Kathryn H. Schmitz

Compendium of physical activities: an update of activity codes and MET intensities.

We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code that describes physical activities by major headings (e.g., occupation, transportation, etc.) and specific activities within each major heading with its intensity, defined as the ratio of work metabolic rate to a standard resting metabolic rate (MET). Energy expenditure in MET-minutes, MET-hours, kcal, or kcal per kilogram body weight can be estimated for specific activities by type or MET intensity. Additions to the Compendium were obtained from studies describing daily PA patterns of adults and studies measuring the energy cost of specific physical activities in field settings. The updated version includes two new major headings of volunteer and religious activities, extends the number of specific activities from 477 to 605, and provides updated MET intensity levels for selected activities.

An update of controlled physical activity trials in cancer survivors: a systematic review and meta-analysis

IntroductionApproximately 11.1 million cancer survivors are alive in the United States. Activity prescriptions for cancer survivors rely on evidence as to whether exercise during or after treatment results in improved health outcomes. This systematic review and meta-analysis evaluates the extent to which physical activity during and post treatment is appropriate and effective across the cancer control continuum.MethodsA systematic quantitative review of the English language scientific literature searched controlled trials of physical activity interventions in cancer survivors during and post treatment. Data from 82 studies were abstracted, weighted mean effect sizes (WMES) were calculated from 66 high quality studies, and a systematic level of evidence criteria was applied to evaluate 60 outcomes. Reports of adverse events were abstracted from all studies.ResultsQuantitative evidence shows a large effect of physical activity interventions post treatment on upper and lower body strength (WMES = 0.99 & 0.90, p < 0.0001 & 0.024, respectively) and moderate effects on fatigue and breast cancer-specific concerns (WMES = −0.54 & 0.62, p = 0.003 & 0.003, respectively). A small to moderate positive effect of physical activity during treatment was seen for physical activity level, aerobic fitness, muscular strength, functional quality of life, anxiety, and self-esteem. With few exceptions, exercise was well tolerated during and post treatment without adverse events.ConclusionsCurrent evidence suggests many health benefits from physical activity during and post cancer treatments. Additional studies are needed in cancer diagnoses other than breast and with a focus on survivors in greatest need of improvements for the health outcomes of interest.

Controlled Physical Activity Trials in Cancer Survivors: A Systematic Review and Meta-analysis

Background: Approximately 9.8 million cancer survivors are alive in the United States today. Enthusiasm for prescribing physical activity for cancer survivors depends on evidence regarding whether physical activity during or after completion of treatment results in improved outcomes such as cardiorespiratory fitness, fatigue, symptoms, quality of life, mental health, or change in body size. Methods: A systematic qualitative and quantitative review of the English language scientific literature identified controlled trials of physical activity interventions in cancer survivors during and after treatment. Data from 32 studies were abstracted, weighted mean effect sizes (WMES) were calculated from the 22 high-quality studies, and a systematic level of evidence criteria was applied to evaluate 25 outcomes. Results: There was qualitative and quantitative evidence of a small to moderate effect of physical activity interventions on cardiorespiratory fitness (WMES = 0.51 and 0.65 during and after treatment respectively, P < 0.01), physiologic outcomes and symptoms during treatment (WMES = 0.28, P < 0.01 and 0.39, P < 0.01, respectively), and vigor posttreatment (WMES = 0.83, P = 0.04). Physical activity was well tolerated in cancer survivors during and after treatment, but the available literature does not allow conclusions to be drawn regarding adverse events from participation. Conclusions: Physical activity improves cardiorespiratory fitness during and after cancer treatment, symptoms and physiologic effects during treatment, and vigor posttreatment. Additional physical activity intervention studies are needed to more firmly establish the range and magnitude of positive effects of physical activity among cancer survivors.

Defining Accelerometer Thresholds for Activity Intensities in Adolescent Girls

Implications for Muscle Lipid Metabolism and An accumulation of intramuscular lipid has been reported with obesity and linked with insulin resistance. The purpose of this paper is to discuss: 1) mechanisms that may be responsible for intramuscular lipid accumulation with obesity, and 2) the effects of common interventions (weight loss or exercise) for obesity on skeletal muscle lipid metabolism and intramuscular lipid content. Data suggest that the skeletal muscle of morbidly obese humans is characterized by the preferential partitioning of lipid toward storage rather than oxidation. This phenotype may, in part, contribute to increased lipid deposition in both muscle and adipose tissue, and promote the development of morbid obesity and insulin resistance. Weight loss intervention decreases intramuscular lipid content, which may contribute to improved insulin action. On the other hand, exercise training improves insulin action and increases fatty acid oxidation in the skeletal muscle of obese/morbidly obese individuals. In summary, the accumulation of intramuscular lipid appears to be detrimental in terms of inducing insulin resistance; however, the accumulation of lipid can be reversed with weight loss. The mechanism(s) by which exercise enhances insulin action remains to be determined.INTRODUCTION/PURPOSE The Talk Test has been shown to be well correlated with the ventilatory threshold, with accepted guidelines for exercise prescription, and with the ischemic threshold. As such, it appears to be a valuable although quite simple method of exercise prescription. In this study, we evaluate the consistency of the Talk Test by comparing responses during different modes of exercise. METHODS Healthy volunteers (N = 16) performed incremental exercise, on both treadmill and cycle ergometer. Trials were performed with respiratory gas exchange and while performing the Talk Test. Comparisons were made regarding the correspondence of the last positive, equivocal, and first negative stages of the Talk Test with ventilatory threshold. RESULTS The %VO2peak, %VO2 reserve, %HRpeak, and %HR reserve at ventilatory threshold on treadmill versus cycle ergometer (77%, 75%. 89%, and 84% vs 67%, 64%, 82%, and 74%) were not significantly different than the equivocal stage of the Talk Test (83%, 82%, 86%, and 80% vs 73%, 70%, 87%, and 81%). The VO2 at ventilatory threshold and the last positive, equivocal and negative stages of the Talk Test were well correlated during treadmill and cycle ergometer exercise. CONCLUSIONS The results support the hypothesis that the Talk Test approximates ventilatory threshold on both treadmill and cycle. At the point where speech first became difficult, exercise intensity was almost exactly equivalent to ventilatory threshold. When speech was not comfortable, exercise intensity was consistently above ventilatory threshold. These results suggest that the Talk Test may be a highly consistent method of exercise prescription.INTRODUCTION Obesity and weight gain are negative prognostic factors for breast cancer survival. Physical activity (PA) prevents weight gain and may decrease obesity. Little information exists on PA levels among cancer survivors. We assessed PA, including the proportion of breast cancer survivors engaging in recommended levels, by categories of adiposity, age, disease stage, and ethnicity in 806 women with stage 0-IIIA breast cancer participating in the Health, Eating, Activity, and Lifestyle Study. METHODS Black, non-Hispanic white, and Hispanic breast cancer survivors were recruited into the study through Surveillance Epidemiology End Results registries in New Mexico, Western Washington, and Los Angeles County, CA. Types of sports and household activities and their frequency and duration within the third yr after diagnosis were assessed during an in-person interview. RESULTS Thirty-two percent of breast cancer survivors participated in recommended levels of PA defined as 150 min x wk(-1) of moderate- to vigorous-intensity sports/recreational PA. When moderate-intensity household and gardening activities were included in the definition, 73% met the recommended level of PA. Fewer obese breast cancer survivors met the recommendation than overweight and lean breast cancer survivors (P < 0.05). Fewer black breast cancer survivors met the recommendation compared with non-Hispanic white and Hispanic breast cancer survivors (P < 0.05). CONCLUSIONS Most of the breast cancer survivors were not meeting the PA recommendations proposed for the general adult population. Efforts to encourage and facilitate PA among these women would be an important tool to decrease obesity, prevent postdiagnosis weight gain, and improve breast cancer prognosis.PURPOSE To derive a regression equation that estimates metabolic equivalent (MET) from accelerometer counts, and to define thresholds of accelerometer counts that can be used to delineate sedentary, light, moderate, and vigorous activity in adolescent girls. METHODS Seventy-four healthy 8th grade girls, age 13 - 14 yr, were recruited from urban areas of Baltimore, MD, Minneapolis/St. Paul, MN, and Columbia, SC, to participate in the study. Accelerometer and oxygen consumption (.-)VO(2)) data for 10 activities that varied in intensity from sedentary (e.g., TV watching) to vigorous (e.g., running) were collected. While performing these activities, the girls wore two accelerometers, a heart rate monitor and a Cosmed K4b2 portable metabolic unit for measurement of (.-)VO(2). A random-coefficients model was used to estimate the relationship between accelerometer counts and (.-)VO(2). Activity thresholds were defined by minimizing the false positive and false negative classifications. RESULTS The activities provided a wide range in (.-)VO(2) (3 - 36 mL x kg x min) with a correspondingly wide range in accelerometer counts (1- 3928 counts x 30 s). The regression line for MET score versus counts was MET = 2.01 +/- 0.00171 (counts x 30 s) (mixed model R = 0.84, SEE = 1.36). A threshold of 1500 counts x 30 s defined the lower end of the moderate intensity (approximately 4.6 METs) range of physical activity. That cutpoint distinguished between slow and brisk walking, and gave the lowest number of false positive and false negative classifications. The threshold ranges for sedentary, light, moderate, and vigorous physical activity were found to be 0 - 50, 51- 1499, 1500 - 2600, and >2600 counts x 30 s, respectively. CONCLUSION The developed equation and these activity thresholds can be used for prediction of MET score from accelerometer counts and participation in various intensities of physical activity in adolescent girls.

Weight Lifting in Women with Breast-Cancer–Related Lymphedema

BACKGROUND Weight lifting has generally been proscribed for women with breast-cancer-related lymphedema, preventing them from obtaining the well-established health benefits of weight lifting, including increases in bone density. METHODS We performed a randomized, controlled trial of twice-weekly progressive weight lifting involving 141 breast-cancer survivors with stable lymphedema of the arm. The primary outcome was the change in arm and hand swelling at 1 year, as measured through displaced water volume of the affected and unaffected limbs. Secondary outcomes included the incidence of exacerbations of lymphedema, number and severity of lymphedema symptoms, and muscle strength. Participants were required to wear a well-fitted compression garment while weight lifting. RESULTS The proportion of women who had an increase of 5% or more in limb swelling was similar in the weight-lifting group (11%) and the control group (12%) (cumulative incidence ratio, 1.00; 95% confidence interval, 0.88 to 1.13). As compared with the control group, the weight-lifting group had greater improvements in self-reported severity of lymphedema symptoms (P=0.03) and upper- and lower-body strength (P<0.001 for both comparisons) and a lower incidence of lymphedema exacerbations as assessed by a certified lymphedema specialist (14% vs. 29%, P=0.04). There were no serious adverse events related to the intervention. CONCLUSIONS In breast-cancer survivors with lymphedema, slowly progressive weight lifting had no significant effect on limb swelling and resulted in a decreased incidence of exacerbations of lymphedema, reduced symptoms, and increased strength. (ClinicalTrials.gov number, NCT00194363.)

A Two-Year Randomized Trial of Obesity Treatment in Primary Care Practice

BACKGROUND Calls for primary care providers (PCPs) to offer obese patients behavioral weight-loss counseling have not been accompanied by adequate guidance on how such care could be delivered. This randomized trial compared weight loss during a 2-year period in response to three lifestyle interventions, all delivered by PCPs in collaboration with auxiliary health professionals (lifestyle coaches) in their practices. METHODS We randomly assigned 390 obese adults in six primary care practices to one of three types of intervention: usual care, consisting of quarterly PCP visits that included education about weight management; brief lifestyle counseling, consisting of quarterly PCP visits combined with brief monthly sessions with lifestyle coaches who instructed participants about behavioral weight control; or enhanced brief lifestyle counseling, which provided the same care as described for the previous intervention but included meal replacements or weight-loss medication (orlistat or sibutramine), chosen by the participants in consultation with the PCPs, to potentially increase weight loss. RESULTS Of the 390 participants, 86% completed the 2-year trial, at which time, the mean (±SE) weight loss with usual care, brief lifestyle counseling, and enhanced brief lifestyle counseling was 1.7±0.7, 2.9±0.7, and 4.6±0.7 kg, respectively. Initial weight decreased at least 5% in 21.5%, 26.0%, and 34.9% of the participants in the three groups, respectively. Enhanced lifestyle counseling was superior to usual care on both these measures of success (P=0.003 and P=0.02, respectively), with no other significant differences among the groups. The benefits of enhanced lifestyle counseling remained even after participants given sibutramine were excluded from the analyses. There were no significant differences between the intervention groups in the occurrence of serious adverse events. CONCLUSIONS Enhanced weight-loss counseling helps about one third of obese patients achieve long-term, clinically meaningful weight loss. (Funded by the National Heart, Lung, and Blood Institute; POWER-UP ClinicalTrials.gov number, NCT00826774.).

Randomized controlled trial of weight training and lymphedema in breast cancer survivors.

PURPOSE Lymphedema is a common condition that breast cancer survivors face. Despite a lack of supporting evidence from prospective observational studies, occupational and leisure time physical activity are feared to be possible risk factors for lymphedema onset or exacerbation. We examined effects of supervised upper- and lower-body weight training on the incidence and symptoms of lymphedema in 45 breast cancer survivors who participated in the Weight Training for Breast Cancer Survivors study. METHODS Participants were on average 52 years old, 4 to 36 months post-treatment, and had axillary dissection as part of their treatment. Thirteen women had prevalent lymphedema at baseline. The intervention was twice-a-week weight training over a period of 6 months. Lymphedema was monitored at baseline and 6 months by measuring the circumference of each arm, and by self-report of symptoms and clinical diagnosis. RESULTS None of the intervention-group participants experienced a change in arm circumferences > or = 2.0 cm after a 6-month exercise intervention. Self-reported incidence of a clinical diagnosis of lymphedema or symptom changes over 6 months did not vary by intervention status (P = .40 and P = .22, respectively). CONCLUSION This is the largest randomized controlled trial to examine associations between exercise and lymphedema in breast cancer survivors. The results of this study support the hypotheses that a 6-month intervention of resistance exercise did not increase the risk for or exacerbate symptoms of lymphedema. These results herald the need to start reevaluating common clinical guidelines that breast cancer survivors avoid upper body resistance activity for fear of increasing risk of lymphedema.

Safety and Efficacy of Weight Training in Recent Breast Cancer Survivors to Alter Body Composition, Insulin, and Insulin-Like Growth Factor Axis Proteins

Background: This randomized controlled trial assessed the safety and effects of twice-weekly weight training among recent breast cancer survivors. Outcomes included body size and biomarkers hypothesized to link exercise and breast cancer risk. Methods: A convenience sample of 85 recent survivors was randomized into immediate and delayed treatment groups. The immediate group trained from months 0 to 12; the delayed treatment group served as a no exercise parallel comparison group from months 0 to 6 and trained from months 7 to 12. Measures at baseline, 6 and 12 months included body weight, height, body fat, lean mass, body fat %, and waist circumference, as well as fasting glucose, insulin, insulin resistance, insulin-like growth factor-I (IGF-I), IGF-II, and IGF-binding protein-1, IGFBP-2, and IGFBP-3. Injury reporting was standardized. Results: The intervention resulted in significant increases in lean mass (0.88 versus 0.02 kg, P < 0.01), as well as significant decreases in body fat % (−1.15% versus 0.23%, P = 0.03) and IGF-II (−6.23 versus 28.28 ng/mL, P = 0.02) comparing immediate with delayed treatment from baseline to 6 months. Within-person changes experienced by delayed treatment group participants during training versus no training were similar. Only one participant experienced a study related injury that prevented continued participation. Conclusion: Twice-weekly weight training is a safe exercise program for recent breast cancer survivors that may result in increased muscle mass, as well as decreased body fat % and IGF-II. The implications of these results on cancer recurrence or survival may become more evident with longer exercise intervention trials among breast cancer survivors.

Lymphedema and Quality of Life in Breast Cancer Survivors: The Iowa Women's Health Study

PURPOSE The impact of lymphedema or related arm symptoms on health-related quality of life (HRQOL) in breast cancer (BrCa) survivors has not been examined using a large population-based cohort. PATIENTS AND METHODS The Iowa Womens Health Study (IWHS) collected self-report data for lymphedema, arm symptoms, and HRQOL (Medical Outcomes Study Short Form-36) in 2004 and data for cancer diagnosis, treatment, and behavioral and health characteristics between 1986 and 2003. We studied 1,287 women, age 55 to 69 years at baseline, who developed unilateral BrCa. We used cross-sectional analyses to describe the prevalence of lymphedema and arm symptoms and multivariate-adjusted generalized linear models to compare HRQOL (physical functioning, bodily pain, general health, physical and emotional role limitations, vitality, social functioning, and mental health) between the following three survivor groups: women with lymphedema (n = 104), women with arm symptoms without diagnosed lymphedema (n = 475), and women without lymphedema or arm symptoms (n = 708). RESULTS The mean (+/- SE) time between BrCa diagnosis and lymphedema survey was 8.1 +/- 0.2 years. Of BrCa survivors, 8.1% self-reported diagnosed lymphedema, and 37.2% self-reported arm symptoms. Knowledge of lymphedema was low among survivors without diagnosed lymphedema (n = 1,183). After multivariate adjustment, women with diagnosed lymphedema or arm symptoms without diagnosed lymphedema had lower physical and mental HRQOL compared with women without lymphedema or arm symptoms. Effect sizes were mild to moderate. There was a dose-response relation between number of arm symptoms and lower HRQOL. CONCLUSION In the IWHS, HRQOL was lower for BrCa survivors with diagnosed lymphedema and for those with arm symptoms without diagnosed lymphedema. Clinical trials are needed to determine what interventions can improve lymphedema and impact HRQOL for BrCa survivors.

Weight Lifting for Women at Risk for Breast Cancer–Related Lymphedema: A Randomized Trial

CONTEXT Clinical guidelines for breast cancer survivors without lymphedema advise against upper body exercise, preventing them from obtaining established health benefits of weight lifting. OBJECTIVE To evaluate lymphedema onset after a 1-year weight lifting intervention vs no exercise (control) among survivors at risk for breast cancer-related lymphedema (BCRL). DESIGN, SETTING, AND PARTICIPANTS A randomized controlled equivalence trial (Physical Activity and Lymphedema trial) in the Philadelphia metropolitan area of 154 breast cancer survivors 1 to 5 years postunilateral breast cancer, with at least 2 lymph nodes removed and without clinical signs of BCRL at study entry. Participants were recruited between October 1, 2005, and February 2007, with data collection ending in August 2008. INTERVENTION Weight lifting intervention included a gym membership and 13 weeks of supervised instruction, with the remaining 9 months unsupervised, vs no exercise. MAIN OUTCOME MEASURES Incident BCRL determined by increased arm swelling during 12 months (≥5% increase in interlimb difference). Clinician-defined BCRL onset was also evaluated. Equivalence margin was defined as doubling of lymphedema incidence. RESULTS A total of 134 participants completed follow-up measures at 1 year. The proportion of women who experienced incident BCRL onset was 11% (8 of 72) in the weight lifting intervention group and 17% (13 of 75) in the control group (cumulative incidence difference [CID], -6.0%; 95% confidence interval [CI], -17.2% to 5.2%; P for equivalence = .04). Among women with 5 or more lymph nodes removed, the proportion who experienced incident BCRL onset was 7% (3 of 45) in the weight lifting intervention group and 22% (11 of 49) in the control group (CID, -15.0%; 95% CI, -18.6% to -11.4%; P for equivalence = .003). Clinician-defined BCRL onset occurred in 1 woman in the weight lifting intervention group and 3 women in the control group (1.5% vs 4.4%, P for equivalence = .12). CONCLUSION In breast cancer survivors at risk for lymphedema, a program of slowly progressive weight lifting compared with no exercise did not result in increased incidence of lymphedema. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00194363.