To most bodybuilders and fitness enthusiasts, "circuit training" is thought of as a method of integrating resistance and aerobic exercise by performing several (9-12) exercises in "vertical" progression (meaning that one performs one set of each exercise until all have been completed, as opposed to finishing all sets of the first exercise before progressing to the second) with little or no rest between exercises. The supposed (and unproven) benefit of this type of high density (work to rest ratio) exercise is that the exerciser will improve aerobic and anaerobic functioning at the same time.
Unfortunately, this narrow definition has done a disservice to circuit training, and to those who have dismissed this method as an ineffective fringe variant used only by the profoundly unfit as a way of regaining some semblance of fitness. In truth, circuit training has much to offer, even for the advanced, if you'll allow for a slightly broader definition of the term, and a bit of creative application.
Exercise Order
Whenever you plan a day's workout, you have two possibilities when it comes to planning the order of exercises: You can use a "station training" or "horizontal" approach, which means that you finish all sets for the first exercise before proceeding to the next, and so on, until all exercises have been completed; or you can take a "vertical" approach which means that you perform one set of each exercise until all have been completed.
In other words, you have performed a "circuit," regardless of how long the rest intervals were, what exercises were performed, and the number of exercises you did. Of all the parameters associated with traditional circuit training, only the vertical orientation of exercise order is truly unique to circuit training. With this in mind, it's clear that circuits can be performed with long rest intervals, a small number of exercises, and in fact, as we'll discuss shortly, circuits can be composed of very "non-traditional" exercises.
Why Train "Vertically"?
Acclaimed Soviet sports scientist and author of the excellent text Science and Practice of Strength Training, Dr. Vladimir Zatsiorsky points out that when designing short term programs, the key factor is your ability to manage fatigue. Zatsiorsky points out that the effects of fatigue are relatively specific. In other words, the fatigue which accumulates from a set of a given exercise will adversely affect another set of that same exercise more than it would affect a set of a different exercise.
This fact, coupled with the fact that circuit training allows for more rest between sets of the same exercise (without extending the length of the workout), allows for a higher level of intensity.
Choice Of Exercises
Although traditionally, circuit training is performed on machines (probably due to the fact that circuit training has been marketed to the novice crowd, and also because machines are faster to "set up" which facilitates short rest intervals), you need not worship tradition. Not only can circuits be performed with free weight exercises, they can also involve exercises performed with medicine balls, bodyweight (calisthenics), or exercises designed to promote power (sprints, jumps, etc) flexibility, or aerobic endurance.
When choosing exercises for your circuit, keep in mind:
- Don't limit yourself to machines (or even weights, for that matter). Circuits may include "hard core" exercises like squats, power cleans, and bench presses, as well as movements done on exercise balls, or with medicine balls, aquatic equipment, elastic tubing, you name it. You might even decide to include sprints and plyometric drills.
- Variation is a key factor in intelligent programming. If you plan for 3 circuits per week, consider creating a different circuit for each day. After a few weeks, create 3 totally new circuits, and start again. You may even wish to assign different repetition schemes for each day (example: Monday and Friday, perform 12 reps per set, and on Wednesday use 8 reps per set).
- Stay flexible! A common problem when performing circuits at a commercial facility is to find that someone else is at the station you want at exactly the wrong time. When this happens, select a substitution exercise for that particular circuit.
Remember: Training plans usually have to be modified from time to time due to unforeseen circumstances!
Number Of Exercises and Circuits
International strength coach Charles Poliquin suggests that no more than 25 total sets be performed in a single session. Why only 25 sets? First, circulating androgens appear to remain in the bloodstream for about 45-55 minutes after the workout begins. Exceeding 25 sets is likely to extend the workout beyond this period of time, which means you won't be training in the most ideal hormonal environment for positive adaptations.
The second reason to limit your workouts to no more than 25 sets is that there is an inverse relationship between volume (or the amount of work) and intensity (difficulty).
In order to maintain sufficient intensity for muscular adaptations, the volume must be limited. With the above recommendations in mind, we can quickly calculate that for a circuit composed of 8 exercises, no more than 3 circuits should be performed. If your circuit consists of 12 exercises, no more than 2 circuits should be performed.
Number Of Repetitions
Circuit training is NOT synonymous with high repetitions! Regardless of how you structure your workouts, the ideal number of repetitions per set is a function of the type of adaptation you wish to achieve. There are two broad categories of adaptation which can be achieved through resistance training—increased muscular cross-section (hypertrophy) and an improvement in ability to recruit a high percentage of existing muscle fibers (intramuscular coordination).
Two General Categories Of Strength Training Methods
Bodybuilding Method: Also called the hypertrophy method or the repeated effort method.
- Load: 70 to 85% 1RM
- Repetitions: 5 to 12
- Effect: Hypertrophy of muscle fibers.
Note: Bodyweight increases, absolute strength improves, relative strength decreases.
Neurological Method: Also called maximal weights method.
- Load: 85 to 100% 1RM
- Repetitions: 1 to 4
- Effect: Improved recruitment of existing muscle fibers
Note: Bodyweight remains constant, absolute strength increases, relative strength increases.
Bodybuilders and fitness enthusiasts should not ignore the neurological method, since improved maximal strength will lead to the ability to lift greater loads for whatever set/rep scheme you're using. This in turn leads to greater muscle mass.
Where To Start?
The easiest way to immediately take advantage of circuit training is to simply perform your usual workout, but "vertically" instead of "horizontally." This simple adjustment is in many cases the trigger for renewed growth, especially for those (and there are many!) who train too monotonously.
Circuits can be integrated with other commonly used intensity building techniques, such as partial repetitions, strip sets, isometrics, and eccentrics. If you keep a training log, a great way to develop ideas is to look back at some previous workout sessions, and re-configure them into circuits. You'll end up with endless of combinations that will keep your training interesting and result producing for months to come. In fact, I find that most people rarely go back to conventional station training after giving circuits a serious run for the money.
Comparing Horizontal Versus Vertical Orientation For Managing Fatigue
Horizontal Orientation
- Set 1: Squat 225x10
- Set 2: Squat 225x10
- Set 3: Squat 225x10
- Set 4: Squat 225x10
- Set 5: Squat 225x10
- Set 6: Incline Bench Press 185x10
- Set 7: Incline Bench Press 185x10
- Set 8: Incline Bench Press 185x10
- Set 9: Incline Bench Press 185x10
- Set 10: Incline Bench Press 185x10
Note: Tempo = 3 seconds per repetition, or 30 seconds for each set. Rest interval is 2 minutes between sets. The downside of this style of training is that 1) you only have two minutes rest between sets, which causes fatigue to accumulate, and 2) the second exercise suffers due to this accumulating fatigue.
Vertical Orientation
- Set 1: Squat 225x10
- Set 2: Incline Bench Press 185x10
- Set 3: Squat 225x10
- Set 4: Incline Bench Press 185x10
- Set 5: Squat 225x10
- Set 6: Incline Bench Press 185x10
- Set 7: Squat 225x10
- Set 8: Incline Bench Press 185x10
- Set 9: Squat 225x10
- Set 10: Incline Bench Press 185x10
Note: Tempo = 3 seconds per repetition, or 30 seconds for each set. Rest interval is 2 minutes between sets. With this approach, each exercise is affected equally by accumulating fatigue. Also, and perhaps more significantly, you are able to rest 4.5 minutes between each set of the same exercise. This allows for greater intensity (and therefore, results). For purposes of simplicity, this table only shows two exercises. The more exercises in the circuit, the longer the rest interval between sets of the same exercise.