Monday, December 25, 2017


From the first time we grasp a barbell of a dumbbell, we are told to adhere to certain specific rules for proper exercise style. One such rule is to use strict exercise form, no cheating and full ROM (range of motion).

Cheating would be defined as using muscles other than prime movers of the specific muscles that you are targeting to lift the weight. An example of this is heaving the weight up when doing barbell curls. When you do this, much of the stress on the targeted muscle, namely the biceps, is shifted to other muscles, such as the lower back muscles and traps. Not only does this reduce stress on the biceps, but it can also result in a lower back injury. But as the cliché' says, not everything is written in stone, or in this case, iron. Doing a few cheat reps after a strict set of curls seem to place additional stress on the biceps that can foster muscle gains.

Another frequently mentioned must do dogma is to use a complete range of motion (ROM) when doing any and all exercises. The idea behind this is twofold: using a complete ROM involves more muscle fibers, and using a full ROM also produces greater degrees of muscle flexibility, indeed, the notion of being muscle bound is often thought to be related to having an abundance of muscle, as in a champion bodybuilder. In fact, while some states of being muscle bound may refer to shortened muscles that cannot reach their full ROM, most of it is sheer muscle size impacting the total flexion at the joint. Getting 'muscle-bound' is really a myth.

 In fact, many argue that pushing full ROM may not be kosher. Back in the early sixties, the famous York PA. Barbell Company began selling what they called an "Iso-metric power rack." This consisted of two upright columns with holes punched throughout. The idea behind the power rack was to set a barbell on the rack at the precise point of an exercise sticking point. For example, for most people, the sticking point, or the point where the weight is hardest to lift, occurs at exactly mid range or more towards the 'lockout' point in the exercise. So to overcome this sticking point, the bar is placed on the rack at those positions. You then do partial ROM sets on the power rack. But the trick is that by using a partial ROM style, you can load the weight far heavier than you would do it you were doing a complete ROM. This 'overload' at the sticking point may build more strength at that angle, and if it all works out right, you get stronger at your sticking point.

Valdimir M. Zatsiorsky was one of the architects of the Soviet bloc training system that produced a myriad of world and Olympic champions. He was a strong believer in the use of a partial ROM, which he called "Accentuation training." Zatsiorsky felt that it made sense to use partial range of exercise motion exercises to build maximum power in areas of the muscle involved in particular athletic activities. Other scientists felt that using a partial ROM maximized force production since the heavier weights used in such movements decreased neural inhibition of muscular contraction, one of the primary breaks on strength in the human body.

 More recently, a partial ROM has been advocated by John Little and Peter Sisco in their 1997 book, Power Factor Training. Little and Sisco believe that partial ROM training, or what they call "power factor training" is far superior to doing full ROM for a number of reasons.

For one, using a partial ROM allows the use of much heavier weights, which would place more stress on the type 2B muscle fibers that are most amenable to gaining strength and size. These particular fibers are only activated by using heavier weights, so in that sense, Little and Sisco's idea is true. They also note that this style of training is more efficient, since it  places immediate stress on the type of muscle fibers that grow without having to do a lot of exercise to reach the same goal. As a result, workouts are intense, but also short and infrequent to allow time for the trained muscle to recover and compensate for imposed muscle damage.

Others use a full range of motion and a partial range of motion. A good example of this was how Larry Scott trained. Scott liked to do preacher curls to train this biceps. He would do six reps with a heavy weight, and then do a few short half reps that he called "burns" to work the muscle past the point of fatigue. Scott felt that this method promoted increased muscle growth, and viewing the stupendous biceps development that earned him two successive Mr. Olympia titles (1965, 1966), it's hard to argue with his logic.

As for the scientific point of view, the studies that have examined or compared full range of exercise motion to partial reps have been thus far equivocal, with some studies showing superiority of one form over another. One study, for example, found that doing partial ROM when doing barbell curls produced a significantly higher heart rate, blood pH level, and lactate level compared to using a full range of exercise motion. This is significant because increased lactate is thought to act as a signal for the release of intramuscular anabolic hormones, such as IGF-1.

Another study compared partial ROM and full ROM in the bench press exercise. Subjects in the study were tested for maximum bench press lifts using both one and five reps. The study found strength improvements when doing partial ROM, but non when doing full ROM. The authors of the study suggested that training using only full ROM fails to optimally train the areas of the muscle where full force production occurs. They felt that using a partial ROM allows optimal force production because it eliminates the usual sticking points of an exercise that occurs with a full ROM. Indeed, muscle rehabilitation exercise often involve using partial ROM to strengthen injured muscles that otherwise are incapable of completing a full ROM. This method not only prevents muscle atrophy and promotes healing, but also minimizes the production of scar tissue within muscle structures.

One possible problem with using only partial ROM training is comparable to what happens when isometric exercise is done. Isometric exercise is known to boost muscle strength-but only at then angle where the muscle is trained. Isometrics involve forcibly contracting a muscle at a specific angle, with no actual movement. It's not hard to understand that using a partial ROM likewise will only strengthen a muscle at the particular angle that it's trained. The rest of the muscle would remain unaffected, which means probable less muscle mass and strength development in the long run. To work around this problem, other styles of partial ROM exercise, such as Steve Holman's "Position of Flexion" system feature using a variety of partial ROM movements to work larger portions of the muscle.

A study of inexperienced women trainees had the women doing partial ROM bench presses, along with full range bench presses and a a combination of both. The women showed a 34.8% gain in strength when doing full ROM: 22.5% when doing partial ROM: and 23.1% gain with mixed training. In the most recent study that compared partial ROM with a full ROM, the exercise used was preacher curls, and the subjects were 40 young untrained men, average age, 21. Unlike previous studies, this study also measured muscle thickness improvements in the subjects. The results showed that those using the full ROM gained slightly more strength compared to the partial ROM group, despite the fact that the partial ROM group used 36% heavier resistance. But gains in muscle thickness for the biceps didn't differ significantly between the two groups, with the full range exercise group gaining slightly more mass than the partial ROM group.

The authors also suggest that full range of motion exercise is safer than partial ROM. But there is a place for partial ROM for advanced trainees and athletes. Using this training technique can help you blast past sticking points on exercises, as well as produce more power at certain angles of movement that would be useful in various sports competition.

REFERENCES: Ronei, P, et al. Effect of range of motion on muscle strength and thickness. J Str Cond Res 2011: in press

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