Authors: Orrin Whaley, Abigail Larson, Mark DeBeliso
Orrin Whaley, BS
Provo UT, 84601
Orrin Whaley is a student at Southern Utah University. Upon the completion of this research project he will earn a MS in Sports Conditioning and Performance.
Progressive Movement Training: An Analysis of its Effects on Muscular Strength and Power Development
Purpose: Muscular strength and power are important attributes in many sports, so research on training methods that may improve these attributes is of high interest. One such training method is PMT, which incorporates a partial ROM movement with a supramaximal load. This study attempted to compare PMT to traditional full ROM training by comparing 1 RM back squat, vertical jump height, and power output scores from the two groups. Methods: Thirty-six high school male subjects were randomized to participate in a 7-week squat program in either the PMT group (n=21) or the full ROM group (n=15). The subject’s weight, 1 RM back squat, and vertical jump were measured prior to and upon completion of the training program. Power output was calculated using the subject’s weight and vertical jump height (8). Results: The study included 36 male high school students who were enrolled in a weight training class (n=15 in the full ROM group and n=21 in the PMT group). The PMT group saw significant (p<.001) increases in vertical jump performance (cm) and power output (watts) from pretest to posttest, but the full ROM did not. Significant increases (p<.001) in back squat strength were observed in both groups from the pretest to the post-test. The percent improvement from pretest to posttest was compared between groups on all three performance measures, with no significant differences found (p>.05), indicating that both forms of resistance training provide comparable benefits for increasing lower body strength and power. Conclusion: PMT is as effective and may be more effective than full ROM training for increasing lower body strength and power.
Key words: squat, vertical jump, power output, range of motion
Progressive overload is a foundational principle of strength training and is generally accomplished by manipulating such variables as intensity, volume, rest times, and frequency (7). Increasing one’s range of motion during an exercise may also be considered a form of progressive overload. This resistance training (RT) style was originally called “progressive movement training” (PMT) (2); therefore, this term will be used in the present study. Progressive movement training employs the concept that rather than increasing resistance or volume solely as a means of progressive overload, an exercise’s range of motion is increased to make the exercise harder while using a consistent supramaximal load for the entire training cycle. In effect, PMT incorporates progressive overload by manipulating the variable of intensity in a manner varying from those discussed by Kraemer and Fleck (7).
Two famed strongmen from the 40’s and 50’s era, Bob Peoples and Paul Anderson, were prominent pioneers of PMT (19). Peoples, a man who deadlifted 330kgs in 1949 while weighing 82.3kgs (5), purportedly used to incorporate PMT into his deadlift workouts (21). He would dig a hole large enough for him to fit his feet and lower legs into while the weights on the ends of the barbell still rested on level ground (21). From this set-up, Peoples would perform partial deadlifts with a supramaximal load from a few inches below lockout. Gradually, he would fill the hole with dirt until he was performing a full range of motion lift with the once supramaximal load. Paul Anderson, a student of Peoples’ training style, also employed PMT with the back squat (19). Often squatting with large metal wheels or heavy metal drums on the ends of the barbell (acting as built-in safety mechanisms), Anderson would also dig holes in the ground and gradually fill the holes with dirt (19). It was largely publicized that Anderson reached a 545.5kg squat without the use of any supportive powerlifting equipment (17, 19).
When one compares the purported lifts of men like Peoples and Anderson to current powerlifting records, their strength feats are still impressive by today’s standards. Under similar conditions (raw drug-tested powerlifting), the modern-day record in the deadlift for the 83kg weight class is 330.5kgs (10). It is interesting to note that this record was set using a sumo-style deadlift in contrast to Peoples who performed his 330kgs lift using a conventional style. Even more astonishing, Peoples was over 40 years old at the time he completed his best lifts. The super-heavy weight world record in the squat is currently set at 477.5kgs (10), a mark that Anderson may have superseded back in the 1950’s. Peoples and Anderson had strength that was comparable to the best strength athletes today, despite the fact that they worked laborious jobs (in the case of Peoples), and had limited knowledge about nutrition and strength training by today’s standards. However, these men were researchers in their own right. They experimented constantly with various innovative training styles including PMT.
In recent times, it is undoubtable that some still employ the training methods used by Peoples and Anderson, however, in some ways these old-fashioned training methods seem to be largely forgotten. Most modern strength and conditioning texts fail to mention PMT and research literature is scarce if not non-existent. Consequently, in order to substantiate or refute one of the “myths” of yesteryear it is important to perform empirical research that aims to quantify benefits associated with this form of training.
Limited scholarly work has been performed on PMT, so by necessity many of the resources used to develop this study have come from non-scholarly sources including a document that was written by one of the original pioneers of this training style, Paul Anderson (2). Due to the lack of peer-reviewed research regarding the use of PMT as a means to improve maximal muscular strength and power, it is important that foundational research be conducted. Ideally, research findings will help us to identify the efficacy of PMT and the most effective way to program and implement this exercise modality into existing resistance training regimes. Presently, there is limited information on how the originators of this style of training successfully implemented it. Although ambiguous protocols for implementing PMT are available in various non-scholarly forms, the recommendations and practices are often conflicting, generally scarce, and unsubstantiated.
The purpose of this investigation is to determine the effect of utilizing a PMT program compared to traditional full range of motion resistance training (FROMRT) on measures of muscular strength and power. Specifically, will a 7-week PMT program improve lower-body muscular strength and power, as measured by the 1 repetition maximum (1-RM) back squat (BSQ), maximum height vertical jump (VJ), and VJ power output (PO) to a greater degree than a FROMRT program?
Male students from Monument Valley High School were recruited from multiple weight training class periods for participation in the study. IRB approval and parental and participant written consent were obtained from each participant prior to the study. All participants were free of injury and were able to perform a full range of motion (FROM) BSQ with safe technique prior to being admitted into the study. Individuals with injuries that may have affected squat performance as well as students who could not execute a safe FROM BSQ to an appropriate depth were excluded from the study. Participants were asked not to make any significant dietary changes (to not purposely increase or decrease their caloric intake or take new supplements) or to undertake any new exercise habits or activities that could otherwise affect muscular strength or power.
This study was performed at Monument Valley High School (Kayenta, Arizona, US) in weight training classes during the second (winter) semester. Prior to the initiation of the study, all individuals were asked to perform an unloaded Olympic bar FROM BSQ. This process was carried out in order to determine the participant’s ability to perform the movement safely and to a proper depth, (i.e. hip crease is the same height as the top of thigh or below it). Failure to meet this expectation disqualified the individual from participating in the study. Additionally, participants with pre-existing injuries that may have prevented them from being able to participate safely in this study were excluded accordingly. All qualified subjects from the participating class periods were randomly assigned by class period to practice either PMT or FROMRT for the entirety of the study.
Prior to and following the 7-week RT study intervention, a trained research assistant measured and recorded the weight of each participant on a Tanita digital scale (model TBF-300WA). The participant’s age, height, maximal VJ height, and 1-RM FROM BSQ were measured and recorded at this time as well. The testing consisted of a general standardized warm-up consisting of 4 sets of 30-second jump rope and one round of the dot drill (a 35-80 second foot agility drill that incorporates rapid ballistic movements) followed by a movement-specific warm-up. For the VJ test, the movement-specific warm-up consisted of a few minutes of practice jumps. The BSQ movement specific warm-up consisted of three to five progressively heavier sets of FROM BSQ and repetitions of 10, 6, 2, and then singles for the remainder of the warm-ups if needed.
Vertical Jump Test and Lewis Power Output
The VJ test was based on the protocol described by Miller (16). Each participant raised both hands high above their head with feet flat on the floor and reached to touch the highest Vertec marker they could in this position. This measured height was then subtracted from the subsequent VJ heights, so a VJ score could be recorded. The participants were then given a few minutes to perform warm-up jumps before beginning the test. When the participants where sufficiently warmed up, VJ was measured. Participants were allowed repeat jumps as long as they improved upon their previous score. When they failed to best a previous score, the participant’s maximum VJ score was recorded. The Lewis Formula (average power (watts) =√4.9 x mass (kg) x√VJ (m) x 9.81) (8) was used to combine the participant’s best VJ score and body mass to equate a PO value (in Watts). Following their last VJ attempt, participants prepared for the FROM BSQ test.
One Repetition Maximum Back Squat Test
The 1-RM FROM BSQ test was based on the protocol described by Miller (16). Individuals performed between 3 and 5 warm-up sets (depending on strength level) with progressively heavier loads. The participants then rested a minimum of 3 minutes before taking their first 1-RM FROM BSQ attempt. Three FROM BSQ attempts were allowed to establish a 1-RM. A minimum of 3 minutes rest was allowed between each attempt. For an attempt to be considered successful, participants had to squat to a depth where their hip crease was level with or below the top of their thigh then return to the starting position without any external aid. Participants in this study wore no supportive equipment (i.e. knee wraps, squat suits, etc.) during any of the testing or RT sessions.
7-week Training Intervention Protocols
The 7-week RT period started at the beginning of the week following the testing day and is outlined in Figure 1 and 2. Figure 1 depicts set and repetition information as well as duration and intensity for the participants in the FROMRT group and Figure 2 depicts the range and repetition protocol for the PMT group. The squat days 1, 2, and 3 were performed anytime during the week (even in succession), however, a Monday, Wednesday, Friday schedule was recommended. Since it was somewhat uncertain how the participants would respond to the PMT protocol as prescribed, due to potential variability caused by varying heights of the subjects and the general lack of literature and research on the subject, participants were instructed to decrease the load lifted in 5% increments if they were unable to perform at least two repetitions per set at a given range. Likewise, if the participants were unable to complete the sets and repetitions with the loads prescribed in the FROMRT program, they were told to reduce all subsequent loads by 5% increments until the loading protocol was appropriate. All load adjustments were rounded to the nearest 5 lb. (2.3kg) increment.
The FROM front squats (FSQs) and FROM BSQs were performed to the same depth and standard as the 1-RM test procedures. The PMT BSQ training was performed in a power rack using 4.45 cm increments. The power rack safety arms were spaced 8.89 cm apart, so a 2.54 cm and a 1.91 cm plywood board were placed under the subject’s feet to mark the appropriate range of motion for every other range height (see Figure 3). The 1st position (Range 1) was the pin that was closest to the subject’s lock-out (the position of full extension about the hip and knee joints) and was placed in the position just below the J-hooks that were set-up appropriately for the subject (the J-hooks were placed in the highest position that allowed the athlete to un-rack the barbell and walk backwards without catching the barbell on the hooks or needing to raise up on their toes to attain clearance). Range 2 position was 4.45 cm below Range 1 and so on and so forth down to Range 7. As outlined, the subjects started at Range 1 and finished at Range 7 at the end of the 7-week training period. Pictures of this set-up are available in Figure 3.
The participants who performed PMT BSQ were instructed to start every repetition from a dead stop, with the barbell resting on the power rack safety arms. They were also instructed to lower the barbell gently to the safety arms (as much as was possible) during each repetition. Short rests between the final repetitions in a set were allowed, but if the athlete had to rest for more than approximately 5-seconds before beginning another repetition, they were instructed to terminate the set and to record the number of repetitions completed. Volume for each working set was not specified by a set number of repetitions, but rather by effort. The participants were instructed to complete as many repetitions as possible for each working set until near exhaustion (about 95% effort). A 95% effort was described to the participant as the point at which they felt that they had a 50% chance of completing a final repetition, or approximately 1 repetition short of failure. Movement specific warm-ups consisted of four sets of progressively heavier loads for 10, 8, 6, and 4 repetitions, respectively. Weight used for each set was approximately 50%, 62.5%, 75%, and 87.5% of the prescribed work-set load, respectively.
To promote the formation and maintenance of a proper braced position, the subjects in the PMT group were instructed to begin each set with the barbell resting in the J-hooks, just like they would with a traditional set of FROM squats (see Figure 3). From this position the participant walked the weight backwards and lowered the weight under control to the safety arms before beginning their first repetition. Participants were instructed to replace the weight back on the J-hooks following each set, but in the event they were unable to replace the weight, they were instructed to leave the barbell resting on the safety arms to be unloaded, placed back on the J-hooks, and then reloaded prior to beginning their next set.
Participants in both groups were given a handout each day with their prescribed workout loads and space to record their workout results. Participants were asked to record completed sets and repetitions, missed workouts, and any changes in, or deviations from, prescribed loading (i.e. % 1-RM). The PMT group recorded the specific Range height and the repetitions they completed during each set. The weight training coach collected the handouts each day.
Following the 7-week training program and between 48-72 hours after the last training session, each participant’s body weight, 1 RM FROM BSQ, and VJ height was reevaluated.
The dependent variables in the study were VJ height (cm), PO (Watts), and the 1-RM FROM BSQ. The Lewis Formula (8) was used to calculate PO (Watts). Dependent variables were compared prior to and following the RT intervention period within experimental groups using paired t-tests. Gain scores were calculated for each dependent variable and compared between the experimental groups with independent t-tests. Effect size (ES) differentials were also calculated for each dependent variable for both experimental groups. Significance was set a priori at α<0.05. Statistical analysis were conducted in an MS Excel spreadsheet that was peer reviewed as previously recommended (1).
Thirty-six male high school students who were enrolled in a weight training class (n=15 in the FROMRT group and n=21 in the PMT group) completed the study. Subject demographics can be found in Table 1. Statistical information describing the pre-post study measures for 1-RM FROM BSQ, VJ, and lower body PO are provided in Tables 2 and 3. Data from three participants was excluded from statistical analysis due to insufficient documentation (they failed to show at least 80% compliance to their assigned program). Two of these participants were in the FROMRT group and one was in the PMT group. Lack of compliance in the case of these three individuals was likely due to forgetfulness and to the fact that failure to complete the study held no consequence.
Table 1: Participant Descriptive Information
|Group||N||Age (years)||Height (cm)||Mass (kg)|
|PMT||21||17.4 ± 0.7||174.9 ± 5.8||84.7 ± 26.5|
|FROMRT||15||17.3 ± 0.7||175.9 ± 8.8||82.1 ± 14.9|
Note: mean±SD, Progressive Movement Training (PMT) and Full Range of Motion Resistance Training (FROMRT)
Table 2: Dependent Variables: Back Squat and Vertical Jump
|1-RM Back Squat (kgs)||Vertical Jump (cm)|
|PMT||96.0 ± 37.8||110.6 ± 37.0*||14.5 ± 9.5||55.8 ± 8.0||59.4 ± 9.5*||3.6 ± 4.3|
|FROMRT||91.3 ± 23.3||102.3 ± 19.4*||11.0 ± 7.6||59.3 ± 9.8||60.7 ± 10.6||1.4 ± 4.3|
Note: Mean±SD. Progressive Movement Training (PMT) and Full Range of Motion Resistance Training (FROMRT). *Significant improvement pre to post intervention p<0.05.
Table 3: Dependent Variable: Power Output
|Power Output (W)|
|PMT||1365.8 ± 410.7||1417.2 ± 394.7*||51.4 ± 63.2|
|FROMRT||1359.3 ± 203.9||1397.1 ± 221.8||37.8 ± 74.7|
Note: Mean±SD. Progressive Movement Training (PMT) and Full Range of Motion Resistance Training (FROMRT). *Significant improvement pre to post intervention p<0.05.
The purpose of this study was to compare the effects of two RT styles, namely PMT and FROMRT, on lower body muscular strength and power following a 7-week training period. Results indicated that both PMT and FROMRT groups significantly improved 1-RM BSQ (p<0.05). The PMT group also significantly improved VJ and PO (p<0.05); however, there was no significant difference in gain scores for any of the dependent variables between the PMT and FROMRT groups (p>0.05). The average BSQ scores assessed in the current study ranked in the 10th percentile (low) for 16-18-year-old high school football players (3). The average VJ scores for each group were considered as “above average” (6) for 16-19-year-old males.
Fundamentally PMT is a form of partial ROM RT, but by increasing ROM of the exercise over time, PMT progresses to a FROM movement towards the end of a RT block. Current literature comparing partial and FROM RT supports the efficacy of both styles for increasing strength and power, with some literature seemingly favoring the effectiveness of one RT method over the other. During a 10-week squatting program Hartmann et al. (9) found deep BSQs to be superior to partial ROM BSQs for improving jumping performance. The groups who performed BSQs with a FROM had significantly higher countermovement jump scores, squat jump scores, maximum voluntary contraction scores, and maximal rate of force development compared to the quarter squat and control groups. In a similar study, Weeks et al. (22) found no difference in VJ improvement while observing 21 subjects who practiced six weeks of BSQs either to 135 degrees, 90 degrees, or to parallel. Bazyler et al. (4) performed another BSQ study and concluded that combining full and partial ROM squats improves maximal strength in men with previous training experience and use of partial ROM squats may be appropriate for strength and power athletes during a strength-speed mesocycle or while peaking for competition. Upper-body studies by Massey et al. (15), and by Pinto et al. (18), found partial ROM and full ROM RT equally effective for increasing strength. Based on the current literature it appears that partial ROM RT protocols may be effective for enhancing muscular strength and power, while FROM RT protocols are definitively effective. With that said, scientific literature documenting the effectiveness of PMT RT protocols is absent.
Tsatsouline (21) speculates “neurological carryover” as a mechanism for the purported effectiveness of PMT. Neurological carryover is a concept based upon a principle commonly applied to isometric training known as joint-angle specificity. Fleck and Kraemer (7) defined joint-angle specificity as “gains in strength [that] occur predominantly at or near the joint angle at which isometric training is performed.” Multiple studies have shown that strength gains resultant from isometric training are highly specific to the joint angle that is exercised (11, 20, 23-24). For example, performing an isometric exercise for the BSQ with the knee joint almost completely extended (near lock out), would have almost no carryover towards facilitating an athlete’s strength out of the bottom of a BSQ. However, the consensus of multiple studies on joint angle specificity is that a carryover of strength occurs to joint angles varying from 5 to 30 degrees on either side of the joint angle isometrically exercised, with the variance in strength carryover being dependent upon the muscle group (i.e. tricep surae vs quadriceps vs elbow flexors and extensors) and joint angle (e.g. acute vs obtuse) trained (7, 11, 12, 14, 20). Due to the limited increase in muscular size resultant from isometric training, much of the strength gained during isometric exercise programs has been attributed to neurological adaptations (11). Although no known studies have reported a similar strength carryover during partial ROM exercise, it seems plausible that such a strength carryover could occur during PMT. Interestingly, the term “neurological carryover” referred to by Tsatsouline (21) suggests the idea that strength gains resulting from PMT are likely due to neurological adaptions. The start of every repetition in a PMT RT program is a submaximal isometric contraction (up until enough force is produced to move the load), and if failure is reached, the contraction following an effort to complete another repetition is isometric, therefore, neurological strength carryover could be one mechanism by which PMT improves measures of muscular strength and power. Although joint angles about the knee were not measured during this study, it seems likely that the 4.45 cm incremental linear changes in ROM that were prescribed were small enough to equate to changes in joint angles ranging from 5-30 degrees. Hence, as the participant progressed from one safety arm position to the subsequent position (4.45 cm lower), there may have been a strength carryover attributed to the RT that was conducted at the previous safety arm position during the prior week. As such, a carryover of strength from one safety arm position to the subsequent position that may occur as a result of PMT RT may be similar to that observed as a result isometric RT programs.
The results of our study indicate that both PMT and FROMRT significantly and similarly increase muscular strength, however, only PMT resulted in significantly higher VJ and PO scores from the pretest to the posttest. Despite the significant increase in VJ height and PO measured in the PMT group, no significant differences in gain scores between the PMT and FROMRT groups were found for any of the dependent variables (p>0.05). These results are in partial agreement with aforementioned studies of partial ROM RT and FROMRT (18, 15, 22). It is unclear whether or not neurological carryover played a role in the effectiveness of PMT, but the principle does seem to help explain how participants were able to continue to move a supramaximal load after increasing ROM seven times throughout the study duration. Similar to overcoming isometric resistive forces, we speculate that the creation of high levels of force at joint angles similar to those required during the VJ test may have contributed to the significant increases in VJ height and PO observed in the PMT group. Peer-reviewed literature regarding PMT is to our knowledge nonexistent. However, literature on related topics, including comparisons between partial ROM RT and FROMRT (4, 9, 22), and a principle known as joint angle specificity (11-12, 14, 20) (most commonly applied in isometric exercise research) should be considered to better understand the mechanistic nature of PMT’s efficacy.
The primary limitation of this study is the lack of existing PMT RT programs or protocols. As such, there was some ambiguity in the PMT RT protocol that was not present in the FROMRT programming. Due to this discrepancy, it is possible that any statistical variance between the RT groups was influenced by program volume (workload) rather than differences in RT modality. Additionally, the squat racks used in our study had fixed increments for the rack safety arms (≈8.89 cm apart) that established the ROM for each Range in the PMT protocol. As a result, the ROM was adjusted incrementally by the same distance for all athletes, regardless of body height, so subsequent vertical barbell displacement may not have been sufficiently controlled. Finally, the sample used for this study may also represent a limitation. Male high school students were recruited based on convenience and ease of program implementation; however, using novice high school students prevented the full prescription of PMT RT programming as originally described (2). Although purely speculative, according to Anderson (2), frequent training sessions (>4 per week) with supramaximal loads may help to desensitize inhibitory neural signals during near maximal muscular contractions. However, for the novice, adolescent participants of this study, a training frequency greater than three times per week was deemed unsafe, therefore, inadequate training stimulus may have prevented optimal desensitization of neural inhibition.
The PMT RT programing used in the current study was shown to be effective and appropriate for the participant population, however we speculate that future research could lead to more optimal RT protocols and a consequent increase in efficacy. Future research may focus on variances in training populace as well as varying exercise frequency, load, and duration. Finally, other potential benefits of PMT should be explored; these include but are not limited to improvements in RT technique, functional mobility, and hypertrophy, as well as use of PMT as a rehabilitation technique for injured athletes.
The purpose of this study was to determine if a PMT RT program would improve lower-body muscular strength and power, as measured by the 1-RM FROM BSQ, maximum height VJ, and PO to a greater degree than a periodized FROMRT program. Based on study findings, PMT did not improve lower-body muscular strength and power to a significantly greater degree than FROMRT, however, it did induce significant increases in all three DVs. These results indicate that PMT RT could be at least as effective as FROMRT for improving lower-body muscular strength and power. The PMT RT protocol and modality used in the current study, to our knowledge, was novel. Future research may use the methods of this study as a model for the design of other PMT RT protocols. Finally, given that PMT RT was as effective as the FROMRT, strength and conditioning professionals now have an additional tool to design effective variability in RT protocols.
APPLICATIONS IN SPORT
Our research supports the effectiveness of PMT as a RT method used to develop muscular strength and power. In the strength and conditioning sphere, PMT can be used as another training option for coaches to employ during certain training blocks. It seems that PMT may be useful as a strength builder for foundational strength exercises during brief training blocks where strength development is of primary importance. Though beyond the scope of this particular study, we speculate that PMT may also be a useful training option for coaches working with tall or otherwise “positionally challenged” athletes and persons who struggle to perform core exercises through a full ROM. PMT may help athletes to develop gradually functional mobility while simultaneously building strength and power. PMT may help individuals suffering from joint immobility or other contracture to develop gradually a healthier range of motion. For this reason, PMT may also become a useful RT method to implement in rehabilitative settings.
We would like to thank Coach Ollie Whaley and the students from Monument Valley High School for their help and participation during this research project.
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