Predictors of Adherence to Different Volumes of Exercise in the Breast Cancer and Exercise Trial in Alberta.

BACKGROUND: Exercise demonstrates a dose-response effect on many health outcomes; however, adhering to higher doses of exercise can be challenging, and the predictors of adherence may differ based on exercise volume. PURPOSE: To examine the predictors of adherence to two different volumes of aerobic exercise within the Breast Cancer and Exercise Trial in Alberta (BETA). METHODS: In BETA, we randomized 400 inactive but healthy postmenopausal women to either a moderate volume (150 min/week) or a high volume (300 min/week) of aerobic exercise for 1 year. We collected data on several predictors of exercise adherence at baseline and used linear and mixed-effect models to determine predictors of exercise adherence to exercise volume and overall. RESULTS: Adherence was higher in the moderate-volume group (84.5%) compared with the high-volume group (75.2%; p < .001). There were no statistically significant interactions between predictors of exercise adherence and exercise volume. Overall, we found that exercise adherence was predicted by randomization group, body mass index (BMI), employment status, and physical health. Adherence was 8.6% lower in the high-volume versus moderate-volume group, 6.7% lower for women working full time versus not, 0.8% lower per BMI increase of 1 kg/m2, and 0.5% higher per unit of physical health. CONCLUSIONS: Adherence to high-volume aerobic exercise was more challenging than for moderate-volume aerobic exercise, but the predictors of adherence were similar. Moreover, few factors were major predictors of exercise adherence in this setting suggesting that well-controlled efficacy trials that produce high adherence rates may reduce the influence of individual characteristics on exercise adherence. TRIAL REGISTRATION: NCT1435005.

Correlates of meeting the combined and independent aerobic and strength exercise guidelines in hematologic cancer survivors.

BACKGROUND: Most previous research on the correlates of physical activity has examined the aerobic or strength exercise guidelines separately. Such an approach does not allow an examination of the correlates of meeting the combined guidelines versus a single guideline, or one guideline versus the other. Here, we report the prevalence and correlates of meeting the combined and independent exercise guidelines in hematologic cancer survivors (HCS). METHODS: In a population-based, cross-sectional survey of 606 HCS from Alberta, Canada using a mailed questionnaire, we obtained separate assessments of aerobic and strength exercise behaviors, as well as separate assessments for motivations, regulations, and reflective processes using the multi-process action control framework (M-PAC). RESULTS: Overall, 22% of HCS met the combined exercise guideline, 22% met aerobic-only, 10% met strength-only, and 46% met neither exercise guideline. HCS were more likely to meet the combined guideline over the aerobic-only guideline if they had no children living at home, and over both the aerobic and strength-only guidelines if they had completed university. As hypothesized, those meeting the combined guideline also had a more favorable strength-specific M-PAC profile (i.e., motivations, regulations, and reflective processes) than those meeting the aerobic-only guideline, and a more favorable aerobic-specific M-PAC profile than those meeting the strength-only guideline. Interestingly and unexpectedly, HCS meeting the combined guidelines also reported significantly greater aerobic-specific perceived control, planning, and obligation/regret than those meeting the aerobic-only guideline, and greater strength-specific perceived control, planning, and obligation/regret than those meeting the strength-only guideline. CONCLUSIONS: Few HCS are meeting the combined exercise guidelines. M-PAC based variables are strong correlates of meeting the combined guidelines compared to aerobic or strength only guidelines. Strategies to help HCS meet the combined guidelines may need to promote more favorable behavioral regulations and reflective processes for both types of exercise rather than just the type of exercise in which HCS are deficient.

Impact of resistance and aerobic exercise on sarcopenia and dynapenia in breast cancer patients receiving adjuvant chemotherapy: a multicenter randomized controlled trial.

The purpose of this study was to conduct an exploratory analysis of the START examining the effects of resistance exercise training (RET) and aerobic exercise training (AET) on sarcopenia, dynapenia, and associated quality of life (QoL) changes in breast cancer (BC) patients receiving adjuvant chemotherapy. Participants were randomized to usual care (UC) (n = 70), AET (n = 64), or RET (n = 66) for the duration of chemotherapy. Measures of sarcopenia [skeletal muscle index (SMI)] and dynapenia [upper extremity (UE) and lower extremity (LE) muscle dysfunction (MD)] were normalized relative to age-/sex-based clinical cut-points. QoL was assessed by the Functional Assessment of Cancer Therapy-Anemia (FACT-An) scales. At baseline, 25.5 % of BC patients were sarcopenic and 54.5 % were dynapenic with both conditions associated with poorer QoL. ANCOVAs showed significant differences favoring RET over UC for SMI (0.32 kg/m(2); p = 0.017), UE-MD (0.12 kg/kg; p < 0.001), and LE-MD (0.27 kg/kg; p < 0.001). Chi-square analyses revealed significant effects of RET, compared to UC/AET combined, on reversing sarcopenia (p = 0.039) and dynapenia (p = 0.019). The reversal of sarcopenia was associated with clinically relevant improvements in the FACT-An (11.7 points [95 % confidence interval (CI) -4.2 to 27.6]), the Trial Outcome Index-Anemia (10.0 points [95 % CI -4.0 to 24.1]), and fatigue (5.3 points [95 % CI -1.5 to 12.1]). Early-stage BC patients initiating adjuvant chemotherapy have higher than expected rates of sarcopenia and dynapenia which are associated with poorer QoL. RET during adjuvant chemotherapy resulted in the reversal of both sarcopenia and dynapenia; however, only the reversal of sarcopenia was associated with clinically meaningful improvements in QoL.

Motivation for Different Types and Doses of Exercise During Breast Cancer Chemotherapy: a Randomized Controlled Trial.

BACKGROUND: Exercise is beneficial for breast cancer patients during chemotherapy, but their motivation to perform different types and doses of exercise is unknown. PURPOSE: The purpose of this study was to examine the anticipated and experienced motivation of breast cancer patients before and after three different exercise programs during chemotherapy. METHODS: Breast cancer patients initiating chemotherapy (N = 301) were randomized to a standard dose of 25-30 min of aerobic exercise, a higher dose of 50-60 min of aerobic exercise, or a combined dose of 50-60 min of aerobic and resistance exercise. Patient preference and motivational outcomes from the theory of planned behavior (i.e., perceived benefit, enjoyment, support, difficulty, and motivation) were assessed before and after the interventions. RESULTS: At pre-randomization, breast cancer patients were significantly (p < 0.001) more likely to prefer the combined program (80.1 %); however, after the interventions there was a significant (p < 0.001) increase in the number of patients preferring the high volume program and having no preference. At pre-randomization, breast cancer patients anticipated more favorable motivational outcomes for the combined program and less favorable motivational outcomes for the high volume program (all p < 0.001). After the interventions, the motivational outcomes experienced exceeded the anticipated motivational outcomes significantly more in the high volume group than the standard or combined groups. CONCLUSIONS: Anticipated motivational outcomes for different types and doses of exercise during chemotherapy varied considerably at pre-randomization, but the motivational outcomes experienced after the three interventions were similar. Clinicians can recommend any of the three exercise interventions to breast cancer patients knowing that positive motivational outcomes will result. Clinicaltrials.gov identifier: NCT00249015 .

Predictors of adherence to different types and doses of supervised exercise during breast cancer chemotherapy.

BACKGROUND: Exercise is beneficial for breast cancer patients during chemotherapy but adherence to different types and doses of exercise is a challenge. The purpose of this study was to examine predictors of adherence to different types and doses of exercise during breast cancer chemotherapy in a multicenter randomized controlled trial. METHODS: Breast cancer patients in Edmonton, Vancouver, and Ottawa, Canada receiving chemotherapy (N = 301) were randomized to a standard dose of 25-30 minutes of aerobic exercise (STAN), a higher dose of 50-60 minutes of aerobic exercise (HIGH), or a higher dose of 50-60 minutes of combined aerobic and resistance exercise (COMB). Predictors included demographic, medical, fitness, and quality of life variables. Exercise adherence was measured as the percentage of supervised exercise sessions completed. RESULTS: Overall adherence to the supervised exercise sessions was 73% (SD = 24%). In a multivariate regression model, six independent predictors explained 26.4% (p < 0.001) of the variance in exercise adherence. Higher exercise adherence was achieved by breast cancer patients in Vancouver (p < 0.001), with fewer endocrine symptoms (p = 0.009), randomized to STAN (p = 0.009), with fewer exercise limitations (p = 0.009), receiving shorter chemotherapy protocols (p = 0.015), and with higher VO2peak (p = 0.017). Disease stage (p for interaction = 0.015) and body mass index (p for interaction = 0.030) interacted with group assignment to predict adherence. For disease stage, patients with stage I/IIa disease adhered equally well to all three exercise interventions whereas patients with stage IIb/III disease adhered better to the STAN intervention than the two higher dose exercise interventions. For body mass index, healthy weight patients adhered equally well to all three exercise interventions whereas overweight patients adhered best to STAN and worst to COMB; and obese patients adhered best to STAN and worst to HIGH. CONCLUSIONS: Determinants of exercise adherence in breast cancer patients receiving chemotherapy are multidisciplinary and may vary by the exercise prescription.

Pulmonary Hypertension and Exercise.

Cardiopulmonary exercise testing can be a useful tool for clinicians working with pulmonary hypertension (PH) patients. Exercise magnifies numerous cardiopulmonary decompensations, which can help inform diagnoses, assess degrees of physical impairment, evaluate exertional dyspnea, and estimate prognoses for PH patients. Supervised exercise training also holds promise in PH, because it is safe for patients and feasible and may improve key prognostic outcomes that relate to improvements in quality of life and survival. Still, few clinical trials have evaluated the potential therapeutic effects of exercise training, and future trials may benefit from integrating programming that focuses on light-intensity endurance, strength, and respiratory training.

Social Cognitive Effects and Mediators of a Pilot Telephone Counseling Intervention to Increase Aerobic Exercise in Hematologic Cancer Survivors.

BACKGROUND: Theory-based telephone counseling exercise (TCE) interventions can increase aerobic exercise behavior in cancer survivors. Few studies, however, assess intervention effects on social cognitive variables. Here, the authors examined changes in social cognitive variables from a TCE intervention based on the multi-process action control framework in hematologic cancer survivors. METHODS: A total of 51 hematologic cancer survivors were randomized to weekly TCE (n = 26) or self-directed exercise (n = 25) for 12 weeks. Participants self-reported on demographic and cancer variables, as well as motivational, regulatory, and reflexive ratings pertaining to aerobic exercise at baseline and post-intervention. RESULTS: Small-to-large between-group differences in all variables favored the TCE group. The most prominent effects were noted for differences in coping planning (adjusted mean between-group difference [MBGDadj] = 1.4, 95% confidence interval [CI], 0.7 to 2.2, d = 1.04), instrumental attitude (MBGDadj = 0.5, 95% CI, 0.1 to 1.0, d = 1.11), affective attitude (MBGDadj = 0.6, 95% CI, 0.1 to 1.2, d = 0.71), and perceived opportunity (MBGDadj = 0.4, 95% CI, -0.3 to 1.2, d = 0.50). Changes in coping planning (b = 24.98, ß = 0.18, 95% CI, -0.03 to 0.56), perceived opportunity (b = 17.95, ß = 0.13, 95% CI, 0.01 to 0.36), exercise identity (b = 17.43, ß = 0.12, 95% CI, -0.05 to 0.41), and habit (b = 14.64, ß = 0.10, 95% CI, -0.01 to 0.42) accounted for the largest mediating effects on aerobic exercise behavior. CONCLUSIONS: Multi-process action control framework-based TCE interventions may strengthen motivational, regulatory, and reflexive profiles that translate into increased aerobic exercise behavior in hematologic cancer survivors.

Feasibility and preliminary efficacy of an exercise telephone counseling intervention for hematologic cancer survivors: a phase II randomized controlled trial.

BACKGROUND: Supervised exercise interventions produce the largest improvements in patient-reported outcomes in cancer survivors but their scalability has been questioned. Telephone counseling has been proposed as a more feasible alternative but its impact on exercise behavior and health outcomes have been modest. Basing telephone counseling exercise (TCE) interventions on the theoretical advances described in the multi-process action control framework (M-PAC) may improve these outcomes. PURPOSE: To assess the feasibility and preliminary efficacy of a M-PAC-based TCE intervention for increasing aerobic exercise behavior in hematologic cancer survivors (HCS). METHODS: We recruited 51 HCS who were randomized to either a weekly TCE group (n = 26) or a self-directed exercise (SDE) group (n = 25). Participants completed online measures of self-reported aerobic exercise behavior, quality of life (QoL), fatigue, and program satisfaction at baseline and post-intervention (12 weeks). RESULTS: Adherence to the TCE intervention was 93% and retention was 100%. Participants receiving TCE increased their weekly aerobic exercise by 218 min compared to 93 min in the SDE group [mean-adjusted between-group difference (MBGDadj) = 139, 95%CI = 65 to 213, p < .001, effect size (d) = 2.19]. Clinically meaningful QoL improvements favored the TCE group for mental health (MBGDadj = 3.7, 95%CI = - 0.4 to 7.9, p = .08, d = 0.42) and mental health component (MBGDadj = 3.6, 95%CI = - 0.8 to 8.1, p = .10, d = 0.35) subscales. CONCLUSIONS: The 12-week TCE intervention substantially increased exercise behavior and may have meaningfully improved QoL in HCS. IMPLICATIONS FOR CANCER SURVIVORS: Though more definitive trials are needed, remote TCE interventions based on the M-PAC may improve exercise behavior and QoL in HCS and perhaps other cancer survivor groups. TRIAL REGISTRATION NUMBER: Clinical Trials ID: NCT03052777.

Understanding strength exercise intentions and behavior in hematologic cancer survivors: an analysis of the intention-behavior gap.

BACKGROUND: Strength exercise improves many health outcomes in cancer survivors but the prevalence and correlates of strength exercise have not been well-described. Moreover, no study has examined the critical intention-behavior gap for exercise in cancer survivors. PURPOSE: The aims of this study are to quantify the intention-behavior gap for strength exercise in hematologic cancer survivors (HCS) and examine correlates of both intention formation and translation using the multi-process action control framework (M-PAC). METHODS: A random sample of 2100 HCS in Alberta, Canada, were mailed a survey assessing strength exercise behavior, the M-PAC, and demographic/medical variables. Separate logistic regressions were used to analyze the relationships between the correlates and intention formation and translation. RESULTS: Surveys were completed by 606 HCS with 58 % (n = 353) intending to do strength exercise. HCS who were not retired (OR = 1.56, p = 0.001), were highly educated (OR = 1.32, p = 0.001), and had a favorable attitude (OR = 1.56, p < 0.001), descriptive norm (OR = 1.38, p = 0.006), injunctive norm (OR = 1.45, p = 0.004), and perceived control (OR = 1.38, p < 0.001), were more likely to form an exercise intention. Of those with an exercise intention, 51 % (n = 181) reported regular strength exercise. HCS with a detailed plan (OR = 1.86, p < 0.001), favorable attitude (OR = 1.68, p = 0.001), sense of obligation (OR = 1.38, p = 0.010), and self-regulated their affinity for competing activities (OR = 1.35, p = 0.012), were more likely to translate their intention into behavior. CONCLUSION: Just over half of HCS intended to do strength exercise and only half of intenders translated that intention into behavior. IMPLICATIONS FOR CANCER SURVIVORS: Interventions targeting both intention formation and translation may provide the best approach for increasing strength exercise in HCS.

Explaining the Aerobic Exercise Intention-behavior Gap in Cancer Survivors.

OBJECTIVES: We sought to quantify the aerobic exercise intention-behavior gap in hematologic cancer survivors (HCS), and examine the correlates of intention formation and translation using the multi-process action control framework. METHODS: HCS (N = 606) completed a survey reporting their aerobic exercise motivation and behavior. The correlates of intention formation and translation were analyzed using separate logistic regressions. RESULTS: Overall, 71% (N = 428/606) of HCS intended to do aerobic exercise, 44% (N = 267/606) met aerobic exercise guidelines, and 60% of intenders (N = 256/428) translated their intention into aerobic exercise. Attitude (OR = 1.9), perceived control (OR = 1.5), younger age (OR = 2.0), and higher education (OR = 2.1) explained intention formation (all ps ≤ .001). A sense of obligation/regret (OR = 2.8), self-regulation over alternative activities (OR = 1.6), attitude (OR = 2.0), perceived control (OR = 1.7), planning (OR = 1.7), being female (OR = 2.0), and younger (OR = 3.0) explained intention translation (all ps < .005). CONCLUSIONS: Forming an intention is insufficient for many HCS to meet aerobic exercise guidelines. Interventions targeting the determinants of both intention formation and translation may be most effective in promoting aerobic exercise in cancer survivors.