Case-control study of lifetime total physical activity and prostate cancer risk

A population-based case-control study of physical activity and prostate cancer risk was conducted in Alberta, Canada, between 1997 and 2000. A total of 988 incident, histologically confirmed cases of stage T2 or greater prostate cancer were frequency matched to 1,063 population controls. The Lifetime Total Physical Activity Questionnaire was used to measure occupational, household, and recreational activity levels from childhood until diagnosis. Multivariable logistic regression analyses were conducted. No association for total lifetime physical activity and prostate cancer risk was found (odds ratio (OR) for > or =203 vs. <115 metabolic equivalent-hours/week/year=0.87, 95% confidence interval (CI): 0.65, 1.17). By type of activity, the risks were decreased for occupational (OR=0.90, 95% CI: 0.66, 1.22) and recreational (OR=0.80, 95% CI: 0.61, 1.05) activity but were increased for household (OR=1.36, 95% CI: 1.05, 1.76) activity when comparing the highest and lowest quartiles. For activity performed at different age periods throughout life, activity done during the first 18 years of life (OR=0.78, 95% CI: 0.59, 1.04) decreased risk. When activity was examined by intensity of activity (i.e., low, <3; moderate, 3-6; and vigorous, >6 metabolic equivalents), vigorous activity decreased prostate cancer risk (OR=0.70, 95% CI: 0.54, 0.92). This study provides inconsistent evidence for the association between physical activity and prostate cancer risk.

A randomized trial of exercise and quality of life in colorectal cancer survivors

We conducted a randomized controlled trial to determine the effects of a home-based exercise intervention on change in quality of life (QOL) in recently resected colorectal cancer survivors, most of whom were receiving adjuvant therapy. Participants were randomly assigned in a 2:1 ratio to either an exercise (n = 69) or control (n = 33) group. The exercise group was asked to perform moderate intensity exercise 3-5 times per week for 20-30 min each time. The primary outcome was change in QOL as measured by the Functional Assessment of Cancer Therapy-Colorectal (FACT-C) scale. Adherence in the exercise group was good (75.8%) but contamination in the control group was problematic (51.6%). Intention-to-treat analysis revealed no significant differences between groups for change in the FACT-C (mean difference, -1.3; 95% CI, -7.8 to 5.1; P = 0.679). In an 'on-treatment' ancillary analysis, we compared participants who decreased versus increased their cardiovascular fitness over the course of the intervention. This analysis revealed significant differences in favour of the increased fitness group for the FACT-C (mean difference, 6.5; 95% CI, 0.4-12.6; P = 0.038). These data suggest that increased cardiovascular fitness is associated with improvements in QOL in colorectal cancer survivors but better controlled trials are needed.

Predicting exercise stage transitions over two consecutive 6-month periods: a test of the theory of planned behaviour in a population-based sample

OBJECTIVES

To predict exercise stage transitions over two consecutive 6-month periods using the theory of planned behaviour (TPB). It was hypothesized that different social cognitive constructs would predict different stage transitions.

DESIGN

Prospective and longitudinal in order to predict multiple stage transitions over time. Assessments were made at baseline, 6 months and 1 year.

METHOD

Participants were a randomly selected population-based sample of 683 adults who completed two telephone interviews (baseline and 6 months) that assessed exercise stage, intention, perceived behavioural control, attitude, subjective norm, and social support, and a mailed survey (1 year) that assessed exercise stage.

RESULTS

Progression from pre-contemplation was predicted by intention, attitude and subjective norm; progression/regression from contemplation was predicted by intention, perceived behavioural control, attitude, and social support; progression/regression from preparation was predicted by intention and attitude; and regression from action/maintenance was predicted by intention, attitude and social support.

CONCLUSIONS

Different social cognitive constructs predicted different stage transitions, which indicates that exercise behaviour change may be represented by a series of stage transitions. Moreover, the TPB may be a useful model for highlighting the key social cognitive constructs that are important for exercise stage transitions.

Framework PEACE: an organizational model for examining physical exercise across the cancer experience

The primary purpose of this article is to provide a framework for organizing research on physical exercise and cancer control. A secondary purpose is to use this framework to provide an overview of the extant literature and to offer directions forr future research. The proposed framework, entitled Physical Exercise Across the Cancer Experience (PEACE), divides the cancer experience into 6 time periods: 2 prediagnosis (i.e., prescreening and screening/diagnosis) and 4 postdiagnosis (i.e., pretreatment, treatment, posttreatment, and resumption). Based on these time periods, 8 general cancer control outcomes are highlighted. Two cancer control outcomes occur prediagnosis (i.e., prevention and detection), and 6 occur postdiagnosis (i.e., buffering, coping, rehabilitation, health promotion, palliation, and survival). An overview of the physical exercise literature indicates that only I time period (i.e., prescreening) and cancer control outcome (i.e., prevention) has received significant research attention. Some time periods (i.e., treatment and resumption) and cancer control outcomes (i.e., coping and health promotion) have received modest research attention, whereas other time periods (i.e., screening/diagnosis, pretreatment, and posttreatment) and cancer control outcomes (i.e., detection, buffering, rehabilitation, palliation, and survival) have received only minimal attention. It is hoped that Framework PEACE will stimulate a more comprehensive and in-depth inquiry into the role of physical exercise in cancer control.

Validating motivational readiness for exercise behavior with adolescents

The stages of motivational readiness as conceptualized by the Transtheoretical Model have been widely used among adult samples to assess readiness for adopting exercise behavior. To date, little research has been conducted using a staging framework with adolescent samples. There is a need for validation of the staging framework prior to a substantial amount of research with this age group. The current article presents two studies assessing stage and reported exercise behavior (Study 1: n = 819; M age = 15.0 years, SD = 1.2; 51% men; Study 2: n = 184; M age = 18.6 years, SD = .5; 45% men). As hypothesized in both studies, reported exercise consistently varied as a function of stage classification; those in earlier stages of readiness reported less exercise than those in later stages. Staging algorithms showed good sensitivity to detect reported exercise; however, specificity was distinctly better with the algorithm that used a specific activity criterion and immediate intention, as opposed to irregular behavior, in defining the preparation stage. Results support the validity of the staging framework for measuring motivational readiness for exercise behavior among North American adolescents.

Exercise and the transtheoretical model: a longitudinal test of a population sample

BACKGROUND

The purpose of this study was to test the ability of the Transtheoretical Model (TTM) to predict exercise stage transition of individuals in a large, untreated-population-based, random sample of Canadian adults (18-65 years of age) over two consecutive time periods.

METHODS

Assessments of TTM's stage of exercise behavior change, self-efficacy, pros, cons, experiential processes, and behavioral processes were made at baseline (time 1), 6 months (time 2), and 1 year (time 3). Six hundred eighty-three men and women, identified through random-digit telephone dialing, completed all measures across the three time points. Within each time period (time 1-2; time 2-3) participants were categorized as having regressed (moved back at least on stage), remained (no stage change), or progressed (moved forward at least one stage). Baseline TTM constructs were analyzed for their ability to predict change transition across the two time periods.

RESULTS

Of 40 possible predictions (20 for each time period) 18 (45%) were supported.

CONCLUSIONS

Overall, the findings demonstrate partial support for the internal validation of TTM in the exercise domain. Implications of the findings are discussed and future directions for researchers, practitioners, and program planners are provided.

Effects of acute exercise on state anxiety in breast cancer survivors

PURPOSE/OBJECTIVES

To examine the effects of an acute bout of exercise on state anxiety in breast cancer survivors.

DESIGN

A two-group (high and low state anxiety) by two-time (pre- and postexercise) mixed factorial design.

SETTING

Exercise physiology lab at the University of Alberta.

SAMPLE

34 stage I or II breast cancer survivors ranging in age from 39-65 (X = 50.50; SD = 6.62).

METHODS

Participants completed the State Anxiety Inventory prior to and five minutes following an acute bout of exercise.

MAIN RESEARCH VARIABLES

State anxiety.

FINDINGS

A main effect resulted for group (p < 0.01) and time showing that state anxiety significantly decreased from pre- to postexercise (p < 0.03). Group by time interaction showed that state anxiety for the low state anxiety group did not change from pre- to postexercise (p > 0.05); however, state anxiety significantly decreased in the high state anxiety group (p < 0.03).

CONCLUSION

Acute exercise may be an effective intervention in reducing state anxiety in breast cancer survivors, especially those with high state anxiety.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses should be aware that in addition to other traditional anxiolytic therapies (e.g., relaxation therapy) commonly prescribed, acute exercise is an effective method for reducing state anxiety in breast cancer survivors.

Influence of physical activity in different age and life periods on the risk of breast cancer

We conducted a population-based case-control study of 1,237 incident breast cancer cases and 1,241 controls in Alberta between 1995 and 1997 to examine the effect of physical activity performed at different ages and life periods on breast cancer risk. In this study, we measured all types of physical activity done throughout life with a questionnaire developed and tested specifically for this study. We found that breast cancer risk was most associated with a risk reduction for activity done later in life, particularly between menopause and the reference year, for which we observed an odds ratio of 0.70 (95% confidence interval = 0.52-0.95). We also stratified the study participants into four categories according to their patterns of physical activity performed before and after menopause. For the women who sustained physical activity throughout life vs those who were never active, we found an odds ratio of 0.58 (95% confidence interval = 0.41-0.83). This study suggests that sustained activity throughout life and particularly activity done later in life may have the most benefit in reducing breast cancer risk.

Relation between intensity of physical activity and breast cancer risk reduction

PURPOSE

To examine the influence of frequency, duration, and intensity of physical activity on risk of breast cancer and to compare breast cancer risks associated with self-reported versus assigned intensity levels of activity.

METHODS

A population-based case-control study of 1233 incident breast cancer cases and 1241 controls was conducted in Alberta between 1995 and 1997. The frequency, duration and intensity of occupational, household, and recreational activities were measured throughout lifetime using the Lifetime Total Physical Activity Questionnaire and cognitive interviewing methods. Unconditional logistic regression analyses were used to estimate odds ratios and a full assessment of confounding and effect modification was undertaken. Odds ratios for self-reported and compendium-based assigned levels of activity were compared for lifetime total activity and by type of activity.

RESULTS

Breast cancer risk reductions were comparable when self-reported and assigned intensity values were used, although the results and trends were more evident with the assigned intensity data. Moderate-intensity occupational and household activities decreased breast cancer risk, whereas recreational activity, at any intensity level, did not contribute to a breast cancer risk reduction.

CONCLUSION

This study found that moderate-intensity activities were the major contributors to the decrease in breast cancer risk found in this study and that risk reductions were more evident when the frequency and duration of activity alone were modeled. Of the three types of activity considered, the greatest risk reductions observed were for occupational and household activities.

Personality and exercise participation across the breast cancer experience

The purpose of this study was to investigate the relationship between personality and exercise participation across the breast cancer experience. Based on the Five-Factor Model and previous exercise research, it was hypothesized that high scores of extraversion (E) and conscientiousness (C), and low scores of neuroticism (N) would discriminate exercise stage during and following cancer treatment as well as changes in exercise stage across the cancer experience (i.e. from prediagnosis through treatment to posttreatment). Participants were 175 non-metastatic breast cancer survivors who completed a mailed questionnaire that assessed demographic and medical information, personality (the NEO-Five Factor Inventory), and exercise stage recalled for three time periods (prediagnosis, during treatment, and posttreatment). Multivariate analysis of variance showed differences in personality based on exercise stage both during cancer treatment and posttreatment and also for exercise pattern across the cancer experience. Univariate F-tests and post hoc analyses identified N, E, and C as the key personality dimensions. N was associated with earlier exercise stages and a maladaptive exercise pattern whereas E and C were associated with more advanced exercise stages and adaptive exercise patterns. It was concluded that personality may be an important determinant of exercise following breast cancer diagnosis.

Exercise adherence in breast cancer survivors training for a dragon boat race competition: a preliminary investigation

Recent research has applied the theory of planned behavior (TPB) to understanding exercise after a cancer diagnosis, but studies are few and have been limited by retrospective designs, self-report measures of exercise and varied results. In the present study, we extended this research by using a prospective design and an objective measure of exercise adherence. Participants were a convenience sample of 24 breast cancer survivors attending a twice weekly, 12-week training program in preparation for a dragon boat race competition. Participants completed a baseline questionnaire that assessed demographic and medical variables, past exercise, and the TPB (i.e. beliefs, subjective norm, attitude, perceived behavioral control and intention). Program attendance was monitored over a 12-week period by the class instructor. Overall, participants attended 66% of the training sessions. Multiple regression analyses indicated that: (a) intention was the sole determinant of program attendance and explained 35% of the variance; (b) the TPB constructs explained 49% of the variance in intention with subjective norm being the most important determinant; and (c) the key underlying beliefs were support from physician, spouse, and friends, and confidence in being able to attend the training class when having limited time, no one to exercise with, fatigue, and other health problems. Based on this preliminary study, it was concluded that the TPB may provide a good framework on which to base interventions designed to promote exercise in breast cancer survivors.

Case-control study of lifetime physical activity and breast cancer risk

A population-based case-control study of 1,233 incident breast cancer cases and 1,237 controls was conducted in Alberta, Canada, in 1995-1997 to examine the effect of lifetime physical activity patterns on breast cancer risk. No associations between physical activity and breast cancer were found for premenopausal women. For postmenopausal women in the highest quartile (> or =161 metabolic equivalent (MET)-hours/week per year) versus the lowest quartile (<104.8 MET-hours/week per year) of lifetime total physical activity, the adjusted odds ratio was 0.70 (95% confidence interval (CI): 0.52, 0.94). When the risks associated with each type of activity were examined for postmenopausal women, household and occupational activity conferred the largest risk reductions (odds ratio (OR) = 0.57, 95% CI: 0.41, 0.79 and OR = 0.59, 95% CI: 0.44, 0.81, respectively, for highest vs. lowest quartiles of activity), while recreational activity was not associated with any risk reductions. For postmenopausal women, the authors found stronger risk reductions for those who were also nonsmokers (OR = 0.64, 95% CI: 0.46, 0.88), non-alcohol-drinkers (OR = 0.39, 95% CI: 0.11, 0.77), or nulliparous (OR = 0.22, 95% CI: 0.07, 0.70) when they compared the highest with the lowest quartile of lifetime total physical activity. This study provides evidence that lifetime total activity reduces risk of postmenopausal breast cancer.

Exercise interventions during cancer treatment: biopsychosocial outcomes

More than 1.2 million Americans are diagnosed with cancer each year, and many receive intensive medical treatments. Currently, exercise is not considered a standard quality-of -life intervention for cancer patients. In this article, 11 studies are reviewed that have examined exercise interventions concurrent with cancer treatment. The key conclusion is that exercise improves a wide range of biopsychosocial outcomes in cancer patients, but much more reserch is needed.

Feeling state responses to acute exercise of high and low intensity

The purpose of the present study was to examine the effects of exercise intensity on feeling states following two acute bouts of exercise (i.e., 50% and 80% of age-predicted maximal heart rate reserve: HRR) in highly fit and unfit females. It was hypothesized that highly fit females would have increased positive well-being and/or reduced psychological distress post-exercise (high intensity) compared to unfit females while both groups would experience similar feeling states following moderate intensity exercise. Twelve highly fit and 12 unfit females completed 3 conditions: attention control and fitness test, and two acute bouts of exercise (30 minutes on a bicycle ergometer) at 50% and 80% age-predicted HRR. Pre- and post-exercise feeling states were measured via the Subjective Experiences Exercise Scale (McAuley & Courneya, 1994). Analyses indicated a time x condition x fitness interaction F(2,21)=6.07, p<.01 (eta2 =.37) for psychological distress. Follow-up univariate analyses revealed no change in the 50% or control conditions, however, psychological distress significantly increased for the unfit participants F(1,11)=4.68,p<.05 (eta2 =.29) while there was no change for the highly fit participants F(1,11)=2.14,p>.05 (eta2 =.16) in the 80% intensity condition. No fitness differences emerged with respect to positive well-being or fatigue. Therefore, the present study's results substantiate the need to consider fitness level in dose-response studies, particularly ones which examine negative feeling states.

Examination of the transtheoretical model and exercise in 3 populations

OBJECTIVE

To examine differences in the processes of change and self-efficacy for exercise across the stages of change in 3 populations to determine its suitability for use in diverse groups.

METHODS

Cross-sectional survey design with population as a between-subjects variable: high school students (n = 168), university undergraduate students (n = 215), and employed adults (n = 63).

RESULTS

ANOVAs revealed main effects of stage (p < .0001) and population (p < .001) in process use and self-efficacy but no population by stage interaction.

CONCLUSIONS

The consistency of patterns of the TTM variables supports its potential for effective intervention in diverse populations.

Coping with cancer: can exercise help?

A comprehensive review of the recent literature reveals that exercise has a positive effect on a broad range of quality-of-life parameters after patients are diagnosed as having cancer. The general exercise prescription is moderate-intensity exercise, 3 to 5 days per week, 20 to 30 minutes per session. Conditions that warrant prescription modification include fatigue periods during treatment, acute or chronic physical impairments that may have resulted from surgery or adjuvant therapy, and the presence of bone cancer. Research suggests that physicians who prescribe exercise improve motivation and adherence in their patients who have cancer.

Physical exercise and quality of life in cancer patients following high dose chemotherapy and autologous bone marrow transplantation

Preliminary evidence indicates that physical exercise may be an effective strategy for the rehabilitation of cancer patients following high dose chemotherapy (HDC) and bone marrow transplantation (BMT), but the focus of this research has been on physical fitness and medical outcomes. In the present study, we employed a prospective design to examine the relationship between physical exercise and various quality of life (QOL) indices in 25 BMT patients. Participants completed weekly self-administered questionnaires upon being admitted to hospital, and monitored the frequency and duration of their exercise during hospitalization. Statistical analyses indicated that exercise during hospitalization was significantly correlated with almost all QOL indices, including physical well-being, psychological well-being, depression, anxiety and days hospitalized. Moreover, only some of the correlations were attenuated after controlling for relevant demographic and medical variables. It was concluded that physical exercise may be related to QOL in BMT patients, but that experimental research is needed before any definitive conclusions can be drawn.

Leisure-time physical activity and psychosocial well-being in adolescents after cancer diagnosis

This preliminary study examined the relationship between leisure time physical activity (LTPA) and psychosocial well-being in 53 adolescents who were previously diagnosed with cancer. Participants completed a mailed, self-administered questionnaire in which they recalled their LTPA (including leisure time exercise and organized sport) at three time points (prediagnosis, treatment, and posttreatment). They also reported their current psychosocial well-being by using measures of depression and self-concept. Examination of the LTPA data revealed four main patterns across the cancer experience that were labeled maintainers (active at all three time points), temporary relapsers (active prediagnosis, inactive during treatment, active posttreatment), permanent relapsers (active prediagnosis, inactive during treatment, inactive posttreatment), and nonparticipants (inactive at all three time points). Multivariate analyses of variance indicated that self-concept differed significantly across the four organized sport patterns. Follow-up univariate analyses revealed significant differences for general self-concept, physical abilities, parental relations, same sex relations, and opposite sex relations with effect sizes ranging from medium-large to large. Post hoc tests generally showed that the maintainers exhibited superior scores on psychosocial well-being compared with the other three patterns. It was concluded that LTPA patterns across the cancer experience may be related to psychosocial well-being in adolescents after cancer diagnosis but that further research is warranted.

Physical exercise and quality of life following cancer diagnosis: a literature review

With almost 8 million Americans alive today who have been through the cancer experience, it is important to develop interventions to maintain quality of life (QOL) following cancer diagnosis. Physical exercise is an intervention that may address the broad range of QOL issues following cancer diagnosis including physical, functional, psychological, emotional, and social well-being. The purpose of the present article was to provide a comprehensive and critical review of the topic and to offer suggestions for future research. The review located 24 empirical studies published between 1980 and 1997. Eighteen of the studies were interventions (i.e. quasi-experimental or experimental) but most of these were preliminary efficacy studies that suffered from the common limitations of such designs. Overall, however, the studies have consistently demonstrated that physical exercise has a positive effect on QOL following cancer diagnosis, including physical and functional well-being (e.g. functional capacity, muscular strength, body composition, nausea, fatigue) and psychological and emotional well-being (e.g. personality functioning, mood states, self-esteem, and QOL). Besides overcoming the limitations of past research, recommendations for future research included: (a) extending the research beyond breast and early-stage cancers; (b) comparing and integrating physical exercise with other QOL interventions; (c) examining resistance exercises, the timing of the intervention, and contextual factors; (d) expanding the breadth of the QOL indicators examined; and (e) investigating the rates and determinants of recruitment and adherence to an exercise program following cancer diagnosis.

Utility of the theory of planned behavior for understanding exercise during breast cancer treatment

Preliminary evidence indicates that physical exercise may be an effective strategy for helping cancer patients cope with the negative side-effects of their treatment. The purpose of the present study was to examine the utility of the theory of planned behavior in understanding cancer patients' motivation to exercise during treatment. A total of 164 women who had been diagnosed with breast cancer within the previous 2 years participated in the study. A retrospective design was used wherein these women were asked to recall their beliefs and exercise behavior during cancer treatment using a self-administered, mailed questionnaire. Results showed that: (1) the salient beliefs of breast cancer patients concerning exercise were different from those of the healthy population; (2) intention and perceived behavioral control were significant determinants of exercise during cancer treatment; and, (3) attitude and subjective norm were significant determinants of intention. It was concluded that the theory of planned behavior may be a viable framework on which to base interventions designed to promote exercise during cancer treatment. The results of this study are preliminary, however, and more sophisticated research designs to examine this question are warranted.

Transtheoretical Model: examining adolescent exercise behavior

PURPOSE

The entire Transtheoretical Model, consisting of stages of change, processes of change, self-efficacy, and decisional balance, was tested for its applicability to understanding exercise behavior in an adolescent population.

METHODS

Students (n = 819) from five community high schools (Grades 9-12) completed self-administered questionnaires, all of which were adapted from previous literature. Stage of exercise behavior change served as the dependent variable.

RESULTS

Distribution of the sample across the stages was: precontemplation, n = 17 (2.1%); contemplation, n = 34 (4.2%); preparation, n = 235 (28.7%); action, n = 129 (15.7%); and maintenance, n = 404 (49.3%). Univariate analyses of variance (p < 0.0038) followed up with Tukey's post-hoc analyses revealed that all of the constructs differed significantly across stages. Profile analysis indicated that pros and cons intersected in the action stage using t scores; however, when analyzing raw scores, this intersection was found to be in the precontemplation stage.

DISCUSSION

Preliminary evidence was found for the applicability of the Transtheoretical Model to adolescents. The low rate of adolescents in the precontemplation and contemplation stages was not deemed a major limitation, owing to the purpose of the investigation.

The lifetime total physical activity questionnaire: development and reliability

OBJECTIVE

To develop and test the intra-rater reliability of an interview-administered questionnaire that assesses lifetime patterns of total physical activity including occupational, household, and exercise/sports activities.

METHODS

The questionnaire was developed and pretested using cognitive interviewing techniques on a sample of women with and without previous breast cancer diagnoses. A pilot study was conducted with 115 women who were interviewed twice, 6 to 8 wk apart by interviewers trained in cognitive interviewing methods. Respondents used recall calendars to record their education, occupations, life events, and physical activity patterns before the interviews. Interviewers helped respondents recall their lifetime exposures, including their occupational, household, and exercise/sports activities, using these calendars and memory-probing strategies. Activity levels were estimated as the average number of hours of activity per week over different time periods. Means and correlation coefficients were estimated and compared for the two time periods.

RESULTS

The questionnaire was found to be highly reliable. The test-retest correlations for hours per week spent in total lifetime physical activity was 0.74, for lifetime occupational activity was 0.87, for household activity was 0.77, and for exercise/sports activities was 0.72.

CONCLUSIONS

This is the first questionnaire to measure lifetime physical activity by collecting data on each type of physical activity separately over lifetime and by measuring frequency, intensity, and duration of each activity. It is also the first physical activity questionnaire to be developed, refined, and administered using cognitive-based methods employed in survey research. Respondents were able to reliably recall their lifetime physical activity patterns. This instrument can be used for any disease outcome for which physical activity may be a risk factor.