The Influence of Periodized Resistance Training on... : The Journal of Strength & Conditioning Research (original) (raw)
Introduction
Low back pain (LBP) is a health issue most people will experience in their lifetime (5,34). In older adults with LBP only 15% will receive an accurate pathoanatomical diagnosis, making the most common diagnosis chronic nonspecific low back pain (CLBP) (5,34). Some have suggested that LBP is associated with reduced fitness (46). However, for those who participate in sports, the high physical demand may also increase the risk of LBP, with CLBP being more common in the older athlete (5,42). Thus, CLBP effects a wide population of people both physically active and inactive.
The disability associated with CLBP often reduces quality of life (QoL) (32), which may result from increased pain and the fear-avoidance cycle that frequently follows the onset of pain (12,49). In contrast, an increase in physical activity and fitness is shown to decrease pain and disability and improve QoL (12). To improve QoL and reduce CLBP, exercise therapy is suggested as a viable rehabilitation (21). Numerous forms of exercise therapy have been prescribed for those with CLBP, such as physiotherapy, back schools, muscle reconditioning, aerobic exercise, and stretching classes to cite a few (22,27,28,34). Generally, exercise therapy is considered a promising method of rehabilitation (21), 1 form of which is resistance training. Resistance training has been scientifically investigated since the 1950s and was used as a form of rehabilitation post-World War II (11). The basis of this rehabilitation is to progressively overload the specific muscle group(s) that require(s) rehabilitation or improvement in muscular strength, endurance, hypertrophy, and so on. This concept is still used today.
A related concept is that of periodization, which is a variation in training volume, intensity, and specificity by breaking the year into specific time periods (3). The division of the year into time periods allows each period to have a specific focus (e.g., strength). In each subsequent period the focus shifts to another physical attribute, technique, and so on. This form of organization for physical training has been used in the physical preparation of athletes for many years (36). However, recently it was applied to exercise therapy, such as resistance training for those with musculoskeletal injuries such as CLBP.
Whole-body periodized resistance training was revealed to be an effective method of CLBP rehabilitation (26). To date this is the only study to address CLBP with periodized exercise rehabilitation. The rationale for the application of periodization to the rehabilitation setting was based on the previous research (26) and the idea that the rehabilitation of a chronic musculoskeletal condition is not very different from attempting to improve a musculoskeletal deficiency in a novice athlete. Both situations (i.e., persons) have 1 or more specific deficiencies that must be improved, and the application of progressive overload, specificity, and variation in a periodized framework is a reasonable answer to the problem.
The present study used a periodized resistance training (PRT) program as a form of CLBP rehabilitation, but in this case the program was applied to a homogeneous group of middle- to old-aged male hockey players with CLBP. Thus, the subjects were already physically active (moderate level) in a sport demanding aerobic power and muscular strength (41) but still expressed CLBP. As previous results indicate, PRT was effective in the treatment of CLBP in untrained persons (26); thus, the purposes of the current study were to determine (a) the effectiveness of PRT at increasing strength and reducing pain, disability, and improving QoL in recreationally active males with CLBP; and (b) if the effect of the PRT program was age dependent. We hypothesized that PRT would produce a statistically significant improvement in muscular strength, pain, disability, and QoL, with age being of no influence.
Methods
Experimental Approach to the Problem
Recently, it was demonstrated that PRT was beneficial at improving strength and reducing CLBP symptoms in untrained (sedentary) young and middle-age males and females (26). The present study was an extension of the aforementioned study, with the purpose of determining the effectiveness of PRT at increasing strength and reducing CLBP symptoms in active (moderately trained) middle- and old-age males and whether the responses of the 2 age groups are similar in magnitude (i.e., percent change). The subjects in this study participated regularly in ice hockey and other recreational activities (e.g., jogging), excluding formalized resistance training, but they still suffered from CLBP. Previous research had determined periodized resistance training to be an effective rehabilitation for sedentary persons with CLBP (26). Thus, the purpose of this study was to establish the effectiveness of 16 weeks of PRT in the rehabilitation of a moderately trained middle- and old-age males with CLBP. Their progress was measured using 5 repetition maximum (5RM) testing and scores on pain, disability, and general health surveys at baseline and at weeks 8 and 12. The PRT program aimed to maximize strength gains by progressively overloading each muscle group throughout the 16 weeks. The exercise type, exercise order, sets, repetitions, rest time, exercise days, and volume and intensity were identical in both the ME and OE groups.
Subjects
The study met the approval of the Faculty of Education, Extension and Augustana Research Ethics Board at the University of Alberta for the use of Human Subjects. Subjects were recruited via advertisement from the province of Alberta. All interested subjects contacted the researcher, and those that met the eligibility criteria were included in the study. Eligibility for participation included males ≥45 years of age with chronic (≥3 month, ≥3 days·week) nonspecific (soft tissue) low back (lumbar 1 to 5) pain (visual analog pain scale ≥3) as diagnosed by a physician. Thus, the pain is associated with the soft tissue (i.e., ligaments, tendons, muscle) of the low back region. They also must play recreational ice hockey. The occupation of the subjects or any work-related information (e.g., Workers' Compensation Board claims) was not used as an inclusion or exclusion criteria because some subjects were retired. The subjects' CLBP had not been relieved by bed rest or conventional medical interventions (e.g., physiotherapy, back school), they were not undergoing any medical interventions at the time of the study, and they were asked not to begin any medical interventions during the course of the study. The mean duration of pain was 23.1 months (range 8-76 months). The most common symptom reported by the subjects was dull, nagging pain and muscle stiffness in the low back region. Potential subjects were excluded from participation if they had been diagnosed by a physician with any of the following: pain below the knee, spinal stenosis, herniated or ruptured disc(s), spondylolisthesis, infection in the lumbosacral area, tumor(s), scoliosis, rheumatologic disorder, osteoporosis, or history of previous back surgery. Also, any subjects with a medical history of metabolic, endocrine, cardiovascular, or neurological disease were excluded from participation (2). The subjects read the information letter, asked questions of the researcher, and completed an informed consent form and a physical activity readiness questionnaire (PAR-Q). All subjects gave their free and informed consent.
The Godin Leisure-Time Exercise Questionnaire (GLTEQ) indicated that the subjects were in a moderately trained state (mean 13.2, range 6-22) (15), participating in recreational ice hockey for 60 minutes (min) 2 times·wk−1, ∼5 months·yr−1, for ≥7 years (years). The subjects were also active in other recreational activities (e.g., curling, walking, swimming) ∼2 days·wk−1 but were not active in resistance training (i.e., strength training). Following baseline testing the 45 male subjects were randomly assigned to 1 of 3 groups based on age. The groups were (a) ME (n = 15; age = 52 ± 2.7 years; height = 1.77 ± 0.06 m; body mass = 80.2 ± 3.4 kg; percent (%) body fat = 24.4 ± 3.6%); (b) OE (n = 15; age = 63 ± 3.1 years; height = 1.75 ± 0.08 m; body mass = 76.5 ± 2.9 kg; % body fat = 27.3 ± 2.8%); or (c) control (C) (n = 15; age = 57 ± 7.7 years; height = 1.76 ± 0.07 m; body mass = 77.9 ± 4.1 kg; % body fat = 25.6 ± 3.9%). The subjects randomly assigned to the C group demonstrated the same symptoms and met the same inclusion and exclusion criteria. The C group was a combined group that consisted of both middle-and old-age males. There were no significant (p ≤ 0.05) differences within group over time in body mass and % body fat. At baseline, week 8, and week 12 there were significant (p ≤ 0.05) differences in body mass, % body fat, and all strength measures among the ME and OE groups, but no significant (p ≤ 0.05) differences were noted between the C vs. ME or OE groups on the same variables. However, group differences in body composition and absolute strength were not of interest in this study. Of interest were within-group changes in outcome measures across time and percent (%) change (improvement) from baseline to week 12 between groups. There were negative side effects (e.g., increased back pain) from participation in the study. Five subjects dropped out for various reasons (e.g., other time commitments); these subjects' data have been excluded from analysis.
Design
The total study duration was 16 weeks, with 3 weeks of familiarization and 13 weeks of testing and PRT (Table 1). The subjects were given verbal and written instructions (with illustrations and video) addressing exercise technique, warm-up, cool-down, and proper exercise attire. Subjects were permitted to complete their PRT program at a fitness facility near their residence; thus, the brand of fitness equipment was not consistent between subjects. Most resistance equipment used in the study were (a) Atlantis Strength Equipment (Laval, QC, Canada), (b) Life Fitness (Schiller Park, Illinois, U.S.A.), or (c) Body-Solid equipment (Forest Park, Illinois, U.S.A.), which allowed a full range of motion, smooth action, and easy pin adjustment of the load. However, all other training variables were consistent between PRT groups (OE and ME), exercise type, exercise order, sets, repetitions, rest, exercise days, and volume and intensity.
Study timeline and weekly volume and intensity.
The familiarization period was used to acquaint the subjects with the (a) repetition maximum protocol, (b) exercise movements (e.g., neuromuscular control), and (c) exercise order. This period used the same exercises, exercise order, and rest time as used in the PRT period of the study. The primary differences between the familiarization and PRT periods were the training volume and intensity. The volume and intensity were substantially less in the familiarization period to allow the subjects to anatomically adapt to the resistance training program. Both volume and intensity were set to a comfortable level to help prepare the muscles, ligaments, tendons (soft tissue), and joints for the more demanding and strenuous training in the PRT period.
In week 1 of the familiarization, the subjects completed a 5RM test on exercises #1 to 10 (Table 2). The initial testing session determined the load in kilograms on each resistance exercise for the next 2 weeks of (familiarization) training. Weeks 2 and 3, familiarization training, consisted of resistance training using 2 sets of exercises #1 to 10, 55 to 60% of 1RM, 10 to 12 repetitions per set−1, and 1-minute rest between sets and exercises (Tables 1 and 2). Five RM testing was not conducted on abdominal (Ab) or low back exercises (i.e., core area exercises; #11, 12, 13). The subjects were instructed to complete 30 consecutive repetitions on the abdominal exercises (Table 2, #10, 11). Once the subjects could complete 30 repetitions, they added resistance (holding a free weight on their chest) and worked toward achieving 30 repetitions and then increased the resistance again. The prone superman was body-weight resistance only, 10 repetitions each set, with the isometric contractions held from 5 to 30 seconds (s)·repetition−1. The progressive overload was administered by increasing the duration of the isometric contraction up to 30 seconds. At the conclusion of the familiarization period the C group subjects stopped all resistance training. The C group was allowed to continue with their regular recreational activity schedule, but they could not start any new form of physical activity. Once the study was complete, the C group subjects were provided with a 12-week PRT program on their request, with the intent of providing the same benefits to the C subjects as the others.
Workout and exercises specifics.
Following the familiarization period was baseline testing, which set the loads for each resistance exercise in the PRT program for the next 3 weeks. This pattern was repetitive over the remaining 9 weeks (Table 1). The purpose of the PRT program was to systematically and progressively overload each muscle group to maximize strength gains in a safe and effective manner (for details see Tables 1 and 2). The training program was a traditionally periodized, 4 day·wk−1, split-routine design, exercising upper-body, lower-body, and core area exercises on different days. They completed 3 to 6 sets·exercise−1 on Monday, Tuesday, Thursday, and Friday. All outcome measures were completed at baseline, week 8, and week 12 testing sessions. The outcomes measures were changes in strength (kg), body mass (kg), body composition (% body fat), pain, disability, and QoL.
Procedures
Body composition and anthropometric measures were standing height (m), body mass (kg) and % body fat. Measurements were taken in the field at designated locations in or near the communities of the subjects. Standing height was measured with a metric wall tape, set square and wooden board (nearest 0.5 cm). Body mass and composition was measured on a Tanita BF 300A (bioelectrical impedance) body composition scale to the nearest 0.1 kg and 1% body fat. Body composition measurements were performed at the same time of day with the subjects having clean bare feet and same hydration level to ensure validity and reproducibility (45).
The bench press, leg press, and lat pulldown used a 5RM effort determined within 4 sets, including one warm-up set followed by 3 challenging sets of increasing load (kg) (3). The rest time between each set was 2 minutes. The free-weight bench press was conducted on a flat bench with an Olympic style bar and weights. Its purpose was to determine upper-body strength. The subjects were instructed to position themselves supine on the bench press, grasp the bar with hands approximately shoulders-width apart, and extend their arms at the elbow removing the bar up off the supports. The bar was then lowered (under control) to the chest and then in a smooth motion pushed back up, extending the elbows returning to the starting position. Lowering the bar to the chest and then pushing the bar back up to the start position was considered 1 repetition of that exercise; this was repeated 5 times (repetitions). The leg press test was conducted on a standard sled leg press machine with Olympic style weights; it should be noted that the weight of the sled was not included. The purpose was to determine lower-body strength. The subject sits on the machine, back on the padded support and feet placed shoulder-width apart on the platform. The sled was then pushed up, the safety handles unlocked, and the support handles grasped. The sled was lowered (under control) to just short of complete flexion (∼45-degree angle at the knee joint) and then in a smooth motion pushed back extending the knees and hips, returning to the starting position. Lowering the sled just short of complete flexion and then pushing the sled to the start position was considered 1 repetition of that exercise and was repeated for 5 repetitions. The lat pulldown test was conducted on a standard lat pulldown machine. Its purpose was to determine the upper-body strength of the back muscles. The subject sat on the padded seat with feet flat on the floor and knees tucked under the padded support. Hands were placed just outside of the bends in the pulldown bar (∼4 inches wider than shoulder width). The bar was pulled down to the chest smoothly by flexion of the elbows and adduction at the shoulders, then returned to the start position in a controlled motion. Pulling the bar to the chest and returning it to the start position was considered 1 repetition of that exercise; 5 repetitions were executed.
Subjects finished pain, disability, and general health surveys at baseline, week 8, and week 12. The surveys included visual analog scale (VAS), the Oswestry Disability Index (ODI), and the Short-Form 36 Health Survey (SF-36). The VAS is a visual scale used to measure how much back pain the person felt during a typical week (0 = no pain; 10 = maximal pain) (25). The ODI is a disease-specific measure used in the management of spinal disorders (0 = no disability; 100 = maximum disability) (13). The SF-36 is a measure of general health status (QoL) that contains 36 items, which breaks down into 8 domains: physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role, and mental health (7). The domains are scored on a scale from 0 (worst possible health) to 100 (best possible health). The physical functioning domain contains 10 items that evaluate physical activity limitations (e.g., walking). The role of the physical and emotional domains is to evaluate occupational or daily activity problems that result from physical or emotional health problems. Bodily pain assesses limitations resulting from pain, whereas vitality measures energy and fatigue. The social functioning domain measures the effect of physical and emotional health on normal social activities. Mental health assesses happiness, nervousness, and depression. The general health perceptions domain evaluates personal health and the expectation of changes in health. From the 8 parameters, 2 composite scoring summaries can be derived: (a) Physical Composite Summary (PCS: physical functioning, role physical, bodily pain, and general health perceptions) and (b) Mental Composite Summary (MCS: vitality, social functioning, mental health, and role emotional), such as problems at work of other daily activities as a result of emotional problems (50).
Statistical Analyses
All values were reported as mean and SD (mean ± SD) or % change. Age, height, body mass, body fat, bench press, lat pulldown, leg press, VAS, ODI, and SF-36 (PCS and MCS) were assessed via a repeated-measures analysis of variance (ANOVA) to measure changes within the ME, OE, and C groups from baseline to week 8, week 8 to week 12, and baseline to week 12. Percent change was calculated as follows: % Improvement = [(posttest group mean - pretest group mean) ÷ (pretest group mean)] × 100. In variables where a decrease in the posttest score demonstrated improvement (VAS and ODI), the calculation was completed as follows: % Improvement = [(pretest group mean - posttest group mean) ÷ (pretest group mean)] × 100; this would allow for a positive number in the outcome (result). The calculation of effect size was carried out as follows: (experimental group mean - C group mean) ÷ SD of the C group. A Pearson's product moment correlation coefficient (correlation; r) was conducted to determine the ability of changes in strength to predict changes in pain and disability. A Levene's test for homogeneity of variances was completed on each dependent variable during the ANOVA, and in each case, homogeneity of variance was found. To assess test-retest reliability, intraclass correlation coefficients (ICC) comparing baseline to week 12 were completed using the C group data on the following dependent variables: bench press, leg press, lat pulldown, PCS, and MCS (51). The results demonstrated a mean ICC of 0.90 and a range of 0.81 to 0.95. Statistical power was determined to range from 0.75 to 0.80 for the sample size used with the outcome measures in this study. All differences were considered significant at an alpha of 0.05 (p ≤ 0.05).
Results
Muscular Strength
At baseline the ME group was significantly stronger than the OE group on bench press, lat pulldown, and leg press (Table 3). This remained consistent throughout the duration of the study, but between-group differences in absolute strength were expected as a result of age; thus, group comparisons in absolute strength were not made.
Changes in muscular strength following 4 days·wk−1 of resistance training.
In contrast, the ME and OE groups made similar improvements in strength over time (Table 3), whereas the C group demonstrated no significant change in strength across time. The ME and OE groups demonstrated statistically (p ≤ 0.05) significant increases in strength (i.e., bench press, lat pulldown, and leg press) from baseline to week 8, baseline to week 12, and week 8 to week 12 (Table 3). Strength improvements in the OE group showed clinical significance (≥25% change) from baseline to week 12 on bench press, lat pulldown, and leg press, whereas the ME group demonstrated near clinical significance on the lat pulldown, leg press, and bench press (Table 4). Significant (p ≤ 0.05) differences were found between the ME and OE groups on % change in bench press and lat pulldown strength but not leg press strength (Table 4).
Percent change in muscular strength, pain, disability, and quality of life from baseline to week 12.
It is worth noting that significant correlations were found when comparing % change in bench press strength with % change in pain (r = 0.80; 64% of the common variance) and disability (r = 0.77; 59% of the common variance). Significant correlations were also noted when comparing % change in leg press with % change in pain (r = 0.71; 50% of the common variance) and disability (r = 0.72; 52% of the common variance). Thus, between 50 and 64% of the change in pain and disability can be explained by changes in upper- and lower-body strength as measured by bench press and leg press.
Pain, Disability, and Quality of Life
At baseline there were no significant (p ≤ 0.05) differences between the ME, OE, and C in pain, disability, and QoL measures (Table 5). At weeks 8 and 12 the intervention groups showed significant (p ≤ 0.05) improvements in pain, disability, and QoL measures as compared to the C group. However, there were no significant (p ≤ 0.05) differences between the ME and OE groups at weeks 8 and 12 in pain, disability, and QoL.
Changes in pain, disability, and quality of life following 4 days·wk−1 of resistance training.
Both the ME and OE groups showed statistically significant (p ≤ 0.05) improvements in scores from baseline to week 8, baseline to week 12, and week 8 to week 12 (Table 5). By the conclusion of the study, both the ME and OE groups demonstrated significantly (p ≤ 0.05) less pain and disability and improved QoL scores as compared to the C group. When comparing baseline to week 12, the results for the ME group were clinically significant (≥25% change) for pain, disability, and the physical composite (xz)of QoL (Table 4). The ME group did not show clinical significance on the mental composite (xz) of QoL. The OE group showed clinical significance (≥25% change) on pain, disability, and the mental composite (xz) of QoL. The OE group did not show clinical significance on the physical composite (xz) of QoL. Significant (p ≤ 0.05) differences in % change on disability, PCS, and MCS were found among the ME and OE groups, but no significant (p ≤ 0.05) difference was found on % change in pain (Table 4).
Discussion
The 16-week PRT program resulted in significant (p ≤ 0.05) changes in most of the outcome variables (strength, pain, disability, and QoL). Both ME and OE groups demonstrated similar increases in strength to healthy males of the same age. The ME and OE groups responded similarly in magnitude to PRT, with improved strength, reduced pain and disability, and improved QoL. Thus, age did not influence strength grains, as determined by % change from baseline to week 12. These findings demonstrate that PRT is beneficial for moderately trained, recreationally active middle- and old-age males who suffer from CLBP and adds to the body of evidence that suggests that strength training is beneficial for those with CLBP. More specifically, the findings indicate that PRT may be more effective than other forms of musculoskeletal strengthening at addressing CLBP.
Previous research has shown that resistance training results in improved muscular strength in healthy young adults (1) and healthy older, sedentary adults (18,33). Resistance training in older adults improves neuromuscular control; bone mineral density; muscle cross-sectional area, strength, and power; and functional abilities (16,18,19). Strength gains that occur in the first 8 weeks of strength training (e.g., PRT) are associated with neurological adaptations (17), motor coordination, and motor unit synchronization (4). Strength improvements following the initial 8 weeks are typically related to increased muscle anabolism (i.e., hypertrophy) (17). The duration of the current program (16 weeks) was likely sufficient to realize improvements in strength that resulted from both neuromuscular and hypertrophic changes. Although the ME and OE groups did not show a significant (p ≤ 0.05) change in body composition over the 16 weeks, suggesting that the changes in strength may be more closely associated with neuromuscular adaptations.
Research from this lab, and others, has also demonstrated that an untrained person with CLBP can benefit from resistance training (26,35,37). Based on the aforementioned studies, we wanted to determine if middle- and old-aged moderately trained, recreational athletes (ice hockey players) suffering from CLBP would also benefit (e.g., increased strength and reduced pain) from periodized resistance training.
The present study's results strongly indicate that PRT can improve strength and reduce CLBP symptoms even in persons that are currently active (moderately trained) in a sport that requires a mixture of aerobic fitness and muscular strength (41). Strength gains were similar to those seen in healthy subjects of various ages (1,8). When the effect size is calculated for bench press (ME = 3.3; OE = 2.1), lat pulldown (ME = 5.0; OE = 1.5), and leg press (ME = 3.1; OE = 1.3), the results indicate that the ME and OE groups exceeded the effect sizes outlined for both the trained and untrained groups in the meta-analysis by Rhea and Alderman (untrained = 1.59; trained = 0.78) (43). Moreover, if we then compare the ME (effect size = 3.8) and OE (effect size = 1.6) groups based on age, it is evident that the effect size for both groups exceeded those found by the Rhea and Alderman study (<55 years = 1.34; >55 years = 0.85) (43). Thus, even though the ME and OE subjects were moderately active (a variety of recreational activities) and trained (ice hockey), the strength improvements were statistically and clinically significant. This finding is likely the result of either the PRT program being highly effective, or subject error in the completion of the GLTEQs.
If the improvements in strength are a result of the PRT program, it is likely via the manipulation of the program variables, just as it is in training programs for recreational and high-performance athletes. It is the manipulation of these program variables (and concepts) that make the program(s) effective; such variables include training frequency, load, exercise order, exercises performed, number of repetitions, progressive overload, and overall volume and intensity. The researchers carefully considered the aforementioned variables when designing the PRT program so that it would be safe and effective for the rehabilitation of recreationally active CLBP subjects.
Periodization manipulates physical stress and recovery time by adjusting the volume and intensity of training (overload principle), which facilitates important musculoskeletal adaptations (e.g., neuromuscular) (40,44). This study's program design was of a traditional periodized (linear) nature, manipulating volume and intensity over the 16 weeks of training. Following the familiarization phase, the volume was gradually increased, as was intensity, but in the final 3 weeks the training volume was substantially reduced while the intensity likewise increased (Table 1). The workout sessions were organized to move from large muscle mass exercises (multijoint, primary) to smaller muscle mass exercises (single-joint, assistance). The intensity progressed from a low-intensity, familiarization phase (2 weeks, 4 days·wk−1, 55-60% 1RM) to a higher-intensity, strength phase (12 weeks, 4 days·wk−1, 60-83% 1RM). The initial 2-week familiarization period also acted as an anatomical adaptation phase, which we suspected would reduce delayed onset muscle soreness (DOMS) (26) and develop a training base to reduce burnout in the subjects (8). The program was designed as a split routine with chest, back, triceps, and core area exercises on Monday and Thursday and legs, shoulders, biceps, and core area on Tuesday and Friday. The split routine was selected because it provided the advantage of applying a higher intensity and volume of training, which is known to enhance strength gains (14). Typically, periodized strength training studies have implemented a 3 day·wk−1 training schedule (4,8,40), but the current PRT program used a 4 day·wk−1 schedule. This decision was based on previous research that suggested that a 4 day·wk−1 schedule would effectively develop strength in those with back pain (26) and is the preferred off-season training schedule of high-performance athletes (23). These characteristics were essential to the development of strength in the CLBP subjects (26), just as they are in the physical training and preparation of healthy and athletic populations (30,31).
The inclusion of free-weight exercises was an important characteristic of the PRT program because free-weight exercises are associated with greater work and fatigue in the synergist and stabilizer muscles (29). The reason for the augmented activation and fatigue of synergist and stabilizer muscles was the increased neuromuscular control required to execute proper movement with free weights (47). The free-weight exercises (e.g., bench press) focus on the primary movers (e.g., pectoralis major), but we believe that it is the work of the synergist and stabilizer muscles (e.g., rhomboids) in supporting the primary movers that is important to improving CLBP.
Previous research has shown that exercise is beneficial to CLBP (21), with some research implementing muscle-strengthening programs with mixed results (6,9,10,20,26,35,38,39). Many of the strengthening programs that focused on core area (abdominal and low back) stabilization and endurance demonstrated minimal positive effects (9,10,20,38). In contrast, exercise programs that focused on whole-body muscular strength demonstrated better results (6,26,35,37), and aside from changes in physical function, some programs were able to improve pain and disability (26,35,37).
Potentially, PRT has demonstrated the most significant improvements in strength, pain, disability, and QoL in those with CLBP (26). Based on previous research from our lab, which showed that PRT was effective at improving CLBP in the untrained person, the present study attempted to determine if a similar program (i.e., PRT) would be beneficial to middle- and old-age moderately active recreational athletes who suffer from CLBP. The findings supported our initial hypothesis-that the active CLBP subjects responded similarly to the untrained CLBP subjects, with improved strength, reduced pain and disability, and improved QoL. Similar training-induced changes in strength in middle- and-old age persons has been previously shown (19) but not in persons with CLBP and not using PRT. Moreover, it was revealed that improvements in pain and disability might be associated with improvements in strength derived from PRT.
It was previously suggested that reduced isokinetic strength of trunk extensors may be 1 of the factors related to CLBP (24). Moreover, the current study showed that the % change in both primary upper- (i.e., bench press) and lower- (i.e., leg press) body strength was correlated with both pain (+0.80, +0.71, respectively) and disability (+0.78, +0.72, respectively). The size and significance of these correlations demonstrate their usefulness, and we can conclude that the relationship between these variables is real and not caused by chance (48). The results indicate that changes in strength (i.e., 5RM) may be used to predict changes in pain and disability and that the prediction can be made with both the bench press and leg press exercises. Approximately 50 to 65% of pain and disability was predicted by lower- and upper-body strength. Thus, no special equipment or tests were required to predict pain and disability. Moreover, changes in upper-body strength (bench press) may better predict changes in pain and disability in those with CLBP, as compared to changes in lower-body strength.
In conclusion, this is the only study that has addressed CLBP in middle- and old-age recreationally active male ice hockey players with CLBP. The results demonstrate that PRT programming can improve strength, pain, disability, and overall QoL in this population. This builds on the previous finding that PRT is effective at reducing pain and disability and improving QoL in untrained males and females (26). Thus, this is the first evidence for the use of PRT in the rehabilitation of athletes with CLBP and the association between improved upper- and lower-body muscular strength and reduced pain and disability.
Practical Applications
Our initial study of CLBP and exercise determined that PRT was more effective than aerobic training at reducing CLBP in an untrained population (26), whereas the present study has confirmed the effectiveness of a similar traditionalized PRT program at improving strength and reducing CLBP symptoms in a moderately trained middle- and old-age athletic population. Therefore, a similar traditional periodized framework typically applied in the physical development of a healthy athletic population may be a useful mode of rehabilitation for middle- and old-age athletes with CLBP. We believe that there are 3 key components to consider when designing the PRT program: (a) a short (2-4-week) familiarization/adaptation phase; (b) a mixture of free weights and machines, moving toward more free weights and fewer machines as time progresses; and (c) a 4 days·wk−1 schedule to assure the necessary volume and intensity are applied. However, the most important aspect of applying this program safely is an accurate diagnosis by a physician indicating that the person/patient/client has nonspecific low back pain, meaning soft tissue in origin. We cannot recommend the use of this program, based on the limited research, on persons with any neural, structural, disc, or similar injuries or abnormalities (see exclusion criteria in Methods section).
Acknowledgments
The authors received The University of Alberta, Augustana Campus Research and Travel grant. I am also grateful to Dr. Donald Sharpe for his assistance with the statistical analyses.
References
1. Abe, T, Dehoyos, DV, Pollock, ML, and Garzarella, L. Time course for strength and muscle thickness changes following upper and lower body resistance training in men and women. Eur J Appl Physiol 81: 174-180, 2000.
2. American College of Sports Medicine. Resource Manual for Guidelines for Exercise Testing and Prescription. 4th ed. Philadelphia: Lippincott Williams & Wilkins, 2001.
3. Baechle, TR. Essentials of Strength Training and Conditioning. Champaign, Illinois: Human Kinetics, 1994.
4. Baker, D, Wilson, G, and Carlyon, R. Periodization: The effect on strength of manipulating volume and intensity. J Strength Cond Res 8: 235-242, 1994.
5. Baker, RJ and Patel, D. Lower back pain in the athlete: Common conditions and treatment. Prim Care 32: 201-229, 2005.
6. Bentsen, H, Lindgarde, F, and Manthorpe, R.The effect of dynamic strength back exercise and/or a home training program in 57-year-old women with chronic low back pain. Results of a prospective randomized study with a 3-year follow-up period. Spine 22: 1494-1500, 1997.
7. Brazier, JE, Harper, R, Jones, NM, O'Cathain, A, Thomas, KJ, Usherwood, T, and Westlake, L. Validating the SF-36 health survey questionnaire: New outcome measure for primary care. BMJ 305: 160-164, 1992.
8. Buford, TW, Rossi, SJ, Smith, DB, and Warren, AJ. A comparison of periodization models during nine weeks with equated volume and intensity for strength. J Strength Cond Res 21: 1245-1250, 2007.
9. Carpenter, DM and Nelson, BW. Low back strengthening for the prevention and treatment of low back pain. Med Sci Sports Exerc 31: 18-24, 1999.
10. Danneels, LA, Cools, AM, Vanderstraeten, GG, Cambier, DC, Witvrouw, EE, Bourgois, J, and De Cuyper, HJ. The effects of three different training modalities on the cross-sectional area of the paravertebral muscles. Scand J Med Sci Sports 11: 335-341, 2001.
11. Delorme, TL and Watkins, AL. Technics of progressive resistance exercise. Arch Phys Med Rehabil 29: 263-273, 1948.
12. Demirel, R, Ucok, K, Kavuncu, V, Gecici, O, Evcik, D, Dundar, U, Solak, O, and Mollaoglu, H. Effects of balneotherapy with exercise in patients with low back pain. J Back Musculoskel Rehab 21: 263-272, 2008.
13. Fairbank, J, Pynsent, P, and Disney, S. The Oswestry Disability Index. 2006.
14. Fleck, SJ and Kraemer, WJ. Designing Resistance Training Programs. 2nd ed. Champaign, Illinois: Human Kinetics, 1997.
15. Godin, G and Shephard, RJ. A simple method to assess exercise behavior in the community. Can J Appl Sport Sci 10: 141-146, 1985.
16. Häkkinen, A, Pakarinen, A, Hannonen, P, Kautiainen, H, Nyman, K, Kraemer, WJ, and Häkkinen, K. Effects of prolonged combined strength and endurance training on physical fitness, body composition and serum hormones in women with rheumatoid arthritis and in healthy controls. Clin Exp Rheumatol 23: 505-512, 2005.
17. Häkkinen, K. Neuromuscular and hormonal adaptations during strength and power training. A review. J Sports Med Phys Fitness 29: 9-26, 1989.
18. Häkkinen, K and Häkkinen, A. Neuromuscular adaptations during intensive strength training in middle-aged and elderly males and females. Electromyogr Clin Neurophysiol 35: 137-147, 1995.
19. Häkkinen, K, Kallinen, M, Izquierdo, M, Jokelainen, K, Lassila, H, Malkia, E, Kraemer, WJ, Newton, RU, and Alen, M. Changes in agonist-antagonist EMG, muscle CSA, and force during strength training in middle-aged and older people. J Appl Physiol 84: 1341-1349, 1998.
20. Harts, CC, Helmhout, PH, De Bie, RA, and Staal, JB. A high-intensity lumbar extensor strengthening program is little better than a low-intensity program or a waiting list control group for chronic low back pain: A randomised clinical trial. Aust J Physiother 54: 23-31, 2008.
21. Hayden, JA, Van Tulder, MW, Malmivaara, AV, and Koes, BW. Meta-analysis: Exercise therapy for nonspecific low back pain. Ann Intern Med 142: 765-775, 2005.
22. Heymans, MW, Van Tulder, MW, Esmail, R, Bombardier, C, and Koes, BW. Back schools for non-specific low-back pain. Cochrane Database Syst Rev CD000261, 2004.
23. Hoffman, JR, Ratamess, NA, Klatt, M, Faigenbaum, AD, Ross, RE, Tranchina, NM, McCurley, RC, Kang, J, and Kraemer, WJ. Comparison between different off-season resistance training programs in Division III American college football players. J Strength Cond Res 23: 11-19, 2009.
24. Iwai, K, Nakazato, K, Irie, K, Fujimoto, H, and Nakajima, H. Trunk muscle strength and disability level of low back pain in collegiate wrestlers. Med Sci Sports Exerc 36: 1296-1300, 2004.
25. Jensen, MP, Miller, L, and Fisher, LD. Assessment of pain during medical procedures: A comparison of three scales. Clin J Pain 14: 343-349, 1998.
26. Kell, R and Asmundson, GJ. A comparison of two forms of periodized exercise rehabilitation programs in the management of chronic non-specific low back pain. J Strength Cond Res 23: 513-524, 2008.
27. Khalil, TM, Asfour, SS, Martinez, LM, Waly, SM, Rosomoff, RS, and Rosomoff, HL. Stretching in the rehabilitation of low-back pain patients. Spine 17: 311-317, 1992.
28. Koldas Dogan, S, Sonel Tur, B, Kurtais, Y, and Atay, MB. Comparison of three different approaches in the treatment of chronic low back pain. Clin Rheumatol 27: 873-881, 2008.
29. Kraemer, WJ. A series of studies-The physiological basis for strength training in American football: Fact over philosophy. J Strength Cond Res 11: 131-142, 1997.
30. Kraemer, WJ, Häkkinen, K, Triplett-McBride, NT, Fry, AC, Koziris, LP, Ratamess, NA, Bauer, JE, Volek, JS, McConnell, T, Newton, RU, Gordon, SE, Cummings, D, Hauth, J, Pullo, F, Lynch, JM, Fleck, SJ, Mazzetti, SA, and Knuttgen, HG. Physiological changes with periodized resistance training in women tennis players. Med Sci Sports Exerc 35: 157-168, 2003.
31. Kraemer, WJ, Ratamess, N, Fry, AC, Triplett-McBride, T, Koziris, LP, Bauer, JA, Lynch, JM, and Fleck, SJ. Influence of resistance training volume and periodization on physiological and performance adaptations in collegiate women tennis players. Am J Sports Med 28: 626-633, 2000.
32. Lang, E, Liebig, K, Kastner, S, Neundorfer, B, and Heuschmann, P. Multidisciplinary rehabilitation versus usual care for chronic low back pain in the community: Effects on quality of life. Spine J 3: 270-276, 2003.
33. Lemmer, JT, Martel, GF, Hurlbut, DE, and Hurley, BF. Age and sex differentially affect regional changes in one repetition maximum strength. J Strength Cond Res 21: 731-737, 2007.
34. Mannion, AF, Muntener, M, Taimela, S, and Dvorak, J. A randomized clinical trial of three active therapies for chronic low back pain. Spine 24: 2435-2448, 1999.
35. Mannion, AF, Taimela, S, Muntener, M, and Dvorak, J. Active therapy for chronic low back pain part 1. Effects on back muscle activation, fatigability, and strength. Spine 26: 897-908, 2001.
36. Matveyev, LP. Periodization of Sports Training. Moscow: Fiscultura i Sport, 1966.
37. Maul, I, Läubli, T, Oliveri, M, and Krueger, H. Long-term effects of supervised physical training in secondary prevention of low back pain. Eur Spine J 14: 599-611, 2005.
38. Nadler, SF, Malanga, GA, Bartoli, LA, Feinberg, JH, Prybicien, M, and Deprince, M. Hip muscle imbalance and low back pain in athletes: Influence of core strengthening. Med Sci Sports Exerc 34: 9-16, 2002.
39. Niemisto, L, Lahtinen-Suopanki, T, Rissanen, P, Lindgren, KA, Sarna, S, and Hurri, H. A randomized trial of combined manipulation, stabilizing exercises, and physician consultation compared to physician consultation alone for chronic low back pain. Spine 28: 2185-2191, 2003.
40. Prestes, J, De Lima, C, Frollini, AB, Donatto, FF, and Conte, M. Comparison of linear and reverse linear periodization effects on maximal strength and body composition. J Strength Cond Res 23: 266-274, 2009.
41. Quinney, HA, Dewart, R, Game, A, Snydmiller, G, Warburton, D, and Bell, G. A 26 year physiological description of a National Hockey League team. Appl Physiol Nutr Metab 33: 753-760, 2008.
42. Renkawitz, T, Boluki, D, and Grifka, J. The association of low back pain, neuromuscular imbalance, and trunk extension strength in athletes. Spine J 6: 673-683, 2006.
43. Rhea, MR and Alderman, BL. A meta-analysis of periodized versus nonperiodized strength and power training programs. Res Q Exerc Sport 75: 413-422, 2004.
44. Rhea, MR, Ball, SD, Phillips, WT, and Burkett, LN. A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength. J Strength Cond Res 16: 250-255, 2002.
45. Ritchie, JD, Miller, CK, and Smiciklas-Wright, H. Tanita foot-to-foot bioelectrical impedance analysis system validated in older adults. J Am Diet Assoc 105: 1617-1619, 2005.
46. Smeets, RJ, Wittink, H, Hidding, A, and Knottnerus, JA. Do patients with chronic low back pain have a lower level of aerobic fitness than healthy controls? Are pain, disability, fear of injury, working status, or level of leisure time activity associated with the difference in aerobic fitness level? Spine 31: 90-97; discussion 98, 2006.
47. Spennewyn, KC. Strength outcomes in fixed versus free-form resistance equipment. J Strength Cond Res 22: 75-81, 2008.
48. Vincent, WJ. Statistics in Kinesiology. 2nd ed. Champaign, Illinois: Human Kinetics, 1999.
49. Vlaeyen, JW and Linton, SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: A state of the art. Pain 85: 317-332, 2000.
50. Ware, J and Sherbourne, C.The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 30: 473-483, 1992.
51. Weir, JP. Quantifying test-retest reliability using the intraclass correlation coefficient and the SEM. J Strength Cond Res 19: 231-240, 2005.
Keywords:
chronic pain; disability; ice hockey; rehabilitation; progressive overload
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