BACKGROUND Understanding the longer-term exercise behavior of patients with breast cancer after chemotherapy is important to promote sustained exercise. The purpose of the current study was to report the longer-term patterns and predictors of exercise behavior in patients with breast cancer who exercised during chemotherapy. METHODS In the Combined Aerobic and Resistance Exercise (CARE) Trial, 301 patients with breast cancer were randomized to three different exercise prescriptions during chemotherapy. Exercise behaviors after chemotherapy were self-reported at 6-, 12-, and 24-month follow-up. Exercise patterns were identified by categorizing patients according to which exercise guideline they were meeting (neither, aerobic only, resistance only, or combined) at each of the three follow-up timepoints (64 possible patterns). Predictors of longer-term exercise behavior included physical fitness, patient-reported outcomes, and motivational variables from the theory of planned behavior assessed at postintervention (postchemotherapy). Univariate and multivariate stepwise multinomial logistic regression and linear regression were used for statistical analyses. RESULTS A total of 264 (88%) participants completed all three follow-up exercise behavior assessments and exhibited 50 different exercise patterns. Postintervention aerobic fitness was the most consistent predictor of longer-term exercise behavior at all three timepoints. For example, higher aerobic fitness (per 1 ml/kg/min) predicted better adherence to the "aerobic only" (OR = 1.09; p = 0.005) and "combined" (OR = 1.12; p < 0.001) guidelines compared to "neither" guideline at 6-month follow-up. Additionally, higher postintervention muscular strength (per 1 kg) was associated with better adherence to the "resistance only" (OR = 1.07; p = 0.025) and "combined" (OR = 1.08; p < 0.001) guidelines compared to "neither" guideline at 24-month follow-up. Finally, lower perceived difficulty (per 1 scale point) was associated with better adherence to the "combined" (OR = 0.62; p = 0.010) and "aerobic only" (OR = 0.58; p = 0.002) guideline compared to the "neither" guideline at the 24-month follow-up. CONCLUSIONS Our study is the first to show that the longer-term exercise patterns of patients with breast cancer who exercised during chemotherapy are diverse and predicted by physical fitness and motivational variables after chemotherapy. Our novel implications are that improving physical fitness during chemotherapy and applying motivational counseling after chemotherapy may improve longer-term exercise behavior in patients with breast cancer. TRIAL REGISTRATION (NCT00249015).

中文翻译：

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在乳腺癌化疗期间进行有监督的锻炼计划后的24个月随访中，锻炼行为的模式和预测指标。

背景技术了解化疗后乳腺癌患者的长期运动行为对促进持续运动很重要。本研究的目的是报告在化疗期间运动的乳腺癌患者的长期行为模式和运动行为的预测指标。方法在有氧抵抗运动联合试验（CARE）中，将301名乳腺癌患者在化疗期间随机分为三种不同的运动处方。化疗后的运动行为在6、12和24个月的随访中自我报告。通过在三个随访时间点（64个可能的模式）中根据患者所遵循的运动指南（既无氧运动，仅抗阻力或联合运动）对患者进行分类来确定运动模式。长期锻炼行为的预测因素包括身体健康状况，患者报告的结局以及干预后评估的计划行为理论（化疗后）的动机变量。使用单变量和多元逐步多项式逻辑回归和线性回归进行统计分析。结果共有264名（88％）参与者完成了所有三项跟进运动行为评估，并展示了50种不同的运动方式。干预后有氧健身是所有三个时间点长期运动行为的最一致预测指标。例如，较高的有氧健身度（每1 ml / kg / min）预测与“仅有氧运动”（OR = 1.09； p = 0.005）和“联合”（OR = 1.12； p <0.001）准则相比，更好地遵守了“都不是” 6个月随访的指南。此外，干预后较高的肌肉力量（每1 kg）与“仅”抗性（OR = 1.07； p = 0.025）和“综合”（OR = 1.08； p <0.001）指南的坚持性相关，而与“无” 24个月随访的指南。最后，与“两者都不”相比，较低的感知难度（每1个标度点）与更好地遵守“综合”（OR = 0.62； p = 0.010）和“仅有氧”（OR = 0.58； p = 0.002）准则相关”在24个月随访中的指导原则。结论我们的研究首次表明，在化疗期间运动的乳腺癌患者的长期运动模式是多种多样的，并且可以通过化疗后的体能和动机变量来预测。我们的新颖含义是，在化疗过程中提高身体适应性，并在化疗后应用动机咨询可以改善乳腺癌患者的长期运动行为。试用注册（NCT00249015）。