Assessment of the effects of aquatic therapy on global symptomatology in patients with fibromyalgia syndrome: a randomized controlled trial
Keywords
Article abstract
OBJECTIVES:
To evaluate the effects of a 16-week exercise therapy in a chest-high pool of warm water through applicable tests in the clinical practice on the global symptomatology of women with fibromyalgia (FM) and to determine exercise adherence levels.
DESIGN:
A randomized controlled trial.
SETTING:
Testing and training were completed at the university.
PARTICIPANTS:
Middle-aged women with FM (n=60) and healthy women (n=25).
INTERVENTION:
A 16-week aquatic training program, including strength training, aerobic training, and relaxation exercises.
MAIN OUTCOME MEASURES:
Tender point count (syringe calibrated), health status (Fibromyalgia Impact Questionnaire); sleep quality (Pittsburgh Sleep Quality Index); physical (endurance strength to low loads tests), psychologic (State Anxiety Inventory), and cognitive function (Paced Auditory Serial Addition Task); and adherence 12 months after the completion of the study.
RESULTS:
For all the measurements, the patients showed significant deficiencies compared with the healthy subjects. Efficacy analysis (n=29) and intent-to-treat analysis (n=34) of the exercise therapy was effective in decreasing the tender point count and improving sleep quality, cognitive function, and physical function. Anxiety remained unchanged during the follow-up. The exercise group had a significant improvement of health status, not associated exclusively with the exercise intervention. There were no changes in the control group. Twenty-three patients in the exercise group were exercising regularly 12 months after completing the program.
CONCLUSIONS:
An exercise therapy 3 times a week for 16 weeks in a warm pool could improve most of the symptoms of FM and cause a high adherence to exercise in unfit women with heightened FM symptomatology. The therapeutic intervention's effects can be assessed through applicable tests in the clinical practice.
Article content
FIBROMYALGIA IS A CHRONIC musculoskeletal pain syndrome that is associated with a wide variety of symptoms, such as sleep disturbances,1 fatigue,2 low muscular performance,3 cognitive disturbances,4 anxiety, and depressed moods.5
Several controlled studies have shown that different kinds of exercise programs may modulate pain,6, 7 health-related quality of life,8 sleep quality,6, 7 cognitive function,9 and anxiety10 in patients with FM. However, no study has yet addressed the effects on sleep quality through a specific test or the effects of exercise alone on global FM symptomatology; a growing body of evidence has suggested that exercise is beneficial for patients with FM.11
One of the main effects of the therapeutic programs is the incorporation of physical activity in the patients' daily lives. Various studies12 have shown that detraining affects the main cardiovascular, metabolic, and muscular parameters, even among elite athletes, within 4 weeks.
This state of disadaptation has also been shown in FM patients.8 However, exercise adherence after several months of postintervention has been assessed in very few exercise programs in FM patients. With regards to the aquatic programs performed in water only, very few determined adherence after the intervening period.13
One of the major objectives of increasing scientific knowledge is its applicability to daily clinical practice. Researchers have assessed the symptomatology in FM patients and the effects of therapeutic interventions by using technology and/or tests of difficult accessibility for most health care professionals. For example, several studies have assessed pain threshold, sleep quality, cognitive dysfunction, strength, and cardiorespiratory fitness through dolorimetry,14 polysomnography,15, 16 single photon-emission computed tomography or auditory P300 event-related brain potentials,4 isokinetic dynamometers,8 and the 6MWT.10, 17 At the same time, other studies continued to use less valid and precise methodologies, such as digital palpation in the assessment of pain,17, 18 VASs to assess pain17, 19, 20 or sleep quality,6, 20, 21 and the chair-stand test22 to assess the strength.7, 10, 23
Therefore, the purpose of the present study was to evaluate the effects of a 16-week exercise therapy in a chest-high pool of warm water through applicable tests in the clinical practice on the global symptomatology of women with FM and to determine adherence to an exercise regimen. In addition, this study determined the differences in global symptomatology between FM patients and healthy subjects.
Methods
Design and Participants
An invitation to participate in the study was sent to women (n=250) ages 18 to 60 years old from a local FM association in Spain. Sixty-eight potentially eligible subjects responded and sought more information. Those 68 eligible patients gave written consent after the study protocol was explained to them. Patients' personal medical records were examined by a physician, and a diagnosis of FM was confirmed according to the ACR classification criteria.2 To determine the differences among patients with FM and healthy controls, a group of 25 healthy women volunteers matched according to age, weight, body mass index, educational, and physical activity level were recruited. All healthy subjects gave written consent. The study flow of participants is presented in figure 1.
Fig 1
The flow of participants throughout the trial.
The exclusion criteria included the presence of subjects with a history of morbid obesity, known cardiopulmonary diseases, endocrine or allergic disturbances uncontrolled, severe trauma, frequent migraines, inflammatory rheumatic diseases, and severe psychiatric illness. In addition, subjects with other diseases that prevent physical loading and those who were pregnant were also omitted. Finally, those FM women who attended another type of physical or psychologic therapy were excluded to avoid possible interactions with the present trial. Patients with a history of regular physical activity more strenuous than slow-paced walking a maximum of 2 times a week over 4 months before study entry were excluded from the final analysis according to the criteria of Schachter et al.18 The Spanish version24 of the revised Physical Activity Readiness Questionnaire25 was also administered to identify persons at risk for adverse events while exercising. On the whole, 8 patients were excluded from the study because they were attending a psychologic therapy program (n=2), exercised regularly (n=2), or had a history of severe trauma (n=1), arrhythmia (n=1), inflammatory rheumatic disease (n=1), or psychiatric illness (n=1).
According to the aforementioned criteria, a final sample of 60 FM women was randomly assigned to either an exercise group or a control group according to a computer-generated randomization list. Different numbers of patients were allocated to each group to ensure that both groups completed the intervening period with a comparable quantity of patients, despite the elevated exercise therapy attrition rate26, 27 (randomization ratio, 1.4:1). The results of the randomization were unknown until the participant accepted or declined to participate in the project. Six patients in the exercise group and 1 in the control group were not included in the analysis for diverse reasons. Finally, 29 women from the exercise group and 24 women from the control group fully completed the study and were included in the efficacy analysis (see fig 1). The control group was instructed not to change their habits regarding physical activities during the period. The exercise group followed an aquatic training program 3 times a week for 16 weeks. All patients were allowed to continue their usual daily activities as earlier, to use their regular medication, and to visit medical professionals if needed.
The evaluation of the outcome measures was performed immediately after the training period at 16 weeks. The initial measurements before the training period started were designated as baseline values. All measurements were taken by examiners blinded to group assignment. The Committee on Biomedical Ethics of the Aragon Government approved this study.
Exercise Therapy
The exercise group trained in a chest-high warm pool (32° C) 3 times a week for 16 weeks. Each session included 10 minutes of warming up with slow walks and mobility exercises, 10 to 20 minutes of strength exercises developed at a slow pace using water and aquatic materials as a means of resistance including a stepped progression during the program (table 1), 20 to 30 minutes of aerobic exercises developed progressively at intensity sufficient to achieve 50% to 80% of the age predicted maximum heart rate equation (220 – age) (see table 1), and 10 minutes of cooling down with low-intensity and relaxation exercises. Heart rate was monitored with a pulse meter.a The intervention program met the minimum training standards of the American College of Sports Medicine.28
| Period (wk) | Strength Training Progression | Aerobic Training Progression | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Repetitions | Weekly Routines | Sets | Exercises | Duration (min) | Weekly Frequency | Intensity (%) HRmax | Duration (min) | Weekly Frequency | |
| 1–2 | 10–15 | A | 1 | 8 | 8–10 | 3 | 50–60 | 20–25 | 3 |
| 3–4 | 10–15 | A | 1–2 | 8–10 | 10–15 | 3 | 55–65 | 20–25 | 3 |
| 5–8 | 10–12 | B1, B2 | 1–2 | 8–10 | 10–15 | 3 | 60–70 | 20–25 | 3 |
| 9–12 | 10–12 | B1, B2 | 2–3 | 8–10 | 15–20 | 3 | 65–75 | 25–30 | 3 |
| 13–16 | 8–10 | C1, C2, C3 | 2–3 | 8–10 | 15–20 | 3 | 70–80 | 25–30 | 3 |
Abbreviations: A, all major muscular groups; B1, trapezius, latissimus-dorsi, biceps brachii, abductors, adductors and torso muscles (ie, abdominals, oblique and lumbar); B2, pectoralis, triceps brachii, deltoids, gluteus, quadriceps, knee flexors (ie, biceps femoris, semimembranosus, and semitendinosus) and gastrocnemius muscles; C1, trapezius, latissimus-dorsi, biceps brachii and torso muscles; C2, gluteus, quadriceps, knee flexors, gastrocnemius, abductors and adductors muscles; C3, pectoralis, triceps brachii, deltoids and torso muscles; HRmax, age-predicted maximal heart rate equation (220–age).
Pain Measures
Pressure pain thresholds in all tender points, according to ACR-1990 classification criteria,2 were measured by using a syringe calibrated like a pressure dolorimeter.9 The syringe was calibrated to obtain the equivalency of cm3 in kg of pressure to determine the amount of tender points positive to the exploration according to the guidelines the ACR recommends for FM diagnosis. The equivalencies of cm3 in kg of pressure were 10cm3=2.5kg, 11cm3=3kg, 12cm3=3.5kg, 13cm3=4kg, and 14cm3=5kg. A tender point is considered positive to the exploration when the patient manifests pain with a pressure of 13cm3 or less.
For each patient, the number of examined points that were found to be positive during the exploration or sore to a pressure of 4kg or less (13cm3) was recorded.
Health Status Measures
The influence of FM on functional impairment and health status was assessed with the validated Spanish version29 of the FIQ. The original version of the FIQ was designed by Burckhardt et al30 to evaluate the severity of FM on daily activities. Previous researches31, 32 have shown adequate reliability and validity of this measure. The questionnaire is scored from 0 to 100, in which a higher score indicates a greater impact of the syndrome on the person.
Psychologic Measures
The level of current anxiety was measured with the Spanish version33 of the 20-item self-administered SAI.34 Higher scores on the SAI indicate a greater state of anxiety (range, 20–80) and have been widely used to measure anxiety in psychiatric and medical samples and have proven to be sensitive to exercise-induced changes in anxiety.35
Sleep Quality Measures
The influence of FM on sleep quality was assessed with the Spanish version36 of the PSQI,37 an instrument previously administered in FM patients38, 39 with established reliability and validity. This method consists of 19 self-rating questions combined into 7 components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medications, and daytime dysfunction. These component scores are then summed to yield a global PSQI score, which has a range of 0 to 21, with higher scores indicating worse sleep quality.
Cognitive Function Measures
All participants were asked to complete the PASAT. This standardized neuropsychologic test measures sustained and divided attention, auditory information processing speed, and stimulus competition filtering skill.40 In this study, the PASAT was administered only at the slowest presentation rate of 2.4 seconds. The score is the number of correct responses over 60 trials.
Physical Function Measures
The endurance strength of each subject's upper- and lower-extremities was evaluated by recording the number of repetitions from 2 properly designed tests: the endurance strength to low loads tests.
The lower-extremities endurance strength to low loads test was administered by using a folding chair without arms, with a seat height of 43.2cm. The chair, with rubber tips on the legs, was placed against a wall to prevent it from moving during the test. The test began with the participant seated in the middle of the chair, back straight, feet approximately shoulder width apart and placed on the floor at an angle slightly back from the knees, with 1 foot slightly in front of the other to help maintain balance when standing. Arms were extended longitudinally to the trunk, and each hand held a dumbbell of 2.5kg. At the signal of the metronome, the participant rose to a full stand (body erect and straight), and at the next signal of the metronome, the participant returned back to the initial seated position maintaining the arms extended. The pace of the metronome was 90°/s. The score was the total number of stands executed correctly until the participant could not keep up with the pace. The test-retest reliability was satisfactory (ICC2.1=.94, P<.001).
The upper-extremities endurance strength to low loads test was administered by using the same chair as the one used for the lower extremities. The test began with the participant seated in the middle of the chair, leaning back completely, with the arm being tested extended longitudinally to the trunk and holding a dumbbell of 2.5kg in weight. At the signal of the metronome, the participant curled the weight through a full range of motion. At the next signal of the metronome, the participant returned back to the initial position keeping the back straight. The pace of the metronome was 120°/s. The score was the total number of stands executed correctly until the participant could not keep up with the pace. This test was repeated for the other arm. The reliability was satisfactory (ICC2.1=.88, P<.001 for the right arm; ICC2.1=.91, P<.001 for the left arm).
Adherence to Training
For each patient, we recorded the number of training sessions attended during the study. After a 16-week intervention, the researchers did not have contact with the patients. Twelve months from the completion of the study, we contacted patients by telephone to determine whether they continued on an exercise program.
Statistical Analysis
We analyzed data on an efficacy (29 exercise and 24 control patients) and ITT (34 exercise and 24 control patients) basis. Subjects who attended the exercise sessions and participated in testing at all points (before and after sessions) were included in the ITT analysis. To be included in the efficacy analysis, participants had to attend 75% or more of the exercise sessions. We evaluated the normality of the variables through the Kolmogorov-Smirnov and Shapiro-Wilk tests, with Lilliefors significance. The results are expressed as the mean ± SD or 95% confidence interval. We compared the differences in baseline variables among the healthy, exercise, and control groups through the analysis of variance of a particular factor. We applied the Kruskall-Wallis and chi-square tests in samples with no homogeneous distribution and in qualitative variables, respectively. We used the Student t test and the Mann-Whitney U test to compare baseline measures between the healthy subjects and the FM patients. The statistical analysis of the data focused on the interactions between group (exercise/control) and time (times 1-2, with the first assessment occurring before the therapeutic intervention and time 2 occurring immediately after the 16-week intervention). This analysis also controlled for selected covariates. When data were not normally distributed, we applied the Wilcoxon analysis to observe differences for repeated measures. For these variables, we used the Mann-Whitney U test to observe if the changes in the variables were different between the experimental and control groups. We applied the Spearman analysis to examine the relation between the changes in the variables and selected baseline measures. We used the ICCs model 2.1 to establish test-retest reliability for the physical function measures. The α level was set at .05.
Results
As far as program compliance is concerned, only 2 subjects had to be eliminated because of exercise recidivism rate. These women (6%) dropped out during the program because of transportation problems and employment commitments. The remaining 33 patients attended a mean of 42 (range, 30–48) exercise sessions out of a possible 48. This represents an 88% attendance rate. All subjects attended at least half (n=24) of the exercise sessions, with the majority (86%) attending at least 75% (n=6). Three women (9%) from the exercise group were excluded from the efficacy analysis for not attending at least 75% of the exercise sessions. Another woman (3%) was excluded from the efficacy analysis because she did not attend assessments. During the 12 months after completing the exercise program, 23 patients in the exercise group (79% efficacy analysis vs 68% ITT analysis) participated regularly in exercise programs: 20 patients in pool-based programs and 3 patients in other types of programs (see fig 1).
Efficacy and ITT analyses showed similar baseline characteristics for the exercise, control, and healthy groups (table 2). The healthy group showed significantly better efficacy and ITT analyses results. Specifically, the health status; sleep quality; and psychologic, physical, and cognitive function measures were improved as compared with the FM group in all parameters assessed. FM patients were severely affected (ie, SAI, PSQI, endurance strength to low loads tests scores >2 SD below and above healthy group, respectively) (table 3).
| Group | Efficacy Analysis | ITT Analysis | ||||||
|---|---|---|---|---|---|---|---|---|
| Exercise (n=29) | Control (n=24) | Healthy (n=25) | P | Exercise (n=34) | Control (n=24) | Healthy (n=25) | P | |
| Ethnicity (%) | ||||||||
| White | 100 | 100 | 100 | NA | 100 | 100 | 100 | NA |
| Age (y) | 50±7 | 46±8 | 47±10 | 0.175 | 50±7 | 46±8 | 47±10 | 0.182 |
| Body mass index (kg/m2) | 27±5 | 27±4 | 26±4 | 0.985 | 27±4 | 27±4 | 26±4 | 0.965 |
| Duration of symptoms (y) | 14±10 | 14±9 | ND | 0.922 | 14±9 | 14±9 | ND | 0.883 |
| Tender point count (1–18) | 15.1±3.9 | 16.1±2.9 | ND | 0.355 | 15.2±3.6 | 16.1±2.9 | ND | 0.411 |
| Occupation (%) | 0.901 | 0.841 | ||||||
| Domestic labor | 52 | 67 | 60 | 50 | 67 | 60 | ||
| Operatives | 21 | 17 | 12 | 21 | 17 | 12 | ||
| Office or store worker | 17 | 13 | 20 | 17 | 13 | 20 | ||
| Manager | 10 | 4 | 8 | 12 | 4 | 8 | ||
| Highest education (%) | 0.916 | 0.901 | ||||||
| Elementary school | 59 | 63 | 60 | 56 | 63 | 60 | ||
| High school | 31 | 29 | 24 | 32 | 29 | 24 | ||
| College/university | 10 | 8 | 16 | 12 | 8 | 16 | ||
NOTE. Values are the mean ± SD unless otherwise indicated; values listed as NA are NA because this variable is constant.
Abbreviations: NA, not applicable; ND, no data.
| Efficacy Analysis | ITT Analysis | |||||
|---|---|---|---|---|---|---|
| FM Group (n=53) | Healthy Group (n=25) | P | FM Group (n=58) | Healthy Group (n=25) | P | |
| FIQ (0–100) | 66.1±15.0 | 10.6±9.2 | 0.000 | 66.3±14.4 | 10.6±9.2 | 0.000 |
| Endurance-strength tests (reps) | ||||||
| Left arm | 14.8±21.9 | 55.0±41.9 | 0.000 | 14.7±20.9 | 55.0±41.9 | 0.000 |
| Right arm | 16.0±21.7 | 59.6±36.8 | 0.000 | 15.6±20.8 | 59.6±36.8 | 0.000 |
| Lower extremities | 22.3±26.7 | 82.0±46.3 | 0.000 | 22.4±25.5 | 82.0±46.3 | 0.000 |
| SAI (20–80) | 50.1±11.5 | 33.2±5.3 | 0.000 | 50.3±11.1 | 33.2±5.3 | 0.000 |
| PSQI (0–21) | 11.9±5.0 | 4.2±2.9 | 0.000 | 12.2±4.9 | 4.2±2.9 | 0.000 |
| PASAT test, 2.4s (0–60) | 26.8±14.2 | 40.5±12.6 | 0.000 | 26.7±13.6 | 40.5±12.6 | 0.000 |
NOTE. Values are the mean ± SD unless otherwise noted.
Efficacy and ITT analyses showed significant improvements of exercise therapy on the clinical variables (table 4). The number of tender points decreased significantly in the exercise group (29% efficacy analysis vs 26% ITT analysis). Exercise therapy also significantly improved the score on the PSQI (16% efficacy analysis vs 13% ITT analysis) and on the pace auditory serial addition task (26% efficacy analysis vs 23% ITT analysis). The repetitions performed in the endurance strength test increased significantly with therapeutic intervention: left arm (314% efficacy analysis vs 271% ITT analysis), right arm (265% efficacy analysis vs 231% ITT analysis), and lower extremities (116% efficacy analysis vs 102% ITT analysis). The score in the SAI remained unchanged during the follow-up. The exercise group showed a statistically significant improvement in the FIQ (8%, P=.020 efficacy analysis vs 7%, P=.005 ITT analysis), which was not associated exclusively with the exercise intervention (P=.122 efficacy analysis vs P=.116 ITT analysis). In the control group, none of the clinical variables showed significant changes with respect to the initial assessment. The effects of exercise therapy were independent of the baseline characteristics of the patients.
| Efficacy Analysis (Exercise [n=29] vs Control [n=24]) | Intent-To-Treat Analysis (Exercise [n=34] vs Control [n=24]) | |||||
|---|---|---|---|---|---|---|
| Baseline | Change From Baseline to 16 Weeks | Baseline | Change From Baseline to 16 Weeks | |||
| Mean ± SD | Mean (95% CI) | P⁎ | Mean ± SD | Mean (95% CI) | P⁎ | |
| Tender point count (1–18) | ||||||
| Exercise | 15.1±3.9 | −4.4 (−5.8 to −3.0) | 0.000 | 15.2±3.6 | −3.9 (−5.1 to −2.6) | 0.001 |
| Control | 16.1±2.9 | −0.3 (−1.7 to 1.1) | 16.1±2.9 | −0.3 (−1.7 to 1.1) | ||
| FIQ (0–100) | ||||||
| Exercise | 68.2±13.4 | −5.1 (−8.9 to −1.3) | 0.122 | 68.1±12.4 | −4.8 (−8.1 to −1.6) | 0.116 |
| Control | 63.6±16.7 | −0.9 (−4.8 to 2.9) | 63.6±16.7 | −0.9 (−4.8 to 2.9) | ||
| Endurance strength tests (reps) | ||||||
| Left arm | ||||||
| Exercise | 10.9±10.7 | 34.2 (25.2 to 43.4) | 0.000 | 11.3±9.9 | 30.6 (22.3 to 38.9) | 0.000 |
| Control | 19.5±30.1 | 4.4 (−2.2 to 11.0) | 19.5±30.1 | 4.4 (−2.2 to 11.0) | ||
| Right arm | ||||||
| Exercise | 12.1±12.2 | 32.1 (21.8 to 42.3) | 0.000 | 12.2±11.3 | 28.2 (18.9 to 37.5) | 0.001 |
| Control | 20.6±29.1 | 8.2 (−0.1 to 16.5) | 20.6±29.1 | 8.2 (−0.1 to 16.5) | ||
| Lower extremities | ||||||
| Exercise | 23.2±23.7 | 26.9 (14.3 to 39.6) | 0.001 | 23.3±21.8 | 23.8 (12.7 to 34.8) | 0.001 |
| Control | 21.2±30.4 | 9.8 (−1.7 to 21.3) | 21.2±30.4 | 9.8 (−1.7 to 21.3) | ||
| SAI (20–80) | ||||||
| Exercise | 52.2±11.7 | −0.3 (−4.0 to 3.3) | 0.979 | 52.2±10.8 | −0.3 (−3.4 to 2.8) | 0.961 |
| Control | 47.6±11.0 | −0.4 (−4.6 to 3.8) | 47.6±11.0 | −0.4 (−4.6 to 3.8) | ||
| PSQI (0–21) | ||||||
| Exercise | 13.3±4.7 | −2.0 (−3.0 to −1.1) | 0.000 | 13.4±4.4 | −1.7 (−2.6 to −0.9) | 0.000 |
| Control | 10.4±5.0 | 0.5 (−0.4 to 1.3) | 10.4±5.0 | 0.5 (−0.4 to 1.3) | ||
| PASAT Test, 2.4s (0–60) | ||||||
| Exercise | 25.7±15.5 | 6.7 (3.1 to 10.3) | 0.004 | 25.7±14.3 | 5.9 (2.7 to 9.0) | 0.006 |
| Control | 28.2±12.7 | 1.2 (−2.1 to 4.4) | 28.2±12.7 | 1.2 (−2.1 to 4.4) | ||
NOTE. Values are mean ± SD unless otherwise noted.
Abbreviation: CI, confidence interval.
Discussion
This study shows that exercise therapy 3 times a week over 16 weeks in a chest-high pool of warm water improves the majority of the symptoms of FM, including tender point count, sleep quality, cognitive function, and physical fitness. These improvements were shown in both the efficacy and ITT analysis, but the improvements were larger and more significant in the efficacy analysis. Health status, measured by means of the FIQ, also improved significantly in the exercise group. However, this change was not caused by the exercise therapy only. Probably the variation of the season between the pre- and postmeasures (January–May) partially explains the differences found in the health status. Some authors suggest that season influences the functional impairment and health status of the FM patients, improving significantly in the warm months.23, 41, 42
We did not find differences in anxiety levels after treatment. This was probably because of the duration of program intervention and because we did not include educational treatment. The majority of studies related to FM and exercise that achieved significant psychologic improvements developed programs greater than 20 weeks17, 20 and/or included educational programs.10, 43, 44, 45
We emphasize the elevated adherence to the exercise program in the exercise group. This strong adherence has been observed in few studies.13, 46 It has been justified with the scarce dropout rate (6%, n=2), high attendance rate (88%) during the intervention period, and the high percentage of patients (79% efficacy analysis vs 68% ITT analysis, n=23) who continued the exercise program on their own cost and without our encouragement 12 months after the completion of the study. This indicates that our program has broken the vicious cycle of insufficient exercise and deteriorating fitness. An important finding is that most of the patients incorporated the exercise program into their daily lives and, consequently, minimized the detraining effects. These results suggest that the aquatic program is an adequate type of exercise to cause elevated exercise adherence. However, we are not aware of a study that determines the influence of different programs of physical activity on adherence.
This is the first study that assesses the effects of an exercise program on sleep quality by means of the PSQI. Other studies have assessed sleep by means of brief and nonspecific tests or simple VASs.6, 7, 21, 43, 47, 48 We consider that the PSQI is a more consistent and specific instrument, is broadly used, and is validated to establish and examine the quality and sleep disorders.36, 49, 50 Furthermore, it is considered to be a useful and sensitive instrument for characterizing and quantifying sleep disturbances in FM patients.38
Another important finding is the sensitivity of the PASAT to determine changes in cognitive function. This test is used frequently in the scientific literature and has increased reliability and internal consistence.51 However, it has currently been used only in very few studies to appraise the cognitive function in FM patients,9, 52, 53 and only our research group has used it to determine exercise-induced changes.9 In addition, the PASAT has larger applicability in the clinical daily practice than the single photon-emission computed tomography or auditory P300 event-related brain potentials.4
The introduction of a new method to appraise pain in FM patients is scientifically valuable.9 Up until now, pain has been largely assessed through the use of a dolorimeter, digital palpation, or self-reported VASs. Digital palpation does not permit quantifying the pain threshold, and, therefore, it is not sensitive enough to the therapeutic changes. VASs do not permit quantifying the tender point count and have been shown to be insufficiently sensitive to the therapeutic changes.11 In fact, we have observed that most studies that have assessed pain through quantitative instruments (myalgic scoring, readings from a calibrated syringe, dolorimeter, or pressure algometer) have obtained significant changes in pain after therapeutic exercise programs.6, 9, 43, 47, 54 In contrast, exercise programs that used a dichotomous variable (present/absent) generally did not observe changes after the intervention period.17, 23
Even though physical dysfunction is a major limitation among FM patients, its assessment in daily clinical practice is limited by the availability of scientific instruments and amenities, notably isokinetic dynamometers,8, 17, 47 fitness machines,26 ergospirometers,13, 55 and a 6MWT.10, 17 One of the few tests measuring physical fitness that is applicable in the daily clinical practice and used with FM patients7, 10, 23 is the chair-stand test.22 This test aims to have the patient complete as many full stands as possible within 30 seconds. The temporal limitation obligates the patient to perform the exercise at the maximum velocity possible. Therefore, the functional and metabolic perspective cannot adequately assess the healthy physical fitness in a clinical population. In this study, we have modified the chair-stand test by controlling the pace of movement through means of a metronome to induce heightened aerobic metabolism. Similarly, we have modified the arm curl test56 in the assessment of the upper extremities because it presented the same temporary limitation as the chair-stand test. Both tests designed in our study have shown good reliability and sensitivity to therapeutic effects. These tests can be used in daily clinical practice to appraise fitness in FM patients.
We have observed an important increase in repetitions of lower and upper extremities endurance strength tests after completing the program. This increase in the strength could be symptomatic of a decrease of pain, even though the exercise program could have ameliorated central regulation of pain. This decrease of pain could be caused by the lower percentage of strength needed to perform the same physical activity (ie, climbing stairs). Furthermore, the values for the control and exercise group are similar. For this reason, we reject a neuromuscular and metabolic deficiency in FM patients. Given the short duration of the program, we consider that the increase in repetitions may not be exclusively attributed to neuromuscular and metabolic adaptations. The other factors that should be considered are the increase of the pain threshold and a decrease in fear of the physical effort induced by the therapeutic intervention.
Study Limitations
Because the results of our study could have been affected by the small sample size, we recommend determining the validity and reliability of the 2 tests we proposed with a more extensive sample.
Conclusions
The results of the efficacy and ITT analysis of this study show that an exercise therapy program with moderate intensity performed 3 times a week for 16 weeks in a chest-high pool of warm water (32°C) has no apparent negative effects and improves pain, sleep quality, and physical and cognitive function, causing a great adherence to exercise in previously unfit women with heightened and long FM symptomatology. Further research could determine what programs of physical activity induce a larger adherence in FM patients.
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