Year-long Exercise Intervention Research Articles

The Impact of Multimorbidity Patterns on Changes in Physical Activity and Physical Capacity Among Older Adults Participating in a Year-Long Exercise Intervention.

This study investigated the impact of multimorbidity patterns on physical activity and capacity outcomes over the course of a year-long exercise intervention, and on physical activity 1year later. Participants were 314 physically inactive community-dwelling men and women aged 70-85years, with no contraindications for exercise at baseline. Physical activity was self-reported. Physical capacity measurements included five-time chair-stand time, 6-minute walking distance, and maximal isometric knee-extension strength. The intervention included supervised and home-based strength, balance, and walking exercises. Multimorbidity patterns comprised physician-diagnosed chronic disease conditions as a predictor cluster and body mass index as a measure of obesity. Multimorbidity patterns explained 0%-12% of baseline variance and 0%-3% of the change in outcomes. The magnitude and direction of the impact of unique conditions varied by outcome, time point, and sex. Multimorbid older adults with no contraindications for exercise may benefit from multimodal physical training.

The impact of exercise on growth factors (VEGF and FGF2): results from a 12-month randomized intervention trial

BackgroundVascular endothelial growth factor (VEGF) and Fibroblast growth factor-2 (FGF2) are angiogenic cytokines in normal tissues and tumors. Evidence suggests that increased growth factor expression in adipose tissue leads to improved vascularity and decreased hypoxia, fibrosis, and inflammation, which may, in turn, reduce post-menopausal breast cancer risk.ObjectiveWe investigated whether or not exercise had dose-response effects on levels of plasma VEGF and FGF2 in postmenopausal women.MethodsFour hundred previously inactive but healthy postmenopausal women aged 50–74 years of age were randomized to 150 or 300 min per week of aerobic exercise in a year-long exercise intervention. VEGF and FGF2 were measured from fasting serum samples with a custom-plex multiplex assay.ResultsA high compared to moderate volume of aerobic exercise did not cause chronic changes in plasma VEGF or FGF2 levels in intention-to-treat or per-protocol analyses.ConclusionsWe did not detect differences in growth factor levels related to increasing doses of exercise. It is unlikely that changes in VEGF and FGF2 levels mediate the reduction in risk of post-menopausal breast cancer development in associated with increased levels of exercise.Trial registrationClinicaltrials.gov identifier: NCT01435005.

Exercise Dose Effects on Body Fat 12 Months after an Exercise Intervention: Follow-up from a Randomized Controlled Trial.

Background Exercise interventions can result in weight loss, which is associated with reductions in disease risk. It is unknown how the volume of exercise prescribed in a one-time exercise intervention impacts long-term body fatness. We compared 24-month body fat changes among postmenopausal women previously prescribed 300 versus 150 minutes/week of exercise in a year-long exercise intervention trial. Methods The Breast Cancer and Exercise Trial in Alberta (BETA) was a two-centred randomized controlled trial in Alberta, Canada. The trial consisted of a 12-month intervention and 12-month observation period. For the intervention, participants were randomized to either a moderate-volume exercise group (150 min/week) or a high-volume exercise group (300 min/week). Participants in this study were 334 inactive postmenopausal women who had been followed-up to 24 months. The primary outcome for this study was 24-month change in total body fat using dual energy X-ray absorptiometry scans. Other measures included weight, waist and hip circumferences, subcutaneous and intra-abdominal fat from computed tomography scans, and lean mass. Researchers were blinded to randomization group when measuring body fat. Results Both groups self-reported ∼180 minutes/week moderate–vigorous activity at 24 months. No statistically significant difference was found in total body fat at 24 months between the two groups. Statistically significant effects (comparing high versus moderate groups) were found for BMI (least-square mean change (95% CI): −0.66 (−0.97, −0.36) versus −0.25 (−0.55, 0.05) kg/m2, P=0.04), waist-to-hip ratio (−0.033 (−0.040, −0.026) versus −0.023 (−0.030, −0.016), P=0.05), and subcutaneous abdominal fat area (−32.18 (−39.30, −25.06) versus −22.20 (−29.34, −15.05) cm2, P=0.04). Conclusion Prescribing 300 versus 150 minutes/week of exercise to inactive postmenopausal women resulted in some long-term greater decreases in measures of body composition but no overall differences in total body fat loss. This trail is registered with NCT01435005.

Objective Measurement of Physical Activity in Adults With Newly Diagnosed Type 1 Diabetes and Healthy Individuals.

Aims: Physical activity (PA) has many benefits in type 1 diabetes mellitus (type 1 DM). However, PA levels in people with type 1 DM have not previously been measured accurately. We aimed to compare objectively measured PA in adults recently diagnosed with type 1 DM and healthy adults.Methods: Accelerometer data from 65 healthy adults [mean (SD) age 31 (13), 29% men] were compared with data from 50 people with type 1 DM [mean (SD) age 33 (10), 64% men], time since diagnosis <3months, HbA1c 76 ± 25 mmol/mol) in the EXTOD (Exercise for Type 1 Diabetes) pilot study. Briefly, EXTOD investigated the feasibility of recruiting recently diagnosed adults with type 1 DM into a yearlong exercise intervention. Multiple-regression models were used to investigate the association between diabetes status and activity outcomes.Results: Adults recently diagnosed with type 1 DM spent on average a quarter less time in moderate-to-vigorous-physical-activity (MVPA) per day than healthy adults [after adjusting for confounders, predicted values: type 1 DM adults: [mean (SD)] 37.4 mins/day (9.1) Healthy adults: 52.9 mins/day (11.0)]. No difference in MVPA between the groups was seen at the weekend, but adults with type 1 DM spent more time in light physical activity (LPA), and less time in sedentary behavior. Time spent in sedentary or LPA during weekdays did not differ between groups.Summary: Adults recently diagnosed with type 1 DM do less MVPA. Health care workers should encourage these people to engage in more PA. Further studies are needed to assess PA in people with type 1 DM of longer duration.

Effects of exercise on markers of oxidative stress: an Ancillary analysis of the Alberta Physical Activity and Breast Cancer Prevention Trial

BackgroundOxidative stress may contribute to cancer aetiology through several mechanisms involving damage to DNA, proteins and lipids leading to genetic mutations and genomic instability. The objective of this study was...

Physical Exercise Training versus Relaxation in Allogeneic stem cell transplantation (PETRA Study) – Rationale and design of a randomized trial to evaluate a yearlong exercise intervention on overall survival and side-effects after allogeneic stem cell transplantation

BackgroundAllogeneic stem cell transplantation (allo-HCT) is associated with high treatment-related mortality and innumerable physical and psychosocial complications and side-effects, such as high fatigue levels, loss of physical performance, infections, graft-versus-host disease (GvHD) and distress. This leads to a reduced quality of life, not only during and after transplantation, but also in the long term. Exercise interventions have been shown to be beneficial in allo-HCT patients. However, to date, no study has focused on long-term effects and survival. Previous exercise studies used ‘usual care’ control groups, leaving it unclear to what extent the observed effects are based on the physical effects of exercise itself, or rather on psychosocial factors such as personal attention. Furthermore, effects of exercise on and severity of GvHD have not been examined so far. We therefore aim to investigate the effects and biological mechanisms of exercise on side-effects, complications and survival in allo-HCT patients during and after transplantation.Methods/designThe PETRA study is a randomized, controlled intervention trial investigating the effects of a yearlong partly supervised mixed exercise intervention (endurance and resistance exercises, 3–5 times per week) in 256 patients during and after allogeneic stem cell transplantation. Patients in the control group perform progressive muscle relaxation training (Jacobsen method) with the same frequency. Main inclusion criterion is planned allo-HCT. Main exclusion criteria are increased fracture risk, no walking capability or severe cardiorespiratory problems. Primary endpoint is overall survival after two years; secondary endpoints are non-relapse mortality, median survival, patient reported outcomes including cancer related fatigue and quality of life, physical performance, body composition, haematological/immunological reconstitution, inflammatory parameters, severity of complications and side-effects (e.g. GvHD and infections), and cognitive capacity.DiscussionThe PETRA study will contribute to a better understanding of the physiological and psychological effects of exercise training and their biological mechanisms in cancer patients after allo-HCT. The ultimate goal is the implementation of optimized intervention programs to reduce side-effects and improve quality of life and potentially prognosis after allogeneic stem cell transplantation.Trial registrationClinicalTrials.gov Identifier: NCT01374399.

Predicting Adherence of Adults to a 12-Month Exercise Intervention

The purpose of this study was to (a) examine demographic, psychosocial, and physiological predictors of exercise adherence in a yearlong exercise intervention and (b) describe the trajectory of adherence over time. Participants were 51 men and 49 women aged 40 to 75 years. The supervised and home-based intervention consisted of 60 minutes/day, 6 days/ week of moderate-to-vigorous intensity exercise. Three adherence measures were used: (1) minutes/week, (2) MET-hours/week, and (3) change in cardiopulmonary fitness (VO2max). Predictors of adherence were determined separately by sex using mixed models and multivariable regression. Participants performed 287 ± 98 minutes/week of moderate-to-vigorous activity with 71% adhering to at least 80% (288 minutes/week) of the prescription. Men adhered better than women (P < .001). Among women, adiposity-related variables were significantly related to poorer adherence on all 3 measures (P < .05). A less consistent pattern was observed among men but in follow-up analyses, adiposity was associated with fewer MET-hours/week of exercise. Social support, pain, and perceived benefits were predictive in some models. Men and nonobese women experienced peak adherence at 4 to 6 months, while obese women peaked during months 0 to 3. When provided with supervision and support, previously sedentary men and women can achieve and maintain high levels of aerobic activity.

Aromatase inhibitors, arthralgias, and exercise in breast cancer survivors.

TPS669 Background: A substantial number of breast cancer survivors who are taking aromatase inhibitors (AIs) complain of side effects including arthralgias. Given the efficacy of AIs, it is essential that we identify approaches to mitigate arthralgias. We are conducting an NCI-funded trial is to examine the impact of a year-long exercise intervention in 180 breast cancer survivors taking an AI and experiencing at least mild arthralgias. Outcomes include severity of arthralgias, endocrine-related quality of life, % body fat, bone mass, and serum markers of inflammation. The purpose of this abstract is to present preliminary recruitment and adherence results. Methods: Women are being recruited via the Connecticut Tumor Registry and Rapid Case Ascertainment Shared Resource of Yale Cancer Center into the Hormones and Physical Exercise (HOPE) Study. Participants are randomly assigned to exercise (n = 90) or usual care (n = 90). The exercise intervention includes supervised resistance and unsupervised aerobic exercise sessions over 12 months. Data are collected at baseline, 3-, 6-, 9 and 12-months. Results: Study recruitment began in April 2010 and will continue through December 2012. As of January 1, 2012, we have received 1605 names of potentially eligible women. Of these 1605, 777 women are waiting to be screened (e.g., letter mailed to patient or on hold because recently diagnosed), 244 women could not be screened (e.g., unable to contact by phone), and 584 women have completed a telephone screening. Of the 584 women screened, 24% were ineligible because of discontinuing AIs because of arthralgias or chose not to take AIs primarily because of this potential side effect; another 36% were ineligible for various reasons; 24% were not interested; 11% were randomized (n = 65 women); and 5% are undergoing baseline visits (n = 29). On average, women are 62 yrs old and have been taking an AI for 1.8 yrs. Twenty-three women have completed the trial, with high exercise adherence rates (attendance to supervised sessions = 82% ). Conclusions: A growing number of women are choosing to not take AIs or are discontinuing AIs because of side effects. Our study may prove beneficial for the growing number of women diagnosed with hormone receptor-positive breast cancer each year.

Mediators and moderators of the effects of a year-long exercise intervention on endogenous sex hormones in postmenopausal women

ObjectiveTo identify factors that mediate or moderate the effects of exercise on postmenopausal sex hormone concentrations.MethodsPostmenopausal women were randomized to 12 months of aerobic exercise for 200 min/week (n = 160) or to a control group (n = 160). Intention-to-treat analyses were performed using general linear models with sex hormone concentrations at 6 and 12 months as the outcome. Mediation by adiposity and insulin was investigated by examining changes in effect estimates after adjustment for changes in these factors over 12 months. Moderation was studied as the interaction between group assignment and eight baseline characteristics.ResultsIntervention effects on sex hormone–binding globulin (SHBG) and estradiol changes were attenuated with adjustment for change in overall body fat, while there was less attenuation adjusting for intra-abdominal fat change. Intervention effects on SHBG levels were unaffected by adjustment for insulin change. Significant interactions were identified between treatment and physical fitness (for SHBG and testosterone) and age (for testosterone), implying subgroup differences in intervention effect.ConclusionsOur data suggest that overall fat loss partially mediated exercise-induced changes in estradiol and SHBG concentrations. No previous RCT in postmenopausal women has studied moderators of exercise-induced sex hormone changes; therefore, future studies are needed to corroborate our results.

Abstract PL03-04: Exercise, adiposity, and cancer

Abstract PL03-04: Exercise, adiposity, and cancer

Effect of Exercise on Oxidative Stress

This study examined the effect of a yearlong exercise intervention on F2-isoprostane, a specific marker of lipid peroxidation and a general marker of oxidative stress. In a randomized, controlled trial, 173 overweight or obese, postmenopausal, sedentary women were randomized either to an aerobic exercise intervention (60%-75% observed maximal HR) for > or =45 min.d-1, 5 d.wk-1 (n = 87), or to a stretching control group (n = 86), on an intent-to-treat basis. Baseline and 12-month measures included urinary F2-isoprostane, maximal O2 uptake, body weight, body fat percentage, waist circumference, and intra-abdominal fat surface area. Urine samples were available from 172 and 168 women at baseline and 12 months, respectively. During the 12-month study, controls minimally changed maximal O2 uptake (+0.2%) and body weight (+0.1 kg), whereas exercisers increased maximal O2 uptake (+13.6%; P < 0.0001 vs controls) and decreased body weight (-1.3 kg; P = 0.007 vs controls). F2-isoprostane increased slightly among controls (+3.3%) and decreased in exercisers (-6.2%), although the effect was not statistically significant (P = 0.26). In planned subgroup analyses, F2-isoprostane decreased linearly with gain in maximal O2 uptake (Ptrend = 0.005) relative to controls; exercisers who increased maximal O2 uptake by >15% decreased F2-isoprostane by 14.1% (P = 0.005 vs controls). A borderline statistically significant trend was observed between decreased waist circumference and F2-isoprostane (P = 0.06). Similar subgroup analyses by 12-month changes in body fat percentage, weight, and intra-abdominal fat were not statistically significant. These findings suggest that aerobic exercise, when accompanied by relatively marked gains in aerobic fitness, decreases oxidative stress among previously sedentary older women and that these effects occur with minimal change in mass or body composition.

Alberta physical activity and breast cancer prevention trial: sex hormone changes in a year-long exercise intervention among postmenopausal women.

We examined how an aerobic exercise intervention influenced circulating estradiol, estrone, sex hormone-binding globulin (SHBG), androstenedione, and testosterone levels, which may be involved in the association between physical activity and breast cancer risk. A two-center, two-arm randomized controlled trial of exercise was conducted in 320 postmenopausal, sedentary women age 50 to 74 years. Participants were randomly assigned to a 1-year aerobic exercise intervention of 225 min/wk (n = 160) or to a control group who maintained their usual level of activity (n = 160). Baseline, 6-month, and 12-month assessments of estrone, estradiol, androstenedione, and testosterone were quantified by radioimmunoassay after extraction, and SHBG was quantified by an immunometric assay. Intent-to-treat analyses were performed using linear mixed models. Blood data were available on 309 women (96.6%) at 12 months. Women in the intervention group exercised an average of 3.6 d/wk for 178 min/wk. At 12 months, statistically significant reductions in estradiol (treatment effect ratio [TER] = 0.93; 95% CI, 0.88 to 0.98) and free estradiol (TER = 0.91; 95% CI, 0.87 to 0.96) and increases in SHBG (TER = 1.04; 95% CI, 1.02 to 1.07) were observed in the exercise group compared with the control group. No significant differences in estrone, androstenedione, and testosterone levels were observed between exercisers and controls at 12 months. This trial found that previously sedentary postmenopausal women can adhere to a moderate- to vigorous-intensity exercise program that results in changes in estradiol and SHBG concentrations that are consistent with a lower risk for postmenopausal breast cancer.

A Yearlong Exercise Intervention Decreases CRP among Obese Postmenopausal Women

To investigate the effect of a yearlong moderate-intensity aerobic exercise intervention on C-reactive protein (CRP), serum amyloid A (SAA), and interleukin 6 (IL-6) among overweight or obese postmenopausal women. In a randomized controlled trial, 115 postmenopausal, overweight or obese, sedentary women, aged 50-75 yr were randomized to an aerobic exercise intervention of moderate-intensity (60%-75% observed maximal HR), for > or = 45 min x d(-1), 5 d x wk (n = 53), or to a 1-d x wk(-1) stretching control (n = 62), on an intent-to-treat basis. CRP, SAA, and IL-6 were measured at baseline, at 3 months, and at 12 months. From baseline to 12 months, CRP decreased 10% in exercisers and increased 12% in controls (P = 0.01); no effects were observed for SAA and IL-6. Among participants at baseline who were obese (body mass index (BMI) > or = 30 kg x m(-2)) or had abdominal obesity (waist circumference (WC) > or = 88 cm), exercise resulted in a more pronounced reduction in CRP (BMI > or = 30 kg x m(-2), P = 0.002; WC > or = 88 cm, P < 0.0001), borderline for SAA (BMI > or = 30 kg x m(-2), P = 0.08; WC > or = 88 cm, P = 0.04); no intervention effects were observed among women who did not have these characteristics. Overall, weight loss was minimal in the exercise intervention ( approximately 1.8 kg). Linear trends were observed between CRP and 12-month changes in aerobic fitness (Ptrend = 0.006), exercise adherence (Ptrend = 0.004), percentage body fat (Ptrend = 0.002), body weight (Ptrend = 0.002), WC (Ptrend = 0.02), and intra-abdominal fat (Ptrend = 0.03). A moderate-intensity exercise intervention reduced CRP for 12 months among women who were obese at baseline. These findings support the role of exercise in modulating inflammatory processes that are related to increased risk of chronic disease among obese women.

Effects of an exercise intervention on other health behaviors in overweight/obese post-menopausal women

Background Little is known about whether initiating physical activity induces change in other health-related behaviors. If other behaviors do change with increasing physical activity, this would complicate interpretation of differences in study outcomes in exercise intervention trials. Design Randomized controlled trial. Setting/participants 173 sedentary, overweight (body mass index between 24.0 and 25.0 kg/m 2 with body fat > 33% or BMI ≥ 25.0 kg/m 2), postmenopausal women, ages 50 to 75 years, not using hormone therapy, and living in the Seattle, WA area. Intervention Participants were randomly assigned to an exercise intervention ( n = 87) or a stretching-control group ( n = 86). The exercise intervention included facility and home-based moderate-intensity exercise. Main outcome measures Changes in dietary intake, alcohol consumption, and medication and supplement use were compared from baseline to 3- and 12-month follow-up between exercise and control groups, and by tertiles of exercise adherence. Data were collected between January 1998 and July 2001. Results In general, changes in dietary intake between the exercise and control group were not statistically different. The exercise group had a greater increase in the proportion of participants who used multivitamins (+ 5%) compared to the control group (− 10%) at 3 months ( p-interaction = 0.04), but not at 12 months ( p-interaction = 0.58). Furthermore, there were few differences when comparing changes in health behaviors across exercise adherence tertiles. Conclusions Our results suggest that participation in a year-long exercise intervention trial among post-menopausal women has little effect on other health behaviors. These findings suggest that additional behavior changes in exercise trials are minimal and unlikely to bias primary study results.

Influence of demographic, physiologic, and psychosocial variables on adherence to a yearlong moderate-intensity exercise trial in postmenopausal women

Background. Few studies have examined the long-term adherence to a yearlong exercise intervention among postmenopausal women. We examined the patterns of adherence to a yearlong exercise intervention and the influence of demographic, physiologic, and psychosocial variables on patterns of adherence among 173 sedentary, overweight, postmenopausal women. Methods. We collected demographic, physical activity (PA), physiologic, psychosocial, and medical history information at baseline and 12 months. The exercise prescription consisted of at least 45 min of moderate-intensity exercise 5 days/week for 12 months. We calculated several adherence variables. Associations between baseline variables and adherence levels were assessed in bivariate analyses and in multiple regression models. Results. Women randomized to the exercise group ( N = 87) participated in moderate-intensity sports or recreational PA on 3.7 ± 1.4 days/week (79% of the prescribed 5 days/week) for 171 ± 88 min/week (87% of the prescribed 225 min/week) over the yearlong trial period. Sixty-eight percent of the exercisers had a yearlong average PA level exceeding the national recommendation of 150 min/week. Being in the preparation stage vs. the contemplation stage of the transtheoretical model and a history of participating in any sports or recreational PA were significant predictors of adherence. Conclusions. Our findings provide important information for the design of future PA interventions and health promotion programs.

Effect of Exercise on Total and Intraabdominal Body Fat in Postmenopausal Women: A Randomized, Controlled Trial

Irwin, Melinda L.; Yasui, Yutaka; Ulrich, Cornelia M.; Bowen, Deborah; Rudolph, Rebecca E.; Schwartz, Robert S.; Yukawa, Michi; Aiello, Erin; Potter, John D.; McTiernan, Anne