 sec. Beginners at least 45 sec (3-1), more advanced 30 sec (2-1)
- 30 sec. Rest 1:00 to 1:30 (3-1 or 2-1)
- 1:00. Rest 1:00- 2:00 (2-1 or 1-1)
Just remember, as the intervals get longer, the recovery time, as it relates to the interval, may not need to be as long. In other words, a fifteen second sprint may require 30-45 seconds rest but a two minute interval may only need to be followed by a two minute rest.
The biggest benefit of interval training is that you can get a tremendous aerobic workout without the boredom of long steady state bouts of exercises. In fact as the Gibala study demonstrated, you can get superior benefits for both fitness and fat loss by incorporating interval training. If the heart rate is maintained above the theoretical 60 percent threshold proposed for aerobic training, then the entire session is both aerobic and anaerobic. This is why my athletes do almost no "conventional" aerobic training. All of our aerobic work is a by-product of our anaerobic work. My athletes or clients can get their heart rate in the recommended aerobic range for 15 to 20 minutes, yet in some cases, they do only three to five minutes of actual work.
Modes of Interval Training
Although most people visualize interval training as a track and field concept, our preferred method of interval training is the stationary bike. Although I think running is the theoretical "best" mode of training, the facts are clear. Most Americans are not fit enough to run. In fact, statistics estimate that 60 percent of those who begin a running program will be injured. In a fitness or personal training setting, that is entirely unacceptable. Females, based on the genetics of the female body (wider hips, narrower knees) are at potentially even greater risk. Physical therapist Diane Lee says it best in her statement, "You can't run to get fit. You need to be fit to run."
Interval training can be done on any piece of equipment. However, the most expeditious choice in my opinion will be a dual action bike like theSchwinn AirDyne. The bike allows, in the words of performance enhancement expert Alwyn Cosgrove, "maximum metabolic disturbance with minimal muscular disruption." In other words, you can work really hard and not injure yourself on a stationary bike.
Fit individuals can choose any mode they like. However, the bike is the best and safest choice. In my mind, the worst choice might be the elliptical trainers. Charles Staley, another noted training expert, has a concept I believe he calls the 180 Principle. Staley advocates doing exactly the opposite of what you see everyone else in the gym doing. I'm in agreement. Walking on a treadmill and using an elliptical trainer seem to be the two most popular modes of training in a gym. My conclusion, supported by Staley's 180 Principle, is that neither is of much use.
Interval Training Modes in DetailRunning
Maybe the most effective method but also most likely to cause injury.
Shuttle runs (running to a line and back repeatedly) have both high muscular demand (acceleration and deceleration) and high metabolic demand.
Running is relative. Running straight ahead for 30 seconds is significantly easier than a 30 second shuttle.
Shuttle runs produce more muscular discomfort due to the repeated acceleration and deceleration.
Running for the average gym-goers is impractical as a fairly large area is needed.
A close second to ground based running in both effectiveness and unfortunately injury potential.
Getting on and off a moving treadmill is an athletic skill and can result in serious injury. Therefore, treadmill interval running is probably not for the average personal training client.
Treadmill speeds are deceiving. For example, 10 MPH is only a six minute mile yet can feel very fast. However, 10 MPH is not a difficult pace for intervals for a well-conditioned athlete.
High quality interval treadmills should be able to go to 15 MPH.
For treadmill running, first practice the skill of getting on and off the moving treadmill (The author assumes no responsibility for those thrown on the floor attempting this. Do not try this in a normal health club, where the treadmills are packed in like sardines. You must have room to fall off without striking an immovable object).
Additional Treadmill Drawbacks
Lack of true active hip extension may under train the hamstrings.
In treadmill running, the belt moves, you just stay airborne. Treadmill times do not translate well to running on the ground. This may be due to lack of ground contact time.
Time based. Try 15 seconds on with 45 seconds off at 7 MPH and 5% incline. For safety, decrease speed and increase incline.
Heart rate based (max HR of 200 used for example). Try a 15 second sprint at 7/5 and simply rest until the heart rate returns to 120 beats per minute. Rest is rest, don't walk or jog or your heart rate will lower slowly.
Dual action bikes like the Airdyne produce a higher HR. This is due to the combined action of the arms and legs. There is no better affordable option than the AirDyne. Although they require periodic maintenance they are the perfect interval tool as they do not need any adjustments to belts or knobs when interval training. The fan is an accommodating resistance device. This means that the harder you push the more resistance you get back. If you have large fan AirDyne, purchase and install windscreens. Most athletes and clients dislike the large fan AirDynes as they are unable to work up a sweat without a windscreen.
This is probably the best "safe" tool.
Requires limited skill.
Limited potential for overuse injury.
Stationary Bike Recommendations
Same time recommendations as for the treadmill. For the AirDyne, set the top display to Level. For a well-conditioned male a 15 second sprint should be level 12-15. Do not go all out as this will seriously undermine the ability to repeat additional intervals. Well-conditioned female athletes will be Level 8-10 for 15 seconds. Levels should be adjusted down for fitness level and up for body size. Larger athletes or clients will find the bike easier. Large fan AirDynes (older models) will have slightly different work levels than the newer smaller fan models.
Slideboards provide the best "bang for the buck" after the AirDyne. However, in a fitness setting there is a skill requirement. Clients must be warned that they may fall and potentially be injured. This may sound stupid but be sure to inform the client that the board is slippery. I can't tell you how many clients have stepped on a slideboard and remarked "this is slippery". Remember what they say about assuming.
The slideboard provides added the benefits of a standing position and getting hip ab and adductor work.
Slideboards are also great for groups. No adjustment are needed, you just need extra booties. We order 4 pair for every board.
Safe in spite of "experts." Some so-called experts have questioned the effect of the slideboard on the knees; however, there is nothing more than the anecdotal evidence of a few writers to support this theory.
Climbers and Ellipticals
The key to using any climbing device is to keep the hands and arms off of the equipment. This is critical. Just put a heart rate monitor on and keep the hands of and watch the heart rate skyrocket. If clients complain about lack of balance, slow down the machine and develop the balance, but don't allow them to hold on.
The StepMill is the least popular, and as Staley points out, the most effective. Think 180 again. If it's popular, it's probably not good.
Conventional Stairclimbers are easier to abuse than the StepMill. Many users ramp up the speed while allowing the arms to do the majority of the work. As we mentioned before, keep your hands off the rails.
The elliptical machine is most popular because it is easiest. This is nothing more than human nature at work. Discourage your clients from using an elliptical trainer. If they insist, let them do it on their off days.
Research continues to mount that interval training may improve fitness better than steady state work. The big key is not what to do any more but, how to do it. For maximum effect, get a heart rate monitor and go to work.
One warning. Deconditioned clients may need three weeks to a month of steady work to get ready to do intervals. This is OK. Don't kill a beginner with interval training. Begin with a quality strength program and some steady state cardiovascular work. The only good use for steady state work in my mind is preparing an athlete or client for the intervals to come.
Resistance Exercise Reverses Aging in Human Skeletal Muscle." Simon Melov, Mark Tarnopolsky, Kenneth Beckman, Krysta Felkey and Alan Hubbard PLoS ONE 2(5): e465. doi:10.1371/journal.pone.
"Short Term Sprint Interval Versus Traditional Endurance Training: Similar Initial Adaptations in Human Skeletal Muscle and Exercise Performance Journal of Physiology Sept 2006, Vol 575 Issue 3.
Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Tabata I, Nishimura K, Kouzaki M, Hirai Y, Ogita F, Miyachi M, Yamamoto K. Department of Physiology and Biomechanics, National Institute of Fitness and Sports, Kagoshima Prefecture, Japan.
September/October ACSM Health and Fitness Journal. Dr. David Swain Moderate or Vigorous Intensity Exercise: What Should We Prescribe?
Michael is a Boston-based strength and conditioning coach and the editor of StrengthCoach.com. You can purchase Mike's products through Perform Better. The above article is based on the best-selling Interval Training DVD filmed in 2007.
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1. Last weekend, my girlfriend and I headed down to Florida for a quick three-day escape to warm weather, but today, we'll be shooting up to Southern Maine to visit with my mother's class. She's a teacher at my old stomping grounds, Kennebunk High School (Go Rams). I'll be chatting with her students about fascinating topics such as:
a. how to make a fried egg without a spatula
b. how I became a ninja without ever receiving a degree in ninjalogy from an accredited institution
c. why Tony Gentilcore's knee sleeves smell worse than...well...anything
d. why they should wear belts and stop turning the brims of their baseball caps off to the side
2. I had a new article published yesterday at T-Nation: Seven Habits of Highly Defective Benchers
In reality, this article could have been called "Why Kevin Larrabee has missed a 300-pound bench press 931 times."
And, a second attempt, just because the first one was sooooo close...
Don't worry, Larrabee; you're still my boy.
3. Speaking of writing, I actually got started on a new project this week. Things quiet down a bit for me during the high school baseball season, so it is when I focus more on seminars, writing, and rescuing kittens from trees.
4. This week's 16x16 sled relay went a lot more smoothly than last week. In fact, we beat our best time by about 45 seconds. We've got one more week of this madness, and then we'll find something new for the Thursday insanity.
5. Just a quick note of congratulations to the Lincoln-Sudbury hockey team, whose season came to an end with a tough loss in the state semifinals last night. Nine guys from the team trained with us last off-season, and these guys deserved all the success that came their way. Nice job this season, fellas.
In my line of work, I get to see a lot of pitching instructors and hitting coaches. Some have the unbelievable ability to really get through to kids and make them great. On the other hand, there are some that flat-out suck.
As I've seen these two ends of the spectrum, I've come to realize that the best guy to teach you a curveball is rarely the one who has had a dirty 12-to-6 breaking ball since he was in seventh grade. Rather, the guy that can teach you the most is the one who struggled with his curveball for years and tried everything to even turn it into a mediocre pitch.
Here's your weekly Maximum Strength success story:
"Just finished the Maximum Strength program and it was awesome! I played college volleyball and and after letting myself get out of shape, I started weight training about 2 years ago. Obviously playing volleyball you could probably guess I have bad knees. Bedsides the typical tendinitis and jumpers knee, I also had a lateral release done on each knee. I never really squatted since I thought it was bad for my knee's, but one of the guys at the gym who is involved in powerlifting got me squatting. Then I found your book and everything in it seemed to line up with the way I was thinking about working out, and I can tell you my knee's feel better now than they ever have in my life.
"I'm kicking myself for not doing all the energy workouts, but still stoked with the results. It's been about six weeks since I completed the program and I am already thinking of doing Maximum Strength again.
"Thanks for the great book and looking forward to the next one.
36 (37 in April)
Body weight: 216 (13.1% body fat)
Broad jump: 98 inches.
Box Squat: 365 lbs.
Bench Press: 255 lbs.
Deadlift: 365 lbs.
3 Rep Chin-up: 254 lbs.
Body weight: 226 (14.1% body fat)
Broad jump: 110 inches.
Box Squat: 395 lbs. (just missed 405, didn't get the depth)
Bench Press: 275 lbs
3 rep Chin-lup: 268 pounds
It's been established pretty clearly that gluteal amnesia - or insufficient recruitment of the glutes - is a contributing factor to lower back and knee pain. Fortunately, lots of people have gotten their act together and worked to get it firing correctly via both dynamic flexibility and activation drills and specific cuing during resistance training movements.
Unfortunately, the overwhelming majority of these drills have focused strictly on activating the glutes in the sagittal plane (divides the body into left and right sides). In the process, a lot of folks have overlooked the fact the the glutes are actually active in three planes of motion. As you can tell from points of attachment in the picture below, the line of pull of the glutes also allow it to abduct and externally rotate the hip.
With this functional anatomy in mind, I think it's very important for coaches and trainers to implement more multi-planar movements in warm-ups. For more information on the what, why, and how, check out the Building the Efficient Athlete DVD Set.
Let me be clear about one thing: with the possible exception of anything that comes out of Larry King's mouth, there are no unimportant interview questions. Every question or comment serves a purpose, whether it's to get the interviewee to open up, show emotion, unleash new information, or just get back on track. Everything matters.
But I recently learned that sometimes I should just let the guy ramble. If he wants to rant, my job is to shut up and make sure the tape recorder keeps rolling.
Most of the guys I interview are great at going off on tangents. And while the resulting transcript is often a jumbled mess of opinion, applied research, and hard-earned experience, occasionally I get something unexpected: an idea for a completely different article based on the unrelated information or opinion. To paraphrase Rod Stewart, every tangent tells a story.
This is a collection of those tangents and tidbits from Dave Tate, Chris Bathke, Matt McGorry, Eric Cressey, and Craig Weller.
Q: Recently, I've noticed that I've lost a lot of mobility/flexibility that means I can't squat with my hands close in and with a high bar like I used to, I now have to go low bar and hands almost at the collars. What stretches/mobility work would you recommend to remedy this problem? I don't think this situation's very good for my shoulder health.
A: It's a common problem, and while the solution is pretty simple, it takes a dedicated effort to regular flexibility and soft tissue work. And, you're right that it isn't very good for shoulder health; that low-bar position can really wreak havoc on the long head of the biceps.
For starters, it's important to address thoracic spine mobility. If you're rounded over at the upper back, it'll be impossible to get the bar in the right "rack" position - regardless of what's going on with the shoulder itself. The first thing I do with folks in these situations is check to make sure that they aren't doing any sit-ups or crunches, which shorten the rectus abdominus and depress the rib cage, causing a more "hunchback" posture.
After you've eliminated these exercises from their programming, you can get to work on their thoracic spine mobility with drills from Optimal Shoulder Performance; one example would be thoracic extensions on the foam roller.
As you work to regain that mobility, it's valuable to build stability within that newly acquired range-of-motion (ROM) with loads of horizontal pulling (rows) and deadlift variations.
With respect to the shoulder itself, it's important to regain lost external rotation ROM and scapular posterior tilt. As I recently wrote in "The Right Way to Stretch the Pecs," I prefer the 1-arm doorway pec stretch and supine pec minor stretches. You can find videos of both HERE - and you can expedite the process with regular foam rolling on the pecs.
In the interim, substitute front squats, overhead squats, single-leg exercises, and deadlift variations to maintain a training effect.
As you progress back to squatting, you can ease the stress on your shoulders by going with a pinky-less grip in the short-term.
That said, for many individuals, the back squat set-up may not be appropriate. These include overhead throwing athletes, those with flexion-based back pain (e.g., disc herniations), and individuals with posterior labral tears.
I'd estimate that only about 25% of Cressey Performance clients do a true back squat, but that's influenced considerably by the fact that we deal with a ton of baseball players, and I get a lot of shoulder corrective exercise cases. Instead, we do a lot of work with the giant cambered bar and safety squat bar, in addition to front squatting.
Hopefully, these recommendations get you headed in the right direction and back to squatting as soon as possible!
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1. There were no Random Friday Thoughts last week, as my girlfriend and I were in Fort Lauderdale for a quick 3-day "the guys are off to spring training, so Eric is going to regain his sanity" vacation. As you read this, I'll have just returned to Boston (Sunday night), refreshed and ready to go for the last three weeks before the high school baseball season starts.
2. With almost all the guys done for the off-season, I figured that this was as good a time as any to send out some spring training well wishes to all the Cressey Performance pro baseball guys:
Chad Rodgers (Braves)
Will Inman (Padres)
Tim Collins (Blue Jays)
Tim Stronach (Mets)
Shawn Haviland (A's)
Nate Nelson (Blue Jays)
Steffan Wilson (Brewers)
Steve Hammond (Giants)
CJ Retherford (White Sox)
PJ Zocchi (Indians)
Matt Morizio (Royals)
Ryan Reid (Rays)
Matt Kramer (Braves)
Dave Wasylak (Nationals)
Jason Lavorgna (free agent)
Matt Cooney (free agent)
Chris Gusha (free agent)
Good luck this season, fellas. Thanks for all your hard work.
3. I often get asked what we do with folks who can't go right to foam rolling with the Foam Roller Plus (a more diesel version that is just foam on top of PVC).
In these folks, we usually start them with a foam-only roller - and ideally one that has been "broken in."
Another option that Cressey Performance has pioneered is suited up in catcher's gear before rolling. Safety first, folks.
4. Just wanted to give you a quick heads-up on an upcoming seminar (4/17-4/19) in Central Virginia with an outstanding line-up of speakers. I'm bummed that I can't make it, but you should definitely check this out if you're in the area:
Central Virginia Performance Seminar
They have limited the event to 75 attendees, so be sure to register sooner than later.
5. My girlfriend had the Oscars on last weekend, and I couldn't help but wonder who the heck this guy is and what he did to Ferris Bueller!