Health Education Research Advance Access originally published online on August 23, 2006
Health Education Research 2007 22(3):305-317; doi:10.1093/her/cyl067
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A home-based, transtheoretical change model designed strength training intervention to increase exercise to prevent osteoporosis in Iranian women aged 40–65 years: a randomized controlled trial
1 Department of Health Education, School of Medical Sciences, Tarbiat Modares University, Al-Ahmad and Chamran Cross, PO Box 14115-111, Tehran, Iran
2 Health Services Research Centre, Faculty of Health and Life Sciences, Coventry University, Priory Street, CV1 5FB, Coventry, UK
3 Department of Physical Therapy, Tarbiat Modares University, Al-Ahmad and Chamran Cross, PO Box 14115-111, Tehran, Iran
4 Interprofessional Research Centre in Health, Faculty of Health and Life Sciences, Coventry University, Priory Street, CV1 5FB, Coventry, UK
5 Department of Biostatistics, Tarbiat Modares University, Al-Ahmad and Chamran Cross, PO Box 14115-111, Tehran, Iran
* Correspondence to: K. K. Shirazi. E-mail: karimzadehshirazi{at}yahoo.com
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
Physical activity (PA) helps to prevent osteoporosis, but older women are often sedentary. This study used a pre–post randomized controlled design to evaluate a 12-week exercise education intervention program based on the stages of change (SoC) and processes of change from the transtheoretical change model (TTM) to improve adherence with strength and balance training recommendations at levels sufficient to prevent osteoporosis in Iranian women aged 40–65 years. The home-based exercise prescription consisted of strength and balance training that was progressive, individually tailored and included a walking program. Individuals in the training group (n = 61) had a positive, significant progression in psychological SoC (P < 0.001), whereas no progression in stages occurred in the control group (n = 55). After the intervention, the training group demonstrated significant improvements in PA, lower body muscle strength, static and dynamic balance, with no significant changes in the control group. These results support the applicability of the TTM for a PA intervention and indicate that this training program is very effective in improving balance and lower body strength in older women.
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
Osteoporosis is a chronic debilitating disease, characterized by age-related decreases in bone mass [1]. It has been estimated that
200 million women are affected worldwide [2]. The results of the national program for prevention, diagnosis and treatment of osteoporosis in Iran have revealed that >70% of women and 50% of men over the age of 50 years suffer from osteoporosis or osteopenia, which makes this a very important public health priority for Iran's health system [2]. Epidemiological and experimental exercise studies, in turn, indicate that physical activity (PA) and regular bone loading exercise are crucial in improving and maintaining bone mass and strength, and so preventing osteoporotic and fall-related fractures [3, 4]. The benefits of strength training include increased muscle and bone mass, muscle strength, flexibility and dynamic balance [5]. A cross-sectional study showed that no citizens >55 years old in a province of Iran were achieving the minimum requirements of PA (defined as exercise at least three times per week for 20 min at moderate intensity or higher) [6]. Another study in Iran showed that only 6% of female nurses reported regular exercise at the required levels [7]. Also there are some cultural barriers to Iranian women exercising in public places. There are few woman-only fitness centers, which few can afford, and there is an expectation that women will prioritize household responsibilities. There is a need for research to establish effective ways of helping older women to develop healthy and sustainable exercise habits.
The use of a behavioral theory, such as transtheoretical change model (TTM) to develop effective interventions in the exercise domain has been reported extensively [8–11]. The TTM has been described as an integrative and comprehensive model of behavior change that has drawn from all major theories of psychotherapy [12]. The stages of change (SoC) dimension of TTM is the temporal dimension identifying the ‘when’ part of the change equation. The processes of change (PoC) dimension of TTM involves understanding ‘how’ individuals change their behavior. This includes cognitive, affective, evaluative and behavioral strategies that an individual may use to modify the problem behavior [13, 14]. Table I defines each of the 10 PoC as it applies to PA (below). Research has demonstrated that an integration of the stages and PoC can provide a useful guide for PA interventions [15].
|
The education and exercise prescription intervention was tailored to SoC using PoC strategies appropriate to each stage, with outcome variables of PA, muscle strength and balance, with the aim of reducing risk of osteoporosis. Given the high rates of osteoporosis and also low exercise rates of women in Iran, the purpose of this study was to design and evaluate a 12-week exercise education intervention program based on TTM to improve adherence with strength training and balance retraining recommendations suitable for the cultural context of older Iranian women. This is the first randomized controlled trial to include and evaluate the TTM components of training in a study of exercise promotion to prevent osteoporosis.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
Design and participants
The study was a randomized controlled trial with two conditions, and pre–post intervention measurements of stage of change, PA level, muscle strength and balance.
This paper reports findings from a larger study, in which the required sample size to achieve 80% power at 5% level of significance on the main variable of interest (dietary calcium) between the training and control groups was calculated to be 52 [5, 16]. To allow for attrition and non-suitability of participants, 200 women were invited to take part. This part of the study found a mean (SD) difference of 7.6 (3.4) in static balance (centimeter) between the training and control groups in change from pre- to post-training, and a retrospective sample size calculation achieved power in excess of 95%. Similar power was achieved when considering the difference in changes in muscle strength (kilogram) between the two groups (mean = 2.4, SD = 1.7).
There are 39 urban District Health Centers located in four homogenous socio-economic areas in Shiraz, Iran. In the first stage of randomization, we randomly selected one area consisting of nine centers. Then, two centers were randomly selected and assigned to a training center and control center. In each center, 100 women who might be expected to meet our study inclusion criteria (age 40–65 years old, education of at least fifth grade) were randomly selected to take part. Their contact details were obtained from the records in the centers. Twenty-eight women in the training center and 37 women in the control center refused for various reasons. Twenty-two women in the training group and 30 in the control group who refused to participate in the research refused because they would not permit home visits. Four women in the control group were excluded as they were engaged in osteoporosis preventive behaviors under the advice of their physicians. The remaining nine (six in the training group and three in the control group) refused because they stated that they were too busy with their household responsibilities to participate in our program. In attempting to control for factors that differed between respondents and non-respondents, we acknowledge that we were unable to assess and subsequently control for osteoporosis preventive behaviors and other variables among those who did not respond.
The remaining 72 women in the training center and 63 women in the control center were screened by the physicians for exclusion criteria: cardiovascular, neurological, systemic illness and osteoporotic fractures. We excluded women with pregnancy, a previous diagnosis of osteoporosis, or severe musculoskeletal disability, which would limit exercise. After initial screening, 61 women in the training center and 55 women in the control group were available for Time 1 assessment and all women also were available for Time 2 and 3 assessments without any drop-out (Fig. 1). The centers were far enough from each other to minimize the likelihood of contact between women (contamination). The assessments were performed by researchers who were blinded to the group types of participants. At the end of the education program, all women agreed not to engage in any strengthening or aerobic exercise in addition to the experimental protocol. The women in the control group were placed on a waiting list for the intervention. The Tarbiat Modares University ethics board approved the study and all participants provided written informed consent.
|
Measures
Stages of exercise change
The Stages of Exercise Change Questionnaire (SECQ) was adapted from Marcus et al. [17]. The stages and their basic definition, in terms of exercise behavior were pre-contemplation (not participating in exercise and not thinking about starting in the next 6 months), contemplation (not participating in exercise but thinking about starting within 6 months), preparation (doing some exercise but below a criterion level), action (started participating in exercise above a criterion level in the last 6 months) and maintenance (participating above a criterion level for >6 months). The criterion level was defined as exercising three times per week for
20 min at a moderate intensity or higher [18]. Five statements were presented (one based on each stage of change) and the participant was asked to select the statement that best described her current level of exercise. The Kappa index of reliability for the SECQ, taken over a 2-week period was 0.78 (n = 20) [17]. Concurrent validity for the SECQ was evidenced by its significant association with the 7-day PA recall questionnaire [19, 20].
Physical activity
PA was assessed by an adapted short version (continuous score) of the International Physical Activity Questionnaire (IPAQ) [21] which provided information on the time spent on walking (as exercise), vigorous and moderate-intensity activity. IPAQ was developed by an international consensus group, which met in Geneva 1998, as a self-reported measure of PA suitable for population surveillance of adults 15–69 years. It has been used also as an evaluation tool in some intervention studies. Validity and reliability of the instrument have been reported [22]. Given the focus of the research on exercise behavior change, data are presented as mean minutes (not mean Met-minutes).
Muscle strength
Muscle strength was measured as the force generated during a maximum voluntary contraction. The one-repetition maximum (1RM) test is typically used to measure strength in the research setting. One advantage is that this test is more specific to the type of training participants would be most likely to perform to enhance strength levels [23].
The 1RM was used as the measure of muscle strength of the knee extensor. A 1RM signifies the maximum resistance a person can move in one repetition of an exercise. To estimate a person's 1RM, we determined an nRM (n 
10). We used a regression equation attributed to Brzycki [24].
 |
The formula permits assessment of muscular strength in a safe, efficient manner without requiring participants to attempt maximum lifts.
Ankle cuff weights were used to provide resistance during the test. They were available in a range of styles and weights. They could be added to or replaced with heavier weights when the person could achieve >10 repetitions.
Static balance
Functional reach is the maximal distance an individual can lean forward with his/her arm flexed to 90° while maintaining a fixed base of support in the standing position. This was assessed to determine static balance as it is predictive of falls and functional status, it is related to the range of motion of axial spinal rotation, and it is sensitive to change with exercise [25, 26].
Dynamic balance
Dynamic balance is the ability to anticipate changes and coordinate muscle activity to perturbation of stability [23]. Dynamic balance was evaluated by performing the star-excursion balance tests (SEBTs). This is a functional test that incorporates a single-leg stance on one leg with maximum reach of the opposite leg. The reliability of the SEBTs has been investigated in two previous studies [27, 28]. Due to space and cost requirements associated with instrumental devices, they were neither affordable nor practicable for the clinical setting. Thus, a simple, reliable and valid method of lower limb functional performance was needed [29]. The star-excursion test offers a simple, reliable, low cost alternative to more sophisticated instrumented methods that are currently available [28].
Procedure
Two health professionals who were speakers of the language of Iran and graduated at British Universities translated the questionnaires into Persian. The questionnaires were backward translated into English by a native English speaker living in Iran.
The PA questionnaire was completed before and after the intervention, and the SoC of exercise was assessed at baseline, and at weeks 2 and 12 of the program for all participants. Muscle strength, dynamic and static balance tests were performed before starting the exercise program with the final testing after the intervention, and each was performed by one of the specially trained physical therapists on all assessments. Prior to testing, all procedures were demonstrated to participants. Each woman was tested by the same tester on all visits.
Intervention
Education program
The education program had both a common part and a stage-specific part. The common instructional strategies of the program included the following:
- (i) ‘Gain attention’ to the program through raising consciousness about osteoporosis risks, severity and consequences of a sedentary lifestyle.
- (ii) Enhance ‘relevancy’ and perceived susceptibility using peer-case presentation.
- (iii) Set progressive ‘small objectives’ tailored to each participant.
- (iv) Make instructions ‘easy’ to understand and to do.
- (v) ‘Enhance self-efficacy’ for desired behaviors.
- (vi) ‘Encourage’ the participants to continue the program by providing appropriate feedback and verbal incentives.
- (vii) Develop ‘social support’ by family interviews.
- (ii) Enhance ‘relevancy’ and perceived susceptibility using peer-case presentation.
The education materials of the common part of the training intervention aimed to increase the participants' knowledge of osteoporosis, the risk factors and effects and preventive behaviors with a focus on the benefits of exercise and muscle strength training. The sessions aimed to increase awareness of personal susceptibility to osteoporosis and the threats of fractures. The importance of performing regular PA with the aim of prevention of osteoporosis and falls was explained during these sessions.
Instructions were tailored to participants' stage of change. The PoC has been applied in PA intervention previously [14], where it was found that experiential processes are used more in the early SoC, while use of behavioral processes tends to peak in the action stages [30, 31]. So, for the pre-action stages (pre-contemplation, contemplation and preparation), the education was focused on increasing emotional readiness to change and start exercise. In the action stages (action and maintenance), the intervention concentrated on the skills needed to implement and maintain appropriate daily exercise. Every 2 weeks, the participants' stages in the trial group were determined and each woman received reminder cards and a pamphlet based on her most recent stage. She was asked to display the cards in a suitable place at home. Table I summarizes the educational objectives and integration of the stages and processes used in reminder cards and pamphlets [31].
The exercise education program began with a home-visit session for each participant in preparation and action stages and for others, as soon as they progressed to these stages. The main objective of this phase was improvement of muscle strength and balance. To start the program, we showed the participants the exercise booklet that explained the exercise instructions during the session as each individual exercise was prescribed. The instructor took the person through the exercise ensuring she was safe and confident with each one and could understand the illustrations and instructions. All women had the instructor's contact telephone number and were asked to report any changes in physical symptoms or exacerbations of existing medical conditions such as arthritic pain, where women were advised to stop exercising and to contact the team's physician. We involved family members in recruitment and in carrying out the program.
Exercise program
The exercise program was progressive, individually tailored and included a walking program as a weight-bearing exercise.
We used elastic bands that were inexpensive, transportable and took up minimal space [32]. The muscles exercised were the hip extensors, hip flexor, hip abductors, hip adductors and knee extensors, because they are important for transferring and fall prevention. Each participant received an elastic band with the same thickness and varying wideness specified according to her own 1RM at the baseline measurement, as the widths of 3, 5 and 7 cm were used, for 1RMs of <5, 5–7 and >7 kg, respectively.
Prior to the strengthening exercises with the elastic band, participants did a 5-min stretch warm-up, and a similar cool down was performed after the exercise session. Strengthening exercise included five exercises with elastic bands that were performed progressively (see Table II).
|
Each repetition lasted 5–6 s, with a 3-s rest between repetitions, 60 s of rest between sets and 2 min rest between exercises. Right and left legs were trained at the same time and each session lasted 30–45 min and was separated by 1 day of rest. After strengthening exercises, the participants performed one of the three balance training exercises (knee bends and forward lean), with progression from Level 1 (the first or easiest) to Level 4 (the most difficult), as shown in Table II. The instructor observed the participant during the holding version of each balance exercise before prescribing the exercise without holding support. The prescription for walking was at least 30 min day–1 that was broken up into two or three minimum 10-min sessions.
Statistical analyses
Data analyses were completed using the statistical software program SPSS version 12. Two-tailed tests were performed and a 5% level of significance was set.
Baseline demographic data are described using means and standard deviations (SDs). Comparisons of study variable means at baseline between the training and control groups were performed using the two-tailed, independent Student's t-test for all but PA measures. PA was combined (walking, moderate and vigorous exercise) to produce an overall time in minutes spent exercising. PA measures were compared between training and control groups using the Mann–Whitney (M-W) test, as these data were not normally distributed. PA stages of readiness to change PA behavior were merged into two categories: pre-action (pre-contemplation, contemplation and preparation) and action (action and maintenance). Chi-square tests were used to compare these categories between the two groups at pre- and post-training. Progression through the time points for the two groups was compared using the Friedman test. Univariate analysis of covariance was performed on the change from pre- to post-training values of appropriate outcome variables, with the pre-training values used as covariate. Change in PA data between groups was compared using M-W test.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
Program adherence and compliance
The prescribed moderate-intensity exercise criterion of at least 20 min session–1 for 3 days week–1 over the 10 weeks of exercise program was attained by 47.5% of the participants in the training program, compared with 20.0% of the control group (exact
2 = 9.71, P = 0.003).
Pre-training data
Baseline demographic characteristics of the population are summarized in Table III. There were no significant baseline differences in age, body mass index and education level, between the training and control groups. At baseline, there were similar proportions of participants in each of the five stages (see Table IV) and chi-square analysis indicated no significant difference between pre-action and action categories at baseline. Thirty-two percent in the intervention and 38% of the control groups reported spending any time on PA at baseline. Chi-square analysis indicated no significant difference in performing exercise, or not, between the two groups.
|
|
The t-tests revealed no baseline differences between groups in static balance and other directions of dynamic balance, but 1RM (P < 0.001) and the right-posterior direction of dynamic balance were significantly higher in the control group than training group (see Table V).
|
Post-training data
Stage of change
Progression in SoC was used as one of the criteria of intervention success. A highly significant difference at the end of the training program (
2 = 45.8, P < 0.001) was found between the training and control groups. Figure 2 illustrates these differences.
|
Individuals in the training group had a positive, significant progression through the program (Friedman
2 = 76.17, P < 0.001), whereas limited progression occurred in the control group (Friedman 2 = 4.52, P = 0.104). After the education program (2 weeks), the training group had a larger percentage of participants in the preparation and action stages than the control group and a larger percentage of control group participants in pre-contemplation and contemplation. At 12 weeks, the training group had a smaller proportion of participants in pre-action stages than the control group. Percentages of participants in each stage are summarized in Table IV.
Other outcome variables
Figure 3 illustrates the overall time in minutes spent exercising pre- and post-training. The outliers (small circles and asterisks) show that a few members in both groups were spending more time exercising than the majority, although the training group increased the time spent exercising overall (M-W Z = –4.13, P < 0.001). Results of univariate analyses of variance on the changes from pre- to post-training, with baseline values and the two variables identified as significantly different at baseline used as covariates, indicated very highly statistically significant differences (all P < 0.001) between the training group and the control group for all outcome variables (see Table V). It was noted that the assumption of homogeneity of variance was not met for these tests, possibly due to the very small changes in measures within the control group. Equivalent non-parametric analyses (M-W test) revealed the same, very clear, significant results.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
The study examined the effectiveness of a TTM-based intervention designed to promote PA, and reported the effect of a home-based, tailored progressive and strength training exercise program to improve muscle strength and balance.
In this study, we achieved 100% cooperation (in both groups) without any payment. In addition to the general instructional strategies of the program which were well-received, this high retention rate may have been influenced by the program being free of charge, and novel to all women participating in the health program, along with the short period of follow-up and the frequent home visits during the program and data collection stages.
Education and stage of change
Based on the results of the staging algorithm, at the baseline, there were very large percentages of participants (intervention 88.5%, control 94.6%) in the pre-action stages. The intervention group showed a progression in stage compared with the control group. The increased number of participants in the preparation and action stages at the end-point of the common education program part of the experimental training program (2 weeks) may be attributed to the educational strategies used. The stage of change construct is based on the premise that education can promote an individual's progression through stages [33]. According to the PoC, providing information to individuals in pre-contemplation is an effective strategy for helping them move into contemplation. Other intervention studies have shown a positive relationship between knowledge and stages [33–35]. Knowledge programs such as a lecture on the topic of osteoporosis have helped people in contemplation and preparation to change their attitudes or to prompt them to move into action [36]. At the third follow-up point (12 weeks), the high number of participants in the action stage may be attributed to the high levels of adherence to the exercise prescription. Also, it could be related to their former progression in stages after the common part of intervention. DiClemente and colleagues found that helping people progress through just one stage can double their chances of successful behavioral changes in the near future [14].
At the baseline, both training and control groups demonstrated low levels of PA; however, after 12 weeks of the intervention training, group performance significantly improved. Although it cannot be ruled out that self-assessment measures of exercise are subject to reporting biases [37, 38], in this study objective measures were also used to provide reliability checks on the impact of the intervention. Similar to other research findings [19, 20, 39, 40], in the present study, stage of change as a self-reported instrument has been shown to correspond accurately with more objective measures of PA, e.g. IPAQ, muscle strength, dynamic and static balance.
Exercise prescription and PA
A moderate home-based exercise program was chosen for the present study as the moderate exercise prescription could be easily followed by a healthy individual over a lifetime and it is frequently recommended by health professionals [41–43]. Also, the effectiveness and efficiency of home exercise programs have been reported previously [44–47].
For some women, exercising at home is the most realistic and desirable option. Individuals can exercise whenever they desire, without the constraint of a class schedule, and they can adapt their program as necessary to match their goals [32]. This could be more important in a developing country due to the high costs of any group exercise program. The inclusion of two group-education sessions at the start of the program may have increased social support among participants for health behavior change.
Another aspect of our prescription was the use of elastic bands in strength training exercise. Elastic bands were readily available and inexpensive, and this equipment was accepted by participants very well. Although more improvement in muscle strength and physical function by using some expensive equipment (machines) and free weighs (dumb-bells and ankle weights) has been reported than elastic bands [32], the current research indicates that strength training using elastic bands can improve muscle strength by an average of 58%, dynamic balance 8.53% and static balance 66.18%. These improvements can be clinically significant. Tinetti et al. [48] investigated the effectiveness of a multi-factorial intervention program on a number of risk factors for falls and concluded that a change in balance score of 1, where possible scores ranged from 0 to 12, was associated with an 11% reduction in fall rates [49]. Winters and Snow [50] in a study involving pre-menopausal women found that impact plus lower limb resistance exercise significantly increased knee extensor and hip abductor strength by 17 and 27%, respectively. They also found that dynamic postural stability was improved by 24%, and that lead to significant increases in trochantric and femoral neck Bone Mineral Density of 2.5 and 1.5%, respectively.
Although several trials have demonstrated the effectiveness of a home-based strength and balance program, they showed various results depending upon study group chosen, exercise intervention and measurements instruments. In a study by Jette et al. [51], disabled men and women aged 60 years old or more were trained in a home-based intervention using elastic bands of varying thickness. After the intervention, strength had improved 6–12% in the lower limbs, and tandem gate improved 20% in the exercise group. Campbell et al. [44, 45], in an individualized program of lower limb strength and balance exercises, showed a significant reduction in the rate of falls per annum among women aged 80 years and older, compared with a control group. Robertson et al. [46, 47], in a home-based strength and balance training program reported that after the intervention the number of falls was reduced by 30%. These studies illustrate that a home-based approach offers a feasible method for implementing strength and balance training programs in older adults. Gardner et al. [52] found similar results to this study in New Zealand for the combined effects of walking plus resistance training in increasing both lower extremity strength and balance. Walking and other activities should be part of comprehensive strength and balance training programs for older adults in community health promotion programs. These results suggest that an exercise program that incorporates the use of elastic bands can produce improved muscle strength, dynamic and static balance in middle-aged and older women. Therefore, it is suggested that this type of training be incorporated into the exercise routines of apparently healthy adults and used as part of specific falls and osteoporosis prevention programs.
Although the present study reported meaningful findings, there are limitations that need to be taken into consideration when interpreting the results and planning future research. Perhaps the biggest limitation is that there is no post-intervention follow-up due to the time restriction for performing the study, so it is not possible to assess the maintenance or generalization of effects into sustained healthy exercise beyond the exercises prescribed in the program.
To summarize, a combination of three factors, (i) giving the importance of exercise in terms of disease prevention such as osteoporosis, (ii) tailoring the messages and exercise prescription to the stages and PoC and (iii) prescribing a home-based, inexpensive, individualized and progressive strength training program, is feasible and effective method to encourage sedentary middle-aged and older women to do exercise.
|
Conflict of interest statement |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
None declared.
|
Acknowledgements |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
Grateful appreciation is extended to Elaheh Rahimi for her assistance in this project.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConflict of interest statementAcknowledgementsReferences |
|---|
1. Ethgen O, Tellier V, Sedrine WB, et al. Health related quality of life and cost of ambulatory care in osteoporosis: how may such outcome measures by valuable information to health decision makers and payers? Bone (2003) 32:718–24.[Medline]
2. Larijani B. Osteoporosis in Iran. Proceedings of the First International Seminar on Prevention, Diagnosis Treatment of Osteoporosis in Tehran, Iran. Available at: http://www.osteofound.org. Accessed: 23 November 2004.
3. Kannus P, Parkkari J, Sievanen H, et al. Epidemiology of hip fractures. Bone (1996) 18:57S–63.[Medline]
4. Carter ND, Kannus P, Khan KM. Exercise in the prevention of falls in older people. Sports Med (2001) 31:427–38.[CrossRef][Web of Science][Medline]
5. Nelson ME, Fiatarone MA, Morganti CM. Effects of high-intensity strength training on multiple risk factors for osteoporosis fractures: a randomized controlled trial. J Am Med Assoc (1994) 272:1909–14.
6. Ahmadi A, Shirazi KK, Fararooie M. Prevalence of cardiovascular risk factors in elderly people of Yasuj. J Yasuj Med Sci Univ (2000) 20:11–7.
7. Yekta Z, Pourali R, Kafili M, et al. An osteoporosis KAP study in Ourumiyeh hospital nurses. Paper presented at the first national congress on health education in Yazd, Iran. Toloo-e-Behdasht (2003) 2:177.
8. Prochaska JO, Marcus BH. The transtheoretical model: applications to exercise. In: Advances in Exercise Adherence—Dishman RK, ed. (1994) Champaign, IL: Human Kinetics Books. 161–80.
9. Gorely T, Bruce DA. 6-month investigation of exercise adoption from the contemplation stage of the transtheoretical model. Psychol Sport Exerc (2000) 1:89–101.[CrossRef]
10. Plotlikoff RC, Hotz SB, Birkett NJ, et al. Exercise and transtheoretical model: a longitudinal test of a population sample. Prev Med (2001) 33:441–52.[CrossRef][Web of Science][Medline]
11. Jordan PG, Nigg CR, Norman GJ, et al. Does the transtheoretical model need an attitude adjustment? Integrating attitude with decisional balance as predictor of stage of change for exercise. Psychol Sport Exerc (2002) 3:65–83.[CrossRef]
12. Prochaska JO, Norcross JC. Comparative Conclusion: Toward a Transtheoretical Therapy. Systems of Psychotherapy: A Transtheoretical Analysis (1999) Pacific Grove, CA: Brooks/Cole. 487–528.
13. Prochaska JO, Velicer WF, DiClemente CC, et al. Measuring processes of change: application to the cessation of smoking. J Consult Clin Psychol (1988) 56:520–8.[CrossRef][Web of Science][Medline]
14. Woods C, Mutrie N, Scott M. Physical activity intervention: transtheoretical model-based intervention designed to help sedentary young adults become active. Health Educ Res (2002) 17:451–60.
15. Marcus BH, Bock BC, Pinto BM, et al. Efficacy of an individualized, motivationally-tailored physical activity intervention. Ann Behav Med (1998) 20:174–80.[Web of Science][Medline]
16. Marascuilo LA, Serlin RC. Statistical Methods for the Social and Behavioral Sciences (1988) NY: Freeman & Company.
17. Marcus BH, Rakowski W, Rossi JS. Assessing motivational readiness and decision making for exercise. Health Psychol (1992) 11:257–61.[CrossRef][Web of Science][Medline]
18. Nigg CR, Courneya KS. Transtheoretical model: examining adolescent exercise behavior. J Adolesc Health (1998) 22:214–24.[CrossRef][Web of Science][Medline]
19. Marcus BH, Simkin LR. The stages of exercise behavior. J Sports Med Phys Fitness (1993) 33:83–8.[Web of Science][Medline]
20. Wallace LM, Sh Niknami, Shirazi KK. Validation of a stage of change algorithm for exercise behaviour in women of 35-70 years. In: Research on the Transtheoretical Model: Where Are We Now, Where Are We Going?—Keller S, Velicer WF, eds. (2004) Berlin: PaBst. 129–34.
21. IPAQ. Guidelines for Data Processing and Analysis of the International Physical Activity Questionnaire (IPAQ)—Short Form. Available at: http://www.ipaq.ki.se. Accessed: 23 July 2004.
22. Craig CL, Marshall AL, Sjostrom M, et al. International physical activity questionnaire: 12-country reliability and validity. Med Sci Sports Exerc (2003) 35:1381–95.
23. Rogers ME, Rogers NL, Takeshima N, et al. Methods to evaluate and improve the physical parameters associated with fall risk in older adults. Prev Med (2003) 36:255–64.[CrossRef][Web of Science][Medline]
24. Mayhew JL, Prinster JL, Ware JS, et al. Muscular endurance repetitions to predict bench press strength in men of different training levels. J Sports Med Phys Fitness (1995) 35:108–13.[Web of Science][Medline]
25. Duncan PW, Weiner DK, Chandler J, et al. Functional reach: a new clinical measure of balance. J Gerontol (1990) 45:M192–7.[Abstract]
26. Duncan PW, Studenski SA, Chanler JM, et al. Functional reach: predictive validity in a sample of elderly male veterans. J Gerontol (1992) 47:M93–8.[Abstract]
27. Kinzey SJ, Armstrong CW. The reliability of the star-excursion test in assessing dynamic balance. J Orthop Sports Phys Ther (1998) 27:356–60.[Web of Science][Medline]
28. Hertel J, Miler SJ, Denegar CR. Intratester and intertester reliability during the star excursion balance test. J Sport Rehabil (2000) 9:104–16.[Web of Science]
29. Cohen H, Blatchly CA, Gombash LL. A study of the clinical test of sensory interaction and balance. Phys Ther (1993) 73:346–54.
30. Prochaska JO, DiClemente CC. Stages and process of self-change of smoking: toward an integrative model of change. J Consult Clin Psychol (1983) 51:390–5.[CrossRef][Web of Science][Medline]
31. Prochaska JM, Paiva AL, Padula JA, et al. Assessing emotional readiness for adoption using the transtheoretical model. Child Youth Serv Rev (2005) 27:135–52.[CrossRef][Web of Science]
32. Seguin R, Nelson ME. The benefits of strength training for older adults. Am J Prev Med (2003) 25(Suppl. 2):141–9.[CrossRef][Web of Science][Medline]
33. Molaison EF, Yadrick MK. Stage of change and fluid intake in dialysis patients. Patient Educ Couns (2003) 49:5–12.[CrossRef][Web of Science][Medline]
34. Auld GW, Nitzke SA, McNulty J, et al. A stage-of-change classification system based on actions and beliefs regarding dietary fat and fiber. Am J Health Promot (1998) 12:192–201.[Web of Science][Medline]
35. Campbell MK, Reynolds KD, Havas S, et al. Stages of change for increasing fruit and vegetable consumption among adults and young adults participating in the national 5-a-day for better health community studies. Health Educ Behav (1999) 26:513–34.
36. Lach HW, Everard KM, Highstein G, et al. Application of the transtheoretical model to health education for older adults. Health Promot Pract (2004) 5:88–93.
37. Brug J, Hospers H, Kok G. Differences in psychological factors and fat consumption between stages of change for fat reduction. Psychol Health (1997) 12:719–27.[Web of Science]
38. Lechner L, Brug J, De Vries H, et al. Stage of change for fruit, vegetable and fat intake: consequences of misconception. Health Educ Res (1998) 13:1–13.
39. Cardinal BJ. Construct validity of stages of change for exercise behavior. Am J Health Promot (1997) 12:68–74.[Web of Science][Medline]
40. Lowther M, Mutrie N, Loughlan C, et al. Development of a Scottish physical activity questionnaire: a tool for use in physical activity interventions. Br J Sports Med (1999) 33:244–9.[Abstract]
41. Marcus R. Understanding and preventing osteoporosis. Hosp Pract (1989) 24:189–218.
42. Sinaki M. Exercise and osteoporosis. Arch Phys Med Rehabil (1989) 70:220–9.[Web of Science][Medline]
43. Nelson ME, Fisher EC, Dilmanian FA, et al. A 1-Y walking program and increased dietary calcium in postmenopausal women: effects on bone. Am J Clin Nutr (1991) 53:1304–11.
44. Campbell AJ, Robertson MC, Gardner MM, et al. Randomized controlled trial of a general practice program of home based exercised to prevent falls in elderly women. Br Med J (1997) 315:1065–69.
45. Campbell AJ, Robertson MC, Gardner MM, et al. Fall prevention over two years: a randomized controlled trial in women 80 years and older. Age Ageing (1999) 28:513–8.
46. Robertson MC, Devlin N, Gardner MM, et al. Effectiveness and economic evaluation of a nurse delivered home exercise program to prevent falls 1: randomized controlled trial. Br Med J (2001) 322:697–701.
47. Robertson MC, Gardner MN, Devlin N, et al. Effectiveness and economic evaluation of a nurse delivered home exercise program to prevent falls 2: controlled trial in multiple centers. Br Med J (2001) 322:701–4.
48. Tintti ME, McAvay G, Claus E. Dose multiple risk factor reduction explain the reduction in fall rate in the Yale FICSIT trial? Am J Epidemiol (1999) 144:389–99.
49. Gardner MM, Robertson MC, Campbell AJ. Exercise in preventing falls and fall related injuries in older people: a review of randomised controlled trials. Br J Sports Med (2000) 34:7–17.
50. Winters KM, Snow CM. Detraining reverses positive effects of exercise on the musculoskeletal system in pre menopausal women. J Bone Miner Res (2000) 15:2495–503.[CrossRef][Web of Science][Medline]
51. Jette AM, Lachman M, Giorgetti MM, et al. Exercise—it's never too late: the strong for life program. Am J Public Health (1999) 89:66–72.
52. Gardner MM, Phty M, Robertson MC, et al. Application of a falls prevention program for older people to primary health care practice. Prev Med (2002) 34:546–53.[CrossRef][Web of Science][Medline]
Received on July 9, 2005; accepted on June 15, 2006
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C. E. Garber, J. E. Allsworth, B. H. Marcus, J. Hesser, and K. L. Lapane Correlates of the Stages of Change for Physical Activity in a Population Survey Am J Public Health, May 1, 2008; 98(5): 897 - 904. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||