Interaction of exercise and meal timing on blood glucose concentrations.

PURPOSE OF REVIEW: Exercise and diet are among the most studied behaviors that can affect blood glucose concentrations. Despite multiple studies examining these interventions in different populations and contexts, inconsistencies across studies have led to variable expectations. The purpose of this review is to more specifically examine how the timing of when exercise is performed in relation to meals can modify changes in glucose concentrations or insulin sensitivity. When possible, studies in type 2 diabetes are emphasized, but recent research in type 1 diabetes, obesity, and athletes is also considered. RECENT FINDINGS: The effect of a single bout of exercise performed after an overnight fast is often comparable to that of postprandial exercise on 24 h mean glucose concentrations. However, there is recent evidence to suggest that in some situations, but not all, longer term metabolic adaptations can be more favorable when exercise is regularly performed in the fasted state. SUMMARY: Exercise after an overnight fast can have different effects on glucose metabolism compared with postprandial exercise. The shorter term and longer term changes following fasting exercise can be relevant to those who are seeking greater glucoregulatory benefit from their exercise sessions, such as people with diabetes.

A Randomized Trial of the Effects of Exercise on Anxiety, Fear of Cancer Progression and Quality of Life in Prostate Cancer Patients on Active Surveillance.

PURPOSE: We examined the effects of exercise on prostate cancer-specific anxiety, fear of cancer progression, quality of life and psychosocial outcomes in patients with prostate cancer on active surveillance. MATERIALS AND METHODS: The ERASE (Exercise during Active Surveillance for Prostate Cancer) Trial randomized 52 patients with prostate cancer undergoing active surveillance to high-intensity interval training (HIIT, 26 patients) or usual care (UC, 26 patients). The HIIT group performed a 12-week, thrice weekly, supervised, aerobic HIIT program. The UC group did not exercise. Patient-reported outcomes were assessed at baseline and after intervention, including prostate cancer-specific anxiety (Memorial Anxiety Scale for Prostate Cancer), fear of cancer progression (Fear of Cancer Recurrence Inventory), prostate cancer symptoms (Expanded Prostate Cancer Index Composite), quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core) and psychological health outcomes (eg fatigue, stress and self-esteem). Analysis of covariance was used to compare between-group differences. RESULTS: Fifty of 52 participants (96%) completed patient-reported outcome assessments at 12 weeks. Adherence to HIIT was 96%. Compared to UC, HIIT significantly improved total prostate cancer-specific anxiety (adjusted between-group mean difference -2.7, 95% confidence interval, range -5.0 to -0.4, p=0.024), as well as the fear of progression subscale (p=0.013), hormonal symptoms (p=0.005), perceived stress (p=0.037), fatigue (p=0.029) and self-esteem (p=0.007). CONCLUSIONS: A 12-week supervised HIIT program may improve prostate cancer-specific anxiety, fear of cancer progression, hormone symptoms, stress, fatigue and self-esteem in men with prostate cancer on active surveillance. Larger trials are needed to confirm the effects of HIIT on patient-reported outcomes in the active surveillance setting.

Effects of supervised high-intensity interval training on motivational outcomes in men with prostate cancer undergoing active surveillance: results from a randomized controlled trial.

BACKGROUND: Understanding the motivational effects of supervised aerobic high-intensity interval training (HIIT) may help men with prostate cancer undergoing active surveillance initiate and maintain exercise behavior, however, few studies have addressed this question. This report explored exercise motivation in men with prostate cancer undergoing active surveillance participating in a randomized exercise trial. METHODS: The Exercise during Active Surveillance for Prostate Cancer (ERASE) trial randomized 52 men with prostate cancer on active surveillance to the HIIT exercise group or the usual care (UC) group. The exercise program was supervised aerobic HIIT conducted three times per week for 12 weeks. The motivation questions were developed using the Theory of Planned Behavior and included motivational constructs, anticipated and experienced outcomes, and barriers to HIIT during active surveillance. RESULTS: The HIIT group attended 96% of the planned exercise sessions with 100% compliance to the exercise protocol. Motivation outcome data were obtained in 25/26 (96%) participants in the HIIT group and 25/26 (96%) participants in the UC group. At baseline, study participants were generally motivated to perform HIIT. After the intervention, the HIIT group reported that HIIT was even more enjoyable (p < 0.001; d = 1.38), more motivating (p = 0.001; d = 0.89), more controllable (p < 0.001; d = 0.85), and instilled more confidence (p = 0.004; d = 0.66) than they had anticipated. Moreover, compared to UC, HIIT participants reported significantly higher perceived control (p = 0.006; d = 0.68) and a more specific plan (p = 0.032; d = 0.67) for performing HIIT over the next 6 months. No significant differences were found in anticipated versus experienced outcomes. Exercise barriers were minimal, however, the most often reported barriers included pain or soreness (56%), traveling to the fitness center (40%), and being too busy and having limited time (36%). CONCLUSION: Men with prostate cancer on active surveillance were largely motivated and expected significant benefits from a supervised HIIT program. Moreover, the men assigned to the HIIT program experienced few barriers and achieved high adherence, which further improved their motivation. Future research is needed to understand long-term exercise motivation and behavior change in this setting. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03203460 . Registered on June 29, 2017.

A high-protein total diet replacement alters the regulation of food intake and energy homeostasis in healthy, normal-weight adults.

PURPOSE: Dietary intake can affect energy homeostasis and influence body weight control. The aim of this study was to compare the impact of high-protein total diet replacement (HP-TDR) versus a control (CON) diet in the regulation of food intake and energy homeostasis in healthy, normal-weight adults. METHODS: In this acute randomized controlled, cross-over study, participants completed two isocaloric arms: a) HP-TDR: 35% carbohydrate, 40% protein, and 25% fat; b) CON: 55% carbohydrate, 15% protein, and 30% fat. The diets were provided for 32 h while inside a whole-body calorimetry unit. Appetite sensations, appetite-related hormones, and energy metabolism were assessed. RESULTS: Forty-three healthy, normal-weight adults (19 females) participated. Appetite sensations did not differ between diets (all p > 0.05). Compared to the CON diet, the change in fasting blood markers during the HP-TDR intervention was smaller for peptide tyrosine-tyrosine (PYY; - 18.9 ± 7.9 pg/mL, p = 0.02) and greater for leptin (1859 ± 652 pg/mL, p = 0.007). Moreover, postprandial levels of glucagon-like peptide 1 (1.62 ± 0.36 pM, p < 0.001) and PYY (31.37 ± 8.05 pg/mL, p < 0.001) were higher in the HP-TDR. Significant correlations were observed between energy balance and satiety (r = - 0.41, p = 0.007), and energy balance and PFC (r = 0.33, p = 0.033) in the HP-TDR. CONCLUSION: Compared to the CON diet, the HP-TDR increased blood levels of anorexigenic hormones. Moreover, females and males responded differently to the intervention in terms of appetite sensations and appetite-related hormones. TRIAL REGISTRATION: NCT02811276 (retrospectively registered on 16 June 2016) and NCT03565510 (retrospectively registered on 11 June 2018).

Tiredness, Fatigue, and Exhaustion as Perceived by Recreational Marathon Runners.

In this article, we report the results of a study that was part of a five-study concept development project. Our goal was to learn about the nature of illness by exploring variations in the manifestations of fatigue, a symptom that is prevalent in both ill (cancer, depression, chronic fatigue syndrome) and selected nonill (recreational marathon runners, shift workers) populations. In this article, we report results of our study of recreational marathon runners, obtained from unstructured interviews with 13 runners between the ages 19 and 49 years using ethnoscience as the design. Key findings with implications for practice are the importance of planning recovery periods following large energy expenditures, the value of using dissociative strategies to manage tiredness, and the usefulness of associative strategies and support systems to manage fatigue. Future studies could explore whether these strategies would be useful for management of tiredness and fatigue in other populations.

Predictors of adherence to aerobic exercise in rectal cancer patients during and after neoadjuvant chemoradiotherapy.

This pilot study explored predictors of adherence to exercise during and after neoadjuvant chemoradiotherapy (NACRT) in rectal cancer patients. Eighteen rectal cancer patients were prescribed three supervised aerobic exercise sessions/week during NACRT followed by ≥150 min/week of unsupervised aerobic exercise after NACRT. Although not statistically significant, adherence to supervised exercise during NACRT was meaningfully better for patients who were women (d = .82; P = .12), younger (d = -.62; P = .30), married (d = .62; P = .42), with better mental health (r = .32; P = .21), fewer diarrhea symptoms (r = .48; P = .052), and higher anticipated enjoyment (r = .31; P = .23), support (r = .32; P = .22), and motivation (r = .31; P = .23). After NACRT, adherence was significantly better for patients who reported worse mental health (r = -.56; P = .046) and meaningfully better for patients who were women (d = .54; P = .38), better educated (d = .77; P = .22), had no comorbidities (d = -.63; P = .17), and exercised at baseline (d = 1.05; P = .12). Demographics, tumor side effects, and motivational variables may predict adherence to exercise during and after NACRT.

Exercise motivation in rectal cancer patients during and after neoadjuvant chemoradiotherapy.

PURPOSE: Aerobic exercise is safe and feasible for rectal cancer patients during and after neoadjuvant chemoradiotherapy (NACRT), but their motivation to perform such exercise is unknown. Here, we explore the motivational outcomes, perceived benefits and harms, and perceived barriers to exercise during and after NACRT. METHODS: Rectal cancer patients (n = 18) participated in supervised aerobic exercise during NACRT followed by unsupervised exercise after NACRT. Using the theory of planned behavior, we assessed perceived benefits, harms, enjoyment, support, difficulty, and barriers for exercise both during and after NACRT. RESULTS: Patients reported that exercise during NACRT was more enjoyable (p = 0.003) and less difficult (p = 0.037) than initially anticipated. The most common perceived benefits of exercise during NACRT were cardiovascular endurance (75 %), quality of life (75 %), and self-esteem (65 %). After NACRT, the most common perceived benefits were physical functioning (93 %), cardiovascular endurance (86 %), and quality of life (79 %). The most common perceived harms of exercise during NACRT were fatigue (31 %), diarrhea (31 %), and skin irritation (24 %). After NACRT, the most common perceived harms were fatigue (21 %) and hand-foot-syndrome (15 %). Side effects from NACRT were the most common exercise barrier during NACRT (88 %) whereas lack of motivation was the most common barrier after NACRT (79 %). CONCLUSIONS: Rectal cancer patients reported aerobic exercise during NACRT to be more enjoyable and less difficult than anticipated despite significant barriers. This positive motivational response may facilitate recruitment and adherence in future interventions. Moreover, rectal cancer patients identified potential benefits and harms that should be closely monitored in future interventions.

An Aerobic Cooldown After Morning, Fasted Resistance Exercise Has Limited Impact on Post-exercise Hyperglycemia in Adults With Type 1 Diabetes: A Randomized Crossover Study.

OBJECTIVES: Expert guidelines recommend an aerobic cooldown to lower blood glucose for the management of post-exercise hyperglycemia. This strategy has never been empirically tested. Our aim in this study was to compare the glycemic effects of performing an aerobic cooldown vs not performing a cooldown after a fasted resistance exercise session. We hypothesized that the cooldown would lower blood glucose in the 30 minutes after exercise and would result in less time in hyperglycemia in the 6 hours after exercise. METHODS: Participants completed 2 identical resistance exercise sessions. One was followed by a low-intensity (30% of peak oxygen consumption) 10-minute cycle ergometer cooldown, and the other was followed by 10 minutes of sitting. We compared the changes in capillary glucose concentration during these sessions and continuous glucose monitoring (CGM) outcomes over 24 hours post-exercise. RESULTS: Sixteen participants completed the trial. Capillary glucose was similar between conditions at the start of exercise (p=0.07). Capillary glucose concentration decreased by 0.6±1.0 mmol/L during the 10-minute cooldown, but it increased by 0.7±1.3 mmol/L during the same time in the no-cooldown condition. The resulting difference in glucose trajectory led to a significant interaction (p=0.02), with no effect from treatment (p=0.7). Capillary glucose values at the end of recovery were similar between conditions (p>0.05). There were no significant differences in CGM outcomes. CONCLUSIONS: An aerobic cooldown reduces glucose concentration in the post-exercise period, but the small and brief nature of this reduction makes this strategy unlikely to be an effective treatment for hyperglycemia occurring after fasted exercise.

Effects of high-intensity interval training on cardiometabolic biomarkers in patients with prostate cancer undergoing active surveillance: a randomized controlled trial.

PURPOSE: To report the effects of a 12-week high-intensity interval training (HIIT) program on cardiometabolic biomarkers in patients with prostate cancer on active surveillance (AS) from the Exercise During Active Surveillance for Prostate Cancer (ERASE) Trial. METHODS: Fifty-two men with prostate cancer on AS were randomized to either an exercise (HIIT; n = 26) or usual care (UC; n = 26) group. The HIIT intervention consisted of progressive, supervised, aerobic HIIT at an intensity of 85 to 95% VO2peak for 28 to 40 min per session performed three times/week for 12 weeks. Blood samples were collected at baseline and postintervention to analyze cardiometabolic biomarkers. Analysis of covariance was used to examine between-group mean differences. RESULTS: Blood data were obtained from 49/52 (94%) participants at postintervention. Participants were aged 63.4 ± 7.1 years and 40% were obese. The HIIT group attended 96% of the planned exercise sessions. No significant between-group changes in weight were observed after the intervention. Compared to UC, HIIT significantly improved total cholesterol (-0.40 mmol/L; 95% confidence interval[CI], -0.70 to -0.10; p = 0.011), non-high-density lipoprotein-c (-0.35 mmol/L; 95% CI, -0.60 to -0.11; p = 0.006), insulin (-13.6 pmol/L; 95% CI, -25.3 to -1.8; p = 0.025), insulin-like growth factor (IGF)-1 (-15.0 ng/mL; 95% CI, -29.9 to -0.1; p = 0.048), and IGF binding protein (IGFBP)-3 (152.3 ng/mL; 95% CI, 12.6 to 292.1; p = 0.033). No significant differences were observed for fasting glucose, HbA1c, other lipid markers, IGFBP-1, adiponectin, and leptin. CONCLUSIONS: The ERASE Trial showed that a 12-week aerobic HIIT program improved several cardiometabolic biomarkers in patients with prostate cancer on AS that may contribute to cardiovascular health benefits and potentially influence signaling pathways in the progression of prostate cancer. Further research is needed to confirm the effects of exercise on cardiometabolic markers in men with prostate cancer on AS and determine if these effects are associated with improved long-term clinical outcomes.

Blood Glucose During High Altitude Trekking in Young Healthy Adults.

Reid, Ly-Anh, Jordan L Rees, Miranda Kimber, Marina James, Graeme M Purdy, Megan Smorschok, Lauren E Maier, Normand G. Boulé, Trevor A. Day, Margie H. Davenport, and Craig D. Steinback. Blood glucose during high altitude trekking in young healthy adults. High Alt Med Biol. 00:00-00, 2024. Introduction: High altitude trekking is becoming more popular and accessible to an increased number of people. Simultaneously, there is a worldwide rise in the prevalence of metabolic diseases. The purpose of this study was to examine the impact of a gradual trekking ascent to high altitude on continuous glucose monitoring outcomes including fasting, mean 24-hour, postprandial, and post-75 g modified oral glucose tolerance test. This study also investigated the relationship between physical activity intensity, high altitude, and glucose concentrations. Methods: Individuals (n = 9) from Alberta, Canada participated in a 2-week trek in the Khumbu Valley in Nepal, ascending by foot from 2,860 m to 5,300 m (∼65 km) over 10 days. A standardized 75 g oral glucose load was given to participants at four different altitudes (1,130 m, 3,440 m, 3,820 m, 5,160 m). Physical activity (Actigraph accelerometry) and interstitial glucose (iPro2, Medtronic) were measured continuously during the trek. Results: Fasting and mean 24-hour glucose concentrations were not different between altitudes. However, 2-hour post dinner glucose and 2-hour post lunch glucose, AUC concentrations were different between altitudes. The relationship between physical activity intensity and glucose was not influenced by increasing altitudes. Conclusion: Our findings suggest that glucose regulation is largely preserved at high altitude; however, inconsistency in our postprandial glucose concentrations at altitude warrants further investigation.

Does metformin modify the effect on glycaemic control of aerobic exercise, resistance exercise or both?

AIMS/HYPOTHESIS: Some previous studies suggested that metformin might attenuate the effects of exercise on glycaemia or fitness. We therefore examined whether metformin use influenced changes in glycaemic control, fitness, body weight or waist circumference resulting from aerobic and/or resistance training in people with type 2 diabetes participating in an exercise intervention trial. METHODS: After a 4 week run-in period, participants from the Diabetes Aerobic and Resistance Exercise (DARE) trial were randomly assigned to 22 weeks of aerobic training alone, resistance training alone, combined aerobic and resistance exercise training or a waiting-list control group. Of the 251 randomised, 143 participants reported using metformin throughout the entire study period and 82 reported not using metformin at all. RESULTS: Compared with control, aerobic training led to a significant reduction in HbA1c in the metformin users (-0.57%, 95% CI -1.05, -0.10; -6.3 mmol/mol, 95% CI -11.5, -1.1) but not in the non-metformin users (-0.17, 95% CI -0.78, 0.43; -1.9 mmol/mol, 95% CI -8.5, 4.7). However, there were no significant differences in the changes in HbA1c (or fasting glucose) between metformin users and non-users in any of the exercise groups compared with control (p> 0.32 for all metformin by group by time interactions). Similarly, metformin did not affect changes in indicators of aerobic fitness, strength and body weight or waist circumference (p ≥ 0.15 for all metformin by group by time interactions). CONCLUSIONS/INTERPRETATION: Contrary to our hypothesis and to previous short-term studies, metformin did not significantly attenuate the benefits of exercise on glycaemic control or fitness.

The Effect of Starting Blood Glucose Levels on Serum Electrolyte Concentrations during and after Exercise in Type 1 Diabetes.

Fear of hypoglycemia is a major exercise barrier for people with type 1 diabetes (PWT1D). Consequently, although guidelines recommend starting exercise with blood glucose (BG) concentration at 7-10 mmol/L, PWT1D often start higher, potentially affecting hydration and serum electrolyte concentrations. To test this, we examined serum and urine electrolyte concentrations during aerobic exercise (cycling 45 min at 60%VO2peak) in 12 PWT1D (10F/2M, mean ± SEM: age 29 ± 2.3 years, VO2peak 37.9 ± 2.2 mL·kg-1·min-1) with starting BG levels: 8-10 (MOD), and 12-14 (HI) mmol/L. Age, sex, and fitness-matched controls without diabetes (CON) completed one exercise session with BG in the normal physiological range. Serum glucose was significantly higher during exercise and recovery in HI versus MOD (p = 0.0002 and p < 0.0001, respectively) and in MOD versus CON (p < 0.0001). During exercise and recovery, MOD and HI were not significantly different in serum insulin (p = 0.59 and p = 0.63), sodium (p = 0.058 and p = 0.08), potassium (p = 0.17 and p = 0.16), calcium (p = 0.75 and 0.19), and magnesium p = 0.24 and p = 0.09). Our findings suggest that exercise of moderate intensity and duration with higher BG levels may not pose an immediate risk to hydration or serum electrolyte concentrations for PWT1D.

Effects of exercise during and after neoadjuvant chemoradiation on symptom burden and quality of life in rectal cancer patients: a phase II randomized controlled trial.

PURPOSE: We previously demonstrated that exercise during and after neoadjuvant chemoradiation (NACRT) for rectal cancer may improve the rate of pathologic complete/near complete response. Here, we report the effects of exercise on symptom management and quality of life (QoL). METHODS: Rectal cancer patients (N = 36) were randomized to a supervised high-intensity interval training program during NACRT followed by unsupervised continuous exercise after NACRT or usual care. Patient-reported outcomes were assessed at baseline, post-NACRT, and presurgery including symptom burden (M.D. Anderson Symptom Inventory) and QoL (European Organisation for Research and Treatment of Cancer QLQ- C30 and -CR29). RESULTS: During NACRT, exercise significantly worsened stool frequency (adjusted between-group difference, 25.8; 95% CI, 4.0 to 47.6; p = 0.022), role functioning (adjusted between-group difference, -21.3; 95% CI, -41.5 to -1.1; p = 0.039), emotional functioning (adjusted between-group difference, -11.7; 95% CI, -22.0 to -1.4; p = 0.028), and cognitive functioning (adjusted between-group difference, -11.6; 95% CI, -19.2 to -4.0; p = 0.004) compared to usual care. After NACRT, exercise significantly worsened diarrhea (adjusted between-group difference, 1.2; 95% CI, 0.1 to 2.3; p = 0.030) and embarrassment (adjusted between-group difference, 19.7; 95% CI, 7.4 to 32.1; p = 0.003) compared to usual care. CONCLUSIONS: Exercise exacerbated some symptoms and worsened QoL during NACRT; however, most negative effects dissipated after NACRT. Larger trials are necessary to confirm these findings. IMPLICATIONS FOR CANCER SURVIVORS: If the clinical benefit of exercise is confirmed, then the modest symptom exacerbation during NACRT may be considered tolerable. However, in the absence of any clinical benefit, exercise may be contraindicated in this clinical setting.

Systematic Review and Meta-analysis of Blood Glucose Response to High-intensity Interval Exercise in Adults With Type 1 Diabetes.

OBJECTIVES: Exercise-induced hyperglycemia is recognized in type 1 diabetes (T1D) clinical guidelines, but its association with high-intensity intermittent exercise (HIIE) in acute studies is inconsistent. In this meta-analysis, we examined the available evidence of blood glucose responses to HIIE in adults with T1D. The secondary, aim was to examine predictors of blood glucose responses to HIIE. We hypothesized that there would be no consistent effect on blood glucose from HIIE, unless examined in the context of participant prandial status. METHODS: We conducted a literature search using key words related to T1D and HIIE. Studies were required to include at least 6 participants with T1D with a mean age >18 years, involve an HIIE intervention, and contain pre- and postexercise measures of blood glucose. Analyses of extracted data were performed using a general inverse variance statistical method with a random effects model and a weighted multiple regression. RESULTS: Nineteen interventions from 15 reports were included in the analysis. A mean overall blood glucose decrease of -1.3 mmol/L (95% confidence interval [CI], -2.3 to -0.2 mmol/L) was found during exercise, albeit with high heterogeneity (I2=84%). When performed after an overnight fast, exercise increased blood glucose by +1.7 mmol/L (95% CI, 0.4 to 3.0 mmol/L), whereas postprandial exercise decreased blood glucose by -2.1 mmol/L (95% CI, -2.8 to -1.4 mmol/L), with a statistically significant difference between groups (p<0.0001). No associations with fitness (p=0.4), sex (p=0.4), age (p=0.9), exercise duration (p=0.9), or interval duration (p=0.2) were found. CONCLUSION: The effect of HIIE on blood glucose is inconsistent, but partially explained by prandial status.

Effects of Exercise on Motivational Outcomes in Rectal Cancer Patients During and After Neoadjuvant Chemoradiation: A Phase II Randomized Controlled Trial.

OBJECTIVES: Understanding exercise motivation in rectal cancer patients during and after neoadjuvant chemoradiation therapy is important to improve adherence and achieve potential benefit. We report the motivational effects of exercise from the Exercise During and After Neoadjuvant Rectal Cancer Treatment trial. DATA SOURCES: We randomized 36 rectal cancer patients to supervised high-intensity interval training during neoadjuvant chemoradiation therapy followed by unsupervised moderate-to-vigorous exercise after therapy, or usual care. Using the theory of planned behavior, we assessed motivation, perceived benefits/harms, and perceived barriers for exercise during and after therapy. Supervised exercise during neoadjuvant chemoradiation therapy was experienced as meaningfully (d≥0.33) more controllable (p=0.08, d=0.60), more enjoyable (p=0.25, d=0.45), and less difficult (p=0.45, d=-0.38) than anticipated. Unsupervised exercise after therapy was experienced as meaningfully more enjoyable (p=0.047, d=0.50) and less difficult (p=0.43, d=-0.36), but also less controllable (p=0.14, d=-0.80) than anticipated. Common self-reported benefits of exercise both during and after neoadjuvant chemoradiation therapy were cardiovascular endurance, physical functioning, and quality of life. Common self-reported harms were exacerbation of treatment side effects. Frequently reported barriers to exercise during therapy were side effects of treatment, whereas exercise barriers after therapy were lack of motivation and lingering side effects. CONCLUSION: Exercise during and after therapy generally had positive effects on exercise motivation, however, perceived harms and barriers related to treatment side effects were identified. IMPLICATIONS FOR NURSING PRACTICE: Nurses can help rectal cancer patients initiate and maintain exercise during and after neoadjuvant chemoradiation by discussing the potential benefits, harms, and barriers to exercise.

Cost-effectiveness of exercise programs in type 2 diabetes.

BACKGROUND: A randomized controlled trial has shown that supervised, facility-based exercise training is effective in improving glycemic control in type 2 diabetes. However, these programs are associated with additional costs. This analysis assessed the cost-effectiveness of such programs. METHODS: Analysis used data from the Diabetes Aerobic and Resistance Exercise (DARE) clinical trial which compared three different exercise programs (resistance, aerobic or a combination of both) of 6 months duration with a control group (no exercise program). Clinical outcomes at 6 months were entered for individual patients into the UKPDS economic model for type 2 diabetes adapted for the Canadian context. From this, expected life-years, quality-adjusted life-years (QALYs) and costs were estimated for all patients within the trial. RESULTS: The combined exercise program was the most expensive ($40,050) followed by the aerobic program ($39,250), the resistance program ($38,300) and no program ($31,075). QALYs were highest for combined (8.94), followed by aerobic (8.77), resistance (8.73) and no program (8.70). The incremental cost per QALY gained for the combined exercise program was $4,792 compared with aerobic alone, $8,570 compared with resistance alone, and $37,872 compared with no program. The combined exercise program remained cost-effective for all scenarios considered within sensitivity analysis. CONCLUSIONS: A program providing training in both resistance and aerobic exercise was the most cost-effective of the alternatives compared. Based on previous funding decisions, exercise training for individuals with diabetes can be considered an efficient use of resources.

Associations between body mass index and bladder cancer survival: Is the obesity paradox short-lived?

INTRODUCTION: We investigated the associations of pre-surgical body mass index (BMI) with bladder cancer outcomes in patients treated with radical cystectomy. METHODS: We retrospectively analyzed data from 488 bladder cancer patients treated with radical cystectomy between 1994 and 2007 and followed up until 2016. Cox regression with step function (time-segment analysis) was conducted for overall survival because the proportional hazard assumption was violated. RESULTS: Of 488 bladder cancer patients, 155 (31.8%) were normal weight, 186 (38.1%) were overweight, and 147 (30.1%) were obese. During the median followup of 59.5 months, 363 (74.4%) patients died, including 197 (40.4%) from bladder cancer. In adjusted Cox regression analyses, BMI was not significantly associated with bladder cancer-specific survival for overweight (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.57-1.10, p=0.16) or obese (HR 0.76, 95% CI 0.52-1.09, p=0.13) patients. In the Cox regression with step function for overall survival, the time interaction was significant overall (p=0.020) and specifically for over-weight patients (p=0.006). In the time-segment model, the HR for overweight during the first 63 months was 0.66 (95% CI 0.49-0.90, p=0.008), whereas it was 1.41 (95% CI 0.89-2.23, p=0.14) after 63 months. Although not statistically significant, a similar pattern was observed for obese patients. CONCLUSIONS: Our findings suggest that overweight and obese bladder cancer patients had better outcomes within the first five years after radical cystectomy; however, there were no differences in longer-term survival. These data suggest that the obesity paradox in bladder cancer patients treated with radical cystectomy may be short-lived.

Bladder cancer and exeRcise trAining during intraVesical thErapy-the BRAVE trial: a study protocol for a prospective, single-centre, phase II randomised controlled trial.

INTRODUCTION: Non-muscle invasive bladder cancer (NMIBC) accounts for about 75% of newly diagnosed bladder cancers. The treatment for NMIBC involves surgical removal of the tumour followed by 6 weekly instillations of immunotherapy or chemotherapy directly into the bladder (ie, intravesical therapy). NMIBC has a high rate of recurrence (31%-78%) and progression (15%). Moreover, bladder cancer and its treatment may affect patient functioning and quality of life. Exercise is a safe and effective intervention for many patient with cancer groups, however, no studies have examined exercise during intravesical therapy for NMIBC. The primary objective of the Bladder cancer and exeRcise trAining during intraVesical thErapy (BRAVE) trial is to examine the safety and feasibility of an exercise intervention in patients with bladder cancer undergoing intravesical therapy. The secondary objectives are to investigate the preliminary efficacy of exercise on health-related fitness and patient-reported outcomes; examine the social cognitive predictors of exercise adherence; and explore the potential effects of exercise on tumour recurrence and progression. METHODS AND ANALYSIS: BRAVE is a phase II randomised controlled trial that aims to include 66 patients with NMIBC scheduled to receive intravesical therapy. Participants will be randomly assigned to the exercise intervention or usual care. The intervention consists of three supervised, high-intensity interval training sessions per week for 12 weeks. Feasibility will be evaluated by eligibility, recruitment, adherence and attrition rates. Preliminary efficacy will focus on changes in cardiorespiratory fitness and patient-reported outcomes from baseline (prior to intravesical therapy) to pre-cystoscopy (3 months). Cancer outcomes will be tracked at 3 months, and 1-year follow-up by cystoscopy. Analysis of covariance will compare between-group differences at post-intervention (pre-cystoscopy) for all health-related fitness and patient-reported outcomes. ETHICS AND DISSEMINATION: The study was approved by the Health Research Ethics Board of Alberta-Cancer Committee (#20-0184). Dissemination will include publication and presentations at scientific conferences and public channels. TRIAL REGISTRATION NUMBER: NCT04593862; Pre-results.