Treatment side affects exercising microvascular oxygenation response in active breast cancer survivors: A pilot study.

Cancer treatment is associated with cardiovascular toxicity, skeletal muscle dysfunction and interruptions in mitochondrial respiration. Microvascular oxygenation responses, measured via near-infrared spectroscopy (NIRS), at peak exercise intensity has previously been associated with aerobic capacity. Specifically, the greater magnitude of microvascular deoxygenation observed at peak exercise intensity has been associated with higher aerobic capacity. Therefore, a pilot study investigated if diagnosis side (uninvolved side, treatment side) and/or exercise side (paddle side, non-paddle side) affected microvascular oxygenation responses at peak intensity during paddle exercise. Thirty-three breast cancer survivors (age = 57 ± 9 years, height = 1.64 ± 0.05 m, weight = 76.5 ± 15.6 kg, 7 ± 7 years since treatment) who also competed as dragon boat racers performed a unilateral (paddle), discontinuous graded exercise test (2-min exercise, 1-min rest) on a rowing ergometer to volitional fatigue. Tissue oxygenation saturation (StO2DIFF ) and total haemoglobin concentration (total[heme]DIFF ) responses at peak exercise intensity were measured bilaterally from the posterior deltoids using NIRS. Two-way analysis of variance determined if diagnosis side and/or exercise side effected StO2DIFF or total[heme]DIFF . Diagnosis side elicited a moderate effect (effect size = 0.66) on StO2DIFF , as the treatment side deoxygenated less (-6.0 ± 14.7 ∆BSL) compared to the uninvolved side (-16.9 ± 16.9 ∆BSL) at peak exercise intensity. No other significant main effects or interactions were observed for StO2DIFF or total[heme]DIFF . The pilot findings suggest that the ability of the exercising muscle to use oxygen for the purpose of mitochondrial oxidative respiration may be impaired on the treatment side.

Effective Translation of Research to Practice: Hospital-Based Rehabilitation Program Improves Health-Related Physical Fitness and Quality of Life of Cancer Survivors.

BACKGROUND: Although exercise has been widely established as an efficacious rehabilitative therapy for cancer survivors in rigorously designed research studies, demonstration of translation of this research into clinical oncology practice is needed. The purpose of this study was to evaluate the effectiveness of a real-world cancer rehabilitation program implemented within a healthcare setting. PATIENTS AND METHODS: This study involved 299 adult cancer survivors enrolled in a hospital-based, supervised, individualized, cancer rehabilitation program. A retrospective review of the 132 participants who completed the follow-up assessment was performed. Sixty-minute sessions consisting of aerobic, resistance, flexibility, and relaxation exercises were performed twice weekly. Questionnaires and fitness assessments were administered at enrollment and after 24 sessions by exercise physiologists. Change in a number of health-related physical fitness and patient-reported outcomes and the influence of baseline characteristics on program outcomes were assessed. RESULTS: There were no baseline differences between those who completed the follow-up assessment and those who withdrew. Statistically and/or clinically meaningful improvements occurred in functional capacity, blood pressure, muscular endurance, flexibility, health-related quality of life, and fatigue, but not in body composition. Age, marital status, radiation treatment status, exercise frequency before diagnosis, smoking status, and alcohol consumption frequency influenced functional capacity and/or quality-of-life changes. CONCLUSIONS: Adoption of cancer rehabilitation as a standard part of oncology care may improve cancer survivors' health and well-being.

A Feasibility Study Related To Inactive Cancer Survivors Compared with Non-Cancer Controls during Aerobic Exercise Training.

Cancer survivors (CA) tend to demonstrate metabolic, cardiac, and ventilatory alterations due to previous chemotherapy and radiation that may impair adaptability following aerobic exercise training. Exercise training adaptations of CA finished with primary treatment compared to non-cancer participants (NC) have not yet been extensively elucidated. Thus, the present study compared physiologic responses of CA versus NC following a low-to-moderate intensity, 8-wk aerobic training program. Thirty-seven previously sedentary participants (CA: n = 14, 12 females; NC: n = 23, 19 females) with no heart or metabolic disease did not differ in age, height, weight, and body mass index (51 ± 2 y, 1.66 ± 0.02 m, 83.8 ± 3.2 kg, and 30.5 ± 1 kg·m-2). Each participant underwent baseline, 3-, 6-, and 8-wk VO2peak treadmill testing using the USAFSAM protocol and walked on a treadmill three times per week at 80-90% of ventilatory threshold (VT) for approximately 40-min·session-1. Variables obtained on the VO2peak tests included: HR at stage 2 (HR@stage2), rating of perceived exertion at stage 2 (RPE@stage2), lactate threshold (LT), ventilatory threshold (VT), salivary cortisol at 30-min post VO2peak test (SC@30-minPost),VO2peak level, time of fatigue (TOF), and maximal heart rate (HRmax). NC had significantly (p < 0.05) higher VO2peak, TOF, and HRmax at baseline, 3- and 6-wks of training but not at 8-wks. There were no differences between groups on RPE@stage2 except at baseline (p < 0.05). A significant (p < 0.05) interaction was observed only for RPE@stage2 with CA rating their initial RPE significantly greater at baseline versus NC. CA notably improved submaximal and maximal exercise capacity during 8 weeks of aerobic training and did not show altered adaptability compared to NC. We suggest prescribing aerobic exercise training at low/moderate intensity and duration initially, with progressive increases in duration and intensity after approximately 8-weeks. If available and supported, we advise clinicians to utilize submaximal threshold concepts obtained from cardiopulmonary exercise testing to prescribe more precise aerobic exercise training parameters.

Dragon Boat training exerts a positive effect on myocardial function in breast cancer survivors.

INTRODUCTION: Dragon Boat training is often suggested to control upper limb edema in breast cancer (BC) survivors, but little information is available regarding the cardiac impact of such activity. The present study evaluates this aspect during a 4-year follow-up of BC survivors. MATERIAL AND METHODS: From 2006 to 2010, 55 women diagnosed with BC in 2005, treated with adjuvant therapy without evidence of metastases, were enrolled for competitive Dragon Boat training. They underwent ergometric tests yearly, and 2D echocardiography to evaluate hemodynamic, morphological and functional cardiac parameters. RESULTS: The data were compared with those from a group of 36 healthy women (HW). Both groups maintained normal systolic function throughout the period, with Cardiac Mass index, Body Mass Index and Ejection Fraction values being higher in HW. At the onset of the study, the diastolic function of BC survivors was normal though compatible with initial diastolic dysfunction when compared to the diastolic function of HW. After 4 years of competitive activity, the diastolic parameters improved in both groups and particularly in BC survivors (A peak: from 68.5 ± 15.1 cm/s to 50 ± 14.1 cm/s, p < 0.05; Ea: from 9.3 ± 2 cm/s to 11.89 ± 1.7 cm/s, p < 0.001). CONCLUSIONS: BC survivors experienced a significant improvement in diastolic function after 4 years of Dragon Boat training. Dragon Boat training impacts favorably on the myocardial performance in patients previously treated with chemotherapy. These results support the positive role of sport activity in myocardial function of BC survivors.

Cardiorespiratory and neuromuscular deconditioning in fatigued and non-fatigued breast cancer survivors.

PURPOSE: Fatigue is one of the most commonly reported side effects during treatment for breast cancer and can persist following treatment completion. Cancer-related fatigue after treatment is multifactorial in nature, and one hypothesized mechanism is cardiorespiratory and neuromuscular deconditioning. The purpose of this study was to compare cardiorespiratory and neuromuscular function in breast cancer survivors who had completed treatment and met the specified criteria for cancer-related fatigue and a control group of breast cancer survivors without fatigue. METHODS: Participants in the fatigue (n = 16) and control group (n = 11) performed a maximal exercise test on a cycle ergometer for determination of peak power, power at lactate threshold, and VO(2) peak. Neuromuscular fatigue was induced with a sustained submaximal contraction of the right quadriceps. Central fatigue (failure of voluntary activation) was evaluated using twitch interpolation, and peripheral fatigue was measured with an electrically evoked twitch. RESULTS: Power at lactate threshold was lower in the fatigue group (p = 0.05). There were no differences between groups for power at lactate threshold as percentage of peak power (p = 0.10) or absolute or relative VO(2) peak (p = 0.08 and 0.33, respectively). When adjusted for age, the fatigue group had a lower power at lactate threshold (p = 0.02) and absolute VO(2) peak (p = 0.03). There were no differences between groups in change in any neuromuscular parameters after the muscle-fatiguing protocol. CONCLUSIONS: Findings support the hypothesis that cardiorespiratory deconditioning may play a role in the development and persistence of cancer-related fatigue following treatment. Future research into the use of exercise training to reduce cardiorespiratory deconditioning as a treatment for cancer-related fatigue is warranted to confirm these preliminary findings.

Comparison of physiological response to cardiopulmonary exercise testing among cancer survivors and healthy controls.

Selected physiological responses, including lactate kinetics, to cardiopulmonary exercise testing (CPET) were evaluated among a group of cancer survivors (CS, n = 55) and healthy controls (HC, n = 213). It was uncertain if lactate testing in a group of cancer survivors could provide useful information about training intensity. It was hypothesized that chemotherapy, radiation, surgery, physical inactivity or some combination thereof would alter the normal lactate kinetics (curvilinearity) in the relationship of lactate concentration versus power. Physiologic responses of CS (heart rate, blood pressure, O(2) saturation, RPE, lactate, VO(2peak), and peak power) during cycle ergometry were compared to HC. Comparisons (t tests and Chi-square) were made between the groups and shape of lactate plots were analyzed for determination of a breakpoint. Multiple logistical regressions were then utilized to identify factors related to the inability to determine lactate breakpoints. Lactate breakpoints were common to all but one HC whereas among the CS there was a small subset of subjects (n = 5) who did not show a lactate breakpoint. Group differences indicated that female CS were significantly older, had greater BMI's, and lower work capacity than HC. Males CS had significantly lower work capacity than HC. Multiple logistical regression analyses, in all instances, yielded no statistically significant models predictive of the inability to determine a lactate breakpoint. In this sample of CS and HC, physiological responses and lactate kinetics during CPET were similar while work capacity among the CS was lower. Because lactate breakpoints were found, lactate threshold could be determined for all but a few individuals. For those working with CS, CPET with ECG monitoring and lactate threshold measures should be considered for those wishing for precise and safe training intensities.

Individualized 12-week exercise training programs enhance aerobic capacity of cancer survivors.

Changes in aerobic capacity were evaluated after 12 weeks of training among a motivated heterogeneous group of cancer survivors (N = 54 [41 women and 13 men]), living at moderate altitude. Changes in power at lactate threshold (PT(lact)), peak power (P(peak)), and peak oxygen uptake (VO(2) peak) were evaluated in this group (average age, 53.8 + or - 10.8 years) that completed a minimum of 12 weeks of an individualized exercise program (on average 5 days x week(-1) for 47.5 + or - 17.2 min x session(-1)). Daily exercise duration was based on the goals and functional capacity of each individual. Training intensity for each subject was based on heart rate (HR) value at lactate threshold (T(lact)) obtained during a symptom-limited cardiopulmonary exercise test. Intensity was categorized into 5 ranges: recovery (60%-80% HR T(lact)); endurance (80%-100% HR T(lact)); threshold (100%-105% HR T(lact)); intervals (105%-115% HR T(lact)); and maximal efforts (> or = 115% HR T(lact)). Overall compliance with the exercise prescription was approximately 72% and subjects reported exercising within the 5 training ranges, 12.1%, 63.9%, 18.6%, 4.2%, and 1.2% of the time, respectively. After training, PT(lact) increased 9.5% (121.8 + or - 43.5 vs 133.2 + or - 34.1 W; P < 0.05), P(peak) increased 12.6% (175.5 + or - 55.6 vs 195.6 + or - 54.2 W; P < 0.05) and VO(2) peak increased 11.4% (33.4 + or - 12.5 vs 37.2 + or - 10.4 mL x kg(-1) x min(-1); P < 0.05). The results of this research indicate that: 1) cardiopulmonary exercise testing with lactate threshold determination was safe and effective in the evaluation and exercise prescription phase for a group of cancer survivors and 2) a training program based on 2 higher intensity workouts per week can elicit significant changes in aerobic capacity of a diverse group of cancer survivors.

Exercise capacity of a breast cancer survivor: a case study.

PURPOSE: The processes by which we assess, create an individualized exercise program, and monitor training of a breast cancer survivor who was participating in a fitness plan during and after surgery, chemotherapy, and radiation treatments were examined over a 391-d period. CASE STUDY: A 57-yr-old female was diagnosed with stage I breast cancer (approximately 1.2 cm diameter, estrogen positive, HER2/neu negative) with no lymph node involvement. After lumpectomy and axillary node dissection, the client completed chemotherapy treatment (cyclophosphamide, methotrexate, 5-fluorouracil (CMF)) followed by 33 bouts of radiation therapy. Assessment (body composition, VO2max, lactate threshold, pulmonary function testing) was measured 4 d postdiagnosis and 2 months after treatments had ended. The client kept a daily log of exercise, average heart rate, and rating of perceived exertion in each exercise session. RESULTS: Over 391 calendar days, the client exercised 343 days (88%) and completed 424 exercise sessions. The client's body composition (15.1%) and body weight (41.4 kg) remained stable for the entire period. There was a significant decrease in VO2max (-7.8%) before and after treatment (56.4 to 52.0 mL x kg(-1) x min(-1), respectively). During the treatment phase (6.8 months), the client averaged 1.19 exercise sessions per day, with an average duration of 48.1 +/- 25.2 min at approximately 57% of VO2max (approximately 32 mL x kg(-1) x min(-1)). Posttreatment (approximately 6.2 months), the client averaged 1.32 exercise sessions per day, with an average duration of 69.3 +/- 38.5 min at approximately 59.6% VO2max (approximately 31.2 mL x kg(-1) x min(-1)). Pre- and posttreatment exercise durations were significantly different (P < 0.01). CONCLUSIONS: A cancer survivor who engaged in a medically supervised and proactive fitness plan starting from the day of diagnosis maintained a realistic level of physiologic function during and after cancer treatment.

Efficacy of cycling training based on a power field test.

The efficacy of an 8-minute field test to prescribe exercise intensity and assess changes in fitness was evaluated before and after 8 weeks of indoor cycling, and the results were confirmed by laboratory assessment. Changes in maximal steady-state power (MSSP), power at lactate threshold (PT(lact)), maximal power (Pmax), and maximal oxygen uptake (VO2max) were measured on 56 participants (20 women, 36 men; mean +/- SD. 46.5 +/- 10.0 years) who completed 1-hour, biweekly indoor stationary cycling classes on their own road bike outfitted with a Power Tap Pro power meter. The MSSP was defined as the average power during an 8-minute field test, which was administered at the beginning (pre) and end (post) of the training intervention. Individual training ranges were calculated from the pre-MSSP in accordance with Carmichael Training Systems. Laboratory assessments of PT(lact), Pmax, and VO2max were made on 24 of the participants the same weeks MSSP was evaluated. After training, MSSP increased 9.2% (195.4 +/- 56.6 vs. 213.8 +/- 57.2 W; p < 0.05), and PT(lact) increased 12.9% (178.3 +/- 47.1 vs. 201.5 +/- 47.6 W; p < 0.05). The MSSP was approximately 7.5 % higher than PT(lact). Pmax increased approximately 6.7% (315.2 +/- 65.1 to 336.5 +/- 65.9 W), and VO2max increased approximately 6.5% (46.2 +/- 10.7 to 49.1 +/- 10.5 ml x kg(-1) x min(-1)). The MSSP and PT(lact) were highly correlated (r = 0.98) as was MSSP and VO2max (r = 0.90). The results of this research indicated that (a) the field test is a valid measure of fitness and changes in fitness, (b) it provided data for the establishment of training ranges, and (c) a biweekly power-based training program can elicit significant changes in fitness.