Article Reviewed: “Similarity in Adaptations to High-Resistance Circuit vs. Traditional Strength Training in Resistance-Trained Men.” Pedro E. Alcaraz, Jorge Perez-Gomez, Manuel Chavarrias, and Anthony J. Blazevich. Journal of Strength and Conditioning Research. 2011 Sep 25(9): 2519-2527.
This study investigated the effects of eight weeks of two types of heavy weight training workouts, one involving circuit training protocols and another using traditional strength training protocols.
How weight training exercises are arranged in a workout is referred to as exercise order. One common way to design a workout is to perform all the sets for one exercise before moving on to another, a method referred to as station training. The following is one simple example of how an upper body workout might be organized using station training, using two pressing exercises and two pulling exercises:
A. Pressing Exercise #1: Bench Press: 10 reps x 2 sets
B. Pulling Exercise #1: Seated Cable Row: 10 reps x 2 sets
C. Pressing Exercise #2: Triceps Pressdown: 10 reps x 2 sets
D. Pulling Exercise #2: Barbell Biceps Curl: 10 reps x 2 sets
The concept of circuit training was introduced to the sport science community in 1953 by physiologists at the University of Leeds in England. Its purpose was to integrate several components of fitness into a single training session. Rather than the usual practice of completing all the sets of an exercise before moving on to another exercise, circuit training involves performing exercises in sequence so that two or more sets of an exercise are not performed in a row. Using the exercises in the previous example, here is the same workout performed in a circuit fashion:
A. Bench Press: 10 reps x 1 set
B. Seated Cable Row: 10 reps x 1 set
C. Triceps Pressdown: 10 reps x 1 set
D. Barbell Biceps Curl: 10 reps x 1 set
E. Bench Press: 10 reps x 1 set
F. Seated Cable Row: 10 reps x 1 set
G. Triceps Pressdown: 10 reps x 1 set
H. Barbell Biceps Curl: 10 reps x 1 set
Two advantages of a circuit workout are that it can be completed faster and also can produce greater energy system benefits.
A variation of circuit training called supersets combines two different exercises, such as the following.
A1. Bench Press: 10 reps x 2 sets
A2. Seated Cable Row: 10 reps x 2 sets
B1. Triceps Pressdown: 10 reps x 2 sets
B2: Barbell Biceps Curls: 10 reps x 2 sets
The most common superset pairs agonist and antagonist muscles. The muscle that causes the primary movement is the agonist, or prime mover. When the agonist muscle contracts, the opposing muscle, which is the antagonist, is relaxed. Thus, when you perform a biceps curl, the biceps are the agonists and the triceps are the antagonists; but when you perform a triceps pressdown, the triceps are the agonists and the biceps are the antagonists.
Pairing agonist and antagonist muscle groups is the most common form of supersets, but you can also superset exercises for the same muscle group to upgrade the training stimulus. The two major types of these supersets use the principles of pre-exhaustion and post-exhaustion.
With pre-exhaustion supersets, a muscle is first fatigued by a single-joint exercise and then further exhausted by a multi-joint exercise involving the same muscle group and additional muscle groups. One example is performing a biceps curl followed by a chin-up. With a post-exhaustion superset, a compound exercise is followed by an isolation exercise that taps into the same motor pool of the muscle you want to focus on. An example would be a chin-up followed by a biceps curl.
Because of the technical nature of the exercises they perform in competition, weightlifters must focus on station training. Further, as these lifts are considered total body lifts, supersetting an exercise between the Olympic lifting exercises could affect performance in those lifts. For example, performing a bent-over row between sets of snatches could affect the athlete’s ability to maintain optimal alignment of the spine during the snatch.
The study in question involved 33 participants. They were all about 22 years of age, and all had been performing resistance training for at least 12 months before the experiment. The authors said the subjects “…could produce a force equal to twice their body mass during an isometric squat lift and had no recent injuries or medical conditions that would prevent maximal exertion.”
There were three groups: a circuit group, a traditional training group, and a control group that did not lift. Pre- and post-testing were performed on the following: body composition (using dual x-ray absorptiometry); maximum dynamic strength for one repetition on the bench press and half squat; peak power output on the bench press (using 30, 45, 60, 70 and 80 percent of the 1RM); maximum lactate and maximum power using a 30-second Wingate test; and a 20-meter shuttle-run test.
Both lifting groups performed the same exercises, which were leg curls, bench presses, standing calf raises, lat pulldowns, half squats and preacher curls. For both these groups there was a one-week introductory period, followed by eight weeks of training. At the start of the program both groups performed 3 sets of 3 reps per exercise, and an additional set was added every two weeks so that by the end of the experiment all the subjects were performing 6 sets of 6 reps.
The traditional training group performed three exercises, with three minutes between sets, followed by a five-minute rest, and then the group performed the remaining three exercises, with three minutes rest between sets. The circuit training group performed a combination of three exercises in a circuit, with 35 seconds of rest between sets, followed by a five-minute break, and then they performed the remaining three exercises. The authors referred to the combination of the three exercises as a short circuit; in bodybuilding, this is commonly referred to as a tri-set.
For the traditional training group, the exercises were arranged in the following order: leg curl, bench press, standing calf raise, lat pulldown, half squat and preacher curl. For the circuit training group, the first circuit consisted of the leg curl, bench press and standing calf raise; the second circuit consisted of the lat pulldown, half squat and preacher curl.
The authors noted that both training groups were just as effective in improving weightlifting 1RM and peak power, shuttle-run performance and lean mass. However, significant decreases in bodyfat occurred only in the circuit strength training group. Furthermore, the high-resistance circuit was more effective in improving peak cycling power.
This study was significant because it involved an independent evaluation of circuit training/supersets and station training. The key factor to look at in the program design is that the circuit training group completed their workouts faster. When performing three sets per exercise, the circuit training group only took 55 minutes to complete their workouts, versus 105 minutes for the traditional training group. When performing six sets, the circuit training group took just 78 minutes to complete their workouts compared to 125 minutes for the traditional training group. And because there were no significant differences in improvements in strength or muscle between the two groups, we can look at it this way: The circuit training method enabled the subjects to achieve nearly identical results in approximately half the training time.
Another important distinction is that only the circuit training group experienced a significant decrease in bodyfat – and note that no aerobic training was performed. This study supports the concept of the German Body Comp training protocols to lose weight, which suggests that the short rest intervals increase the production of growth hormone. Had the two groups worked out for the same amount of training time, it’s possible that even greater decreases in bodyfat could have been achieved. In fact, the results of this study support the way I have been designing workout programs for the past three decades, which is to focus on supersets in most workout programs.
The researchers did well in controlling the loading parameters of the workouts, but I thought the choice of exercises and the exercise order were a bit odd. One exercise used a relatively small muscle group, the calves; and although an isolation exercise for the biceps was performed, there was no exercise for its antagonist, the triceps. Also, because the squat is the most difficult exercise in the programs, it would have made more sense to make it the first exercise, rather than put it in the second half of these workouts.
For the highest levels of performance, weightlifters or those seeking to achieve maximal results in these lifts and their related exercises should concentrate on station training. That being said, for individuals interested in making maximal changes in body composition without losing strength, a circuit training approach is superior to traditional station training. Further, the use of supersets and circuit training significantly shortens workout time.