The word “intensity” has been given many meanings in the context of weight training and bodybuilding. For example, some strength coaches say the true definition of intensity is the total amount of weight you lift or the amount of weight you can lift relative to your one repetition maximum (“load” intensity).

Other bodybuilding experts claim that optimum measure of intensity is the amount of perceived momentary muscular effort you can exert during a set (“effort” intensity).

I have also seen intensity defined as the amount of muscle building hormones released as a result of a workout (“anabolic” intensity), and the amount of physical stress imposed on the body (“relative” intensity).

Density: The Forgotten Intensity Secret!

There is yet another definition of intensity which few people ever consider yet it is equally, if not more important, than any other form of intensity—including load intensity! If you performed four sets of squats with 185 pounds in a span of eight minutes during workout #1 and then you decrease your rest intervals so that you perform the same four sets at the same rep tempo with the same 185 pounds in six minutes during workout #2, then you have successfully overloaded your muscles and increased the intensity of your workout. This will give you the result you want: More muscle!

This type of intensity is so important that it has been given its own name: “DENSITY.” Density is the amount of muscular work you can perform in a specified period of time.

I’m not sure who originally coined the term “density” as it relates to strength training, but certainly strength coach Charles Staley deserves a lot of credit for popularizing use of the term in recent years with the 2002 release of his book Escalating Density Training also known as EDT (visit Charles at www.integratedsportssolutions.com for more information).

Although mainstream use of the term “density” may be new, the principle behind the name is not. The first time I heard of high density training was in 1983 when first I picked up a Joe Weider Muscle and Fitness magazine as a young teenager interested in learning about bodybuilding. Joe Weider, who was known for compiling bodybuilding training principles (and adding his name to them as part of the “Weider System”) was a proponent of the density principle for pre-competition training, although he called it the “Weider Quality Training principle.”

I never thought “quality training” was a good name for the technique because it was not accurately descriptive. If you look up density in Webster’s dictionary, it will give the definition as, “The quantity per unit area, unit volume or unit length.” If you add the unit of time, then “density” is truly the most accurate and descriptive way to name the technique.

In Weider’s 1983 book, “The Weider System of Bodybuilding,” Joe wrote,

“The Weider quality training principle is a vital tool in the arsenal of any serious bodybuilder during a precontest training cycle. Quality training consists of progressively reducing the average rest interval between sets from approximately 60-90 seconds during the off season, down to as little as 15-20 seconds at the end of the precontest cycle. This words hand in glove with a tight precontest diet to bring out the maximum degree of muscularity and muscle density in a bodybuilder’s physique.”

The benefits of the density technique go far beyond bodybuilding. In fact, for busy executives, (which is about as far from competitive bodybuilding as you can get), various forms of density training may be the perfect solution staying fit on a tight schedule.

My next exposure to the subject of high density training came from legendary bodybuilding trainer Vince Gironda. Just one year after being introduced to bodybuilding magazines by Joe Weider, I then stumbled onto Vince Gironda’s training courses and his 1984 book, “Unleashing the Wild Physique” via Robert Kennedy and Muscle Mag International. Gironda was a strong advocate of high density training in general, but specifically, by using a system he pioneered called 8 sets of 8 which involved minimum rest between sets, ultimately with as little as 10-15 second rest intervals.

Years later, the subject of high density training emerged again when Charles Staley released his EDT book, which is a completely new, unique and highly effective way to apply the density training principle. In the book, Charles gave an excellent summary of the density principle. He writes,

“Other programs focus mainly on manipulating volume (usually by increasing it). EDT acknowledges the importance of both volume and intensity, but focuses primarily on a little appreciated, yet critically important facet of the training load called ‘density.’ Essentially, density is the work/rest ratio of your training. Your (muscles) will get bigger when you force them to do gradually more and more work in the same period of time.”

Okay, enough history and background. By now you’re probably drooling at the prospect of finally discovering a legitimate method of gaining more muscle in less time and you want all the gory details! Patience, we’ll get to that in just a moment. Frst, let me explain exactly how high density training works, how it will benefit you and when it’s best to use. Then I’ll give you the goods and show you six different ways you can use the technique yourself.

High density training is simply when you condense more muscular work into less time, thereby achieving increased intensity and progressive overload with or without increasing the weight.

Many things are debatable when it comes to strength training. In fact, I’ve never met any two trainers who agreed 100% on everything. However, one thing that is accepted universally by ALL trainers is that progressive overload is an absolute requirement in order to increase muscle growth—it’s the foundational principle of all effective strength training programs.

Many people believe that the only way to apply progressive overload is to increase the amount of weight you use with each successive workout. That’s known as progressive resistance, but progressive resistance is only one of many possible ways to achieve progressive overload. Increasing density is a method of progressive overload, which, while not capable of replacing progressive resistance completely, has many unique benefits that cannot be duplicated with any other form of training.

The Many Benefits of Density Training

One great benefit of high density strength training is time efficiency: It allows you to complete a highly effective and result producing workout in as little as 30-45 minutes. In fact, with split routines, you can zip through a couple of body parts in as little as 20 minutes leaving time for cardio (if necessary) and still getting done with the entire workout in under 45 minutes. In this day and age, a legitimate method to get an effective workout in less time is a godsend. Trainers who specialize in workout efficiency and or workouts for executives and other busy people usually use the density principle heavily in a variety of ways.

Another advantage of high density strength training is that it can allow you to work around sore joints and injuries. If you’re suffering from an acute injury, or any serious injury, naturally you should follow the advice of your physician and avoid stressing the injured area at all. However, if you’ve been training for a long time, you are no doubt familiar with those achy, painful joints and muscles that are not “major injuries”, but are more like “annoyances” that often prevent you from training as heavily as you’d like. If, despite feeling the aches and minor pains, you get a little bold and you slap on more weight than you should, that annoying “irritated” area often turns into a full blown injury that sets you back days or even weeks before you can train it at all. This is a frustrating and probably all too familiar scenario for an awful lot of people.

The ultimate solution is of course, to seek a health and fitness professional to help you find the cause of your pain and fix the problem from its source, but if minor joint or muscle pain is preventing you from training heavy, then don’t train heavy! Many people get themselves in great trouble because they labor under the belief that they “must” use weights as heavy as possible or their training is in vain. Many training systems (which shall remain nameless) that call for heavy loads all or most of the time are partly to blame. The alternative is to train with lighter (moderate) weights with briefer rest intervals…. Aka “density” training!

Overload and intensity are necessary to achieve muscular growth, but that overload/intensity does not have to come in the form of extremely heavy weights. For example, if you are a 300 pound squatter, you probably believe that you must use 85% (255 lbs) or more for maximal strength gains, and 70% or more for maximal hypertrophy. Not true. Take 150—185 pounds and squat it for 8 sets of 8 reps with 30 seconds rest between each set and see how “heavy” that weight feels to you by the last few sets. More importantly, continue with that protocol for 6-8 weeks, adding weight with every workout while maintaining or even reducing your rest intervals further to 15-20 seconds and see what type of muscle growth and fat loss you experience. I assure you…. You will be amazed (if you can get through it! This is not an easy workout and its not for beginners).

Density Training for Fat Loss

A third reason to use high density training is to increase the effects of a fat loss program by burning more calories in a given time period and by maximizing the hormonal response to training. This is particularly effective when you train the large muscle groups and compound movements. When you shorten your rest intervals to 30 seconds or less on exercises such as barbell squats, you may be stunned to find out how cardiovascular the workout becomes. In fact, cardiovascular fatigue can often be the limiting factor in high density workouts while training legs, at least during the initial phases until your conditioning improves.

Your heart rate spikes after the set, and recovers partially during the brief rest interval, but not fully, so your heart rate stays up the entire duration of the workout. You burn more calories in less time, your metabolism is stimulated more, and you unleash a flood of fat burning and muscle building hormones.

If this sounds good so far, then hold on to your hats, because it gets even better! The high density method can be literally doubled in effectiveness by going beyond a simple reduction in rest intervals between sets and adding progressive resistance into the equation. As you adapt to each reduction in rest intervals, you simultaneously increase the amount of weight you use, effectively achieving a “double overload factor.” By increasing density and resistance in the same training cycle, this “double overload” can produce results beyond your wildest imagination.

With all these benefits, density may sound like the “ultimate” training method… the end all be all… the mother of all workouts! Well, not exactly. First, there is no single best training method. Second, every technique carries it’s own unique set of risks and benefits and there are trade-offs involved. In the case of high density training, the trade off is strength. When you reduce your rest intervals progressively, invariably the amount of weight you can handle is reduced. This means that density training is not the ideal method if one of your primary objectives is strength. To develop maximal strength, longer rest intervals are a necessity—sometimes as long as 2—5 minutes between sets. If your goals include health, fitness, bodybuilding, or fat loss, and if you want to get the best results in the shortest time possible, then high density training may very well be the “ultimate” method for you under those circumstances.

For the purpose of out discussion, the general definition of high density training is any resistance training with rest intervals between straight sets on the same exercise of 30-40 seconds or less.” High density training also includes any resistance training where two or more different exercises are performed in a row with no rest between exercises (or only the amount of time it takes to move from one exercise to the next).

Lets now take a look at some of the various ways you can use high density training.

Basic HDT

The most basic way to use high density training is to take the workouts you’re already doing within 60-90 second + rest intervals and simply begin to decrease the rest periods in a gradual fashion every workout until you’re down to 20-30 seconds between sets. In some cases the rest intervals may go as low as 10-15 seconds between straight sets. In the case of supersets, trisets, giant sets and circuit training, the rest intervals between exercises are eliminated completely.

Supersets, Giant Sets and TriSets

Conventional weight training is done using “straight sets.” A straight set consists of a series of nonstop repetitions, usually somewhere between 6 and 12, followed by a brief rest interval of about a minute. A superset is an advanced training technique where you perform two exercises in a row with virtually no rest in between exercises. Supersets are an excellent technique for muscular development, especially if you are short on time. Supersets are not, however, the most effective technique for building strength. Let me explain why…

When you perform two exercises in a row with no rest in between, this will reduce the amount of weight you can handle, particularly on the second movement. Your strength will also decrease from fatigue and lactic acid buildup with each subsequent superset. Because supersets don’t allow you to use maximal weights, they are definitely best for body building and body-shaping, not power or strength training.

Staggered Sets

A staggered set is a type of superset where you combine a major muscle with a minor and completed unrelated muscle (not same muscle group or even the antagonistic muscle group). This technique is most commonly used for abs and calves. The way you utilize this principle is to “squeeze in” a set of abs or calves in between sets for any major muscle group. For example, you could throw in a set of abs in between every set of chest you do. Instead of resting and doing nothing in between sets of chest, you are doing something productive—working your abs—and keeping your heart rate up. This also gets your workout finished much more quickly and spares you the monotony that many people feel from doing these small body parts by themselves.

Recently natural bodybuilding champion Ken Babich of www.quadfather.com told me that the “old timers” had a name for this: “In flux training.”. Ken said,

“I never sit down during my workout and I keep some muscle working the whole time. For example, I will do one set on an exercise for a major muscle group, making it a point to stay in my set for 30 seconds to get the most out of it. Then, instead of resting, I immediately do an abdominal exercise. The “old timers called this “in-flux training,” meaning that some muscle is being worked during the entire workout. This fires your metabolic rate through the roof; hence you can eat well but stay lean.”

Circuit Training

Circuit training is a very broad term that has been used to describe a variety of different training methods—all with one commonality: Rather than doing successive sets on one exercise before moving to the next exercise, a circuit consists of a sequence of different exercises performed for one set each in a continuous fashion with little or no rest in between exercises.

For the purposes of our discussion, we will refer to circuit training as any sequence of five or more exercises in a row with little or no rest in between each exercise. I say five or more because two, three and four exercises in a row have their own names; supersets, trisets and giant sets (or “quad sets”) respectively.

The conventional “circuit training” method usually involves working your way through one set each of 8-12 exercises (usually 8-12 reps each, but reps may vary). Every muscle is trained in the circuit and you move from one machine or station to the next without resting between exercises except for the time it takes to move from station to station. Once you reach the end of the entire 8-12 exercise circuit, then you take a rest period of 60-120 seconds and then repeat the entire circuit 1-2 more times.

This traditional method of circuit training which includes such programs as Curves for Women, is generally considered a beginners technique for health, fitness and weight loss. Circuit training not an effective bodybuilding technique. Bodybuilders and those seeking muscle growth are generally better off using multiple consecutive sets or supersets, trisets and giant sets on the same muscle group. However, there are some trainers who have become quite ingenious at devising unique ways to use circuits or mini circuits that can provide a nice balance between muscle development, fat loss and conditioning. For example two four or five exercise mini circuits for a specific muscle group can give a nice compromise between conventional training and circuit training.

8 Sets of 8

8 sets of 8 was the favorite training program of Vince Gironda, legendary trainer to movie stars and champion bodybuilders. Vince wrote, “I come back to this high intensity ‘honest workout’ more often than any other for maximizing muscle fiber growth in the quickest time possible for the advanced bodybuilder.”

The most common method to use the 8 sets of 8 routine is with a two day split, working half your body on day one, and the other half of your body on day two. Three to four workouts are performed per week.

One exercise is selected for each body part, usually 5-6 exercises per workout. Each exercise is performed in regular straight sets with very brief rest intervals, starting with 30-40 seconds.

Day 1:
Quadriceps, Hamstrings, Back, Biceps, forearms

1. Squats 8 X 8
2. Lying leg curl 8 X 8
3. Standing calf raise 8 X 15-20
4. Seated low cable row 8 X 8
5. Barbell curls 8 X 8
6. Wrist curls 8 X 8 (optional)

Day 2:
Chest, Shoulders, Triceps, Abs

1. Incline Dumbbell press 8 X 8
2. Seated Dumbbell press 8 X 8
3. Bent over dumbbell laterals 8 X 8
4. 2 dumbbell lying tricep extension 8 X 8
5. Weighted crunches 8 X 8

As you can see, this is a high volume workout with 40-48 sets per workout. Most experts would consider this type of volume to be overtraining, but with the shortened rest intervals, the workouts can be completed in as little as 30-40 minutes.

A more advanced version of the 8 X 8 routine using a three day split (or even a four day) split was described in Vince’s book, “Unleashing the Wild Physique” and I wrote an article for IRONMAN magazine about this a few years back. Vince reserved this method for professional bodybuilders such as Mohammed Makkawy and commented that most people with average genetics would overtain by using multiple exercises on the same body part. Unless you are an advanced bodybuilder with excellent genetics and recovery ability, the best way to introduce yourself to the 8 X 8 concept is with one exercise per body part is illustrated in the sample routines above.

Jon Benson’s 7 Minute Muscle

Jon has an exciting new take on HDT. Check out his e-book on the subject at www.7MinuteMuscle.com.

For more information on EDT training, visit www.EDTsecrets.com or www.integratedsportssolutions.com. Charles has published a book on EDT training for arms called, “The ultimate guide to massive arms EDT Training.” Charles also has plans for a complete full-length book on total body EDT training scheduled for release in 2005.

—Tom Venuto, CSCS