quarta-feira, 24 de abril de 2013

HIGH-INTENSITY CIRCUIT TRAINING USING BODY WEIGHT: Maximum Results With Minimal Investment

Klika, Brett C.S.C.S., B.S.; Jordan, Chris M.S., C.S.C.S., NSCA-CPT, ACSM HFS/APT


Abstract

LEARNING OBJECTIVE: To understand the health benefits and practical application of a high-intensity circuit training exercise protocol.


http://journals.lww.com/acsm-healthfitness/Fulltext/2013/05000/HIGH_INTENSITY_CIRCUIT_TRAINING_USING_BODY_WEIGHT_.5.aspx

Steps/day translation of the moderate-to-vigorous physical activity guideline for children and adolescents

Marc A Adams (marc.adams@asu.edu)
William D Johnson (William.Johnson@pbrc.edu)
Catrine Tudor-Locke (Catrine.Tudor-Locke@pbrc.edu)

Abstract 
Background 
An evidence-based steps/day translation of U.S. federal guidelines for youth to engage in ≥60 
minutes/day of moderate-to-vigorous physical activity (MVPA) would help health 
researchers, practitioners, and lay professionals charged with increasing youth’s physical 
activity (PA). The purpose of this study was to determine the number of free-living steps/day 
(both raw and adjusted to a pedometer scale) that correctly classified children (6–11 years) 
and adolescents (12–17 years) as meeting the 60-minute MVPA guideline using the 2005–
2006 National Health and Nutrition Examination Survey (NHANES) accelerometer data, and 
to evaluate the 12,000 steps/day recommendation recently adopted by the President’s 
Challenge Physical Activity and Fitness Awards Program. 
Methods 
Analyses were conducted among children (n = 915) and adolescents (n = 1,302) in 2011 and 
2012. Receiver Operating Characteristic (ROC) curve plots and classification statistics 
revealed candidate steps/day cut points that discriminated meeting/not meeting the MVPA 
threshold by age group, gender and different accelerometer activity cut points. The Evenson 
and two Freedson age-specific (3 and 4 METs) cut points were used to define minimum 
MVPA, and optimal steps/day were examined for raw steps and adjusted to a pedometerscale to facilitate translation to lay populations. Results 
For boys and girls (6–11 years) with ≥ 60 minutes/day of MVPA, a range of 11,500–13,500 
uncensored steps/day for children was the optimal range that balanced classification errors. 
For adolescent boys and girls (12–17) with ≥60 minutes/day of MVPA, 11,500–14,000 
uncensored steps/day was optimal. Translation to a pedometer-scaling reduced these 
minimum values by 2,500 step/day to 9,000 steps/day. Area under the curve was ≥84% in all 
analyses. 
Conclusions 
No single study has definitively identified a precise and unyielding steps/day value for youth. 
Considering the other evidence to date, we propose a reasonable ‘rule of thumb’ value of ≥
11,500 accelerometer-determined steps/day for both children and adolescents (and both 
genders), accepting that more is better. For practical applications, 9,000 steps/day appears to 
be a more pedometer-friendly value. 

http://www.ijbnpa.org/content/pdf/1479-5868-10-49.pdf

Motivational interviewing and problem solving treatment to reduce type 2 diabetes and cardiovascular disease risk in real life: a randomized controlled trial


Jeroen Lakerveld (j.lakerveld@vumc.nl)
Sandra D Bot (s.bot@vumc.nl)
Mai J Chinapaw (m.chinapaw@vumc.nl)
Maurits W van Tulder (maurits.van.tulder@falw.vu.nl)
Piet J Kostense (pj.kostense@vumc.nl)
Jacqueline M Dekker (jm.dekker@vumc.nl)
Giel Nijpels (g.nijpels@vumc.nl)


Abstract
Background
Intensive lifestyle interventions in well-controlled settings are effective in lowering the risk
of chronic diseases such as type 2 diabetes (T2DM) and cardiovascular diseases (CVD), but
there are still no effective lifestyle interventions for everyday practice. In the Hoorn
Prevention Study we aimed to assess the effectiveness of a primary care based lifestyle
intervention to reduce the estimated risk of developing T2DM and for CVD mortality, and to
motivate changes in lifestyle behaviors.
Methods
The Hoorn Prevention Study is a parallel group randomized controlled trial, implemented in
the region of West-Friesland, the Netherlands. 622 adults with ≥10% estimated risk of T2DM
and/or CVD mortality were randomly assigned and monitored over a period of 12 months.
The intervention group (n=314) received a theory-based lifestyle intervention based on an
innovative combination of motivational interviewing and problem solving treatment,
provided by trained practice nurses in 12 general practices. The control group (n=308)
received existing health brochures. Primary outcomes was the estimated diabetes risk
according to the formula of the Atherosclerosis Risk In Communities (ARIC) Study, and the
estimated risk for CVD mortality according to the Systematic COronary Risk Evaluation
(SCORE) formula. Secondary outcomes included lifestyle behavior (diet, physical activity
and smoking). The research assistants, the principal investigator and the general practitioners
were blinded to group assignment. Linear and logistic regression analysis was applied to
examine the between-group differences in each outcome measure, adjusted for baseline
values.
Results
536 (86.2%) of the 622 participants (age 43.5 years) completed the 6-month follow-up, and
502 (81.2%) completed the 12-month follow-up. The mean baseline T2DM risk was 18.9%
(SD 8.2) and the mean CVD mortality risk was 3.8% (SD 3.0). The intervention group
participated in a median of 2 sessions. Intention-to-treat analyses showed no significant
differences in outcomes between the two groups at 6 or 12-months follow-up.
Conclusions
The lifestyle intervention was not more effective than health brochures in reducing risk
scores for T2DM and CVD or improving lifestyle behavior in an at-risk population.
Trial registration
Current Controlled Trials: ISRCTN59358434



http://www.ijbnpa.org/content/pdf/1479-5868-10-47.pdf

sexta-feira, 19 de abril de 2013

Walking Versus Running for Hypertension, Cholesterol, and Diabetes Mellitus Risk Reduction


  1. Paul D. Thompson

Abstract

Objective—To test whether equivalent energy expenditure by moderate-intensity (eg, walking) and vigorous-intensity exercise (eg, running) provides equivalent health benefits.
Approach and Results—We used the National Runners’ (n=33 060) and Walkers’ (n=15 945) Health Study cohorts to examine the effect of differences in exercise mode and thereby exercise intensity on coronary heart disease (CHD) risk factors. Baseline expenditure (metabolic equivant hours per day [METh/d]) was compared with self-reported, physician-diagnosed incident hypertension, hypercholesterolemia, diabetes mellitus, and CHD during 6.2 years follow-up. Running significantly decreased the risks for incident hypertension by 4.2% (P<10−7), hypercholesterolemia by 4.3% (P<10−14), diabetes mellitus by 12.1% (P<10−5), and CHD by 4.5% per METh/d (P=0.05). The corresponding reductions for walking were 7.2% (P<10−6), 7.0% (P<10−8), 12.3% (P<10−4), and 9.3% (P=0.01). Relative to <1.8 METh/d, the risk reductions for 1.8 to 3.6, 3.6 to 5.4, 5.4 to 7.2, and ≥7.2 METh/d were as follows: (1) 10.1%, 17.7%, 25.1%, and 34.9% from running and 14.0%, 23.8%, 21.8%, and 38.3% from walking for hypercholesterolemia; (2) 19.7%, 19.4%, 26.8%, and 39.8% from running and 14.7%, 19.1%, 23.6%, and 13.3% from walking for hypertension; and (3) 43.5%, 44.1%, 47.7%, and 68.2% from running, and 34.1%, 44.2% and 23.6% from walking for diabetes mellitus (walking >5.4 METh/d excluded for too few cases). The risk reductions were not significantly different for running than walking for diabetes mellitus (P=0.94), hypertension (P=0.06), or CHD (P=0.26), and only marginally greater for walking than running for hypercholesterolemia (P=0.04).
Conclusions—Equivalent energy expenditures by moderate (walking) and vigorous (running) exercise produced similar risk reductions for hypertension, hypercholesterolemia, diabetes mellitus, and possibly CHD.


http://atvb.ahajournals.org/content/33/5/1085.short

http://atvb.ahajournals.org/content/suppl/2013/04/04/ATVBAHA.112.300878.DC2/ATV201776_Supplemental_Material1.pdf

segunda-feira, 15 de abril de 2013

Motivation, self-determination, and long-term weight control


Abstract

This article explores the topics of motivation and self-regulation in the context of weight management and related behaviors. We focus on the role of a qualitative approach to address motivation - not only considering the level but also type of motivation - in weight control and related behaviors. We critically discuss the operationalization of motivation in current weight control programs, present a complementary approach to understanding motivation based on self-determination theory, and review empirical findings from weight control studies that have used self-determination theory measures and assessed their association with weight outcomes. Weight loss studies which used Motivational Interviewing (MI) are also reviewed, considering MI's focus on enhancing internal motivation. We hypothesize that current weight control interventions may have been less successful with weight maintenance in part due to their relative disregard of qualitative dimensions of motivation, such as level of perceived autonomy, often resulting in a motivational disconnect between weight loss and weight-related behaviors. We suggest that if individuals fully endorse weight loss-related behavioral goals and feel not just competent but also autonomous about reaching them, as suggested by self-determination theory, their efforts are more likely to result in long-lasting behavior change.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3312817/

Self-Regulation, Motivation, and Psychosocial Factors in Weight Management


Any attempt to self-regulate one's body weight takes place at the intersection of the external environment and innate biological predispositions that, especially when combined, can be highly conducive to energy surpluses and excessive fat mass accretion. Prominent examples of such factors are high availability of calorie dense, palatable foods, economical constraints that negatively influence lifestyle choices, and the human predisposition for liking sweet and fatty foods. As a consequence, it is no surprise that the majority of individuals have become overweight or obese, apparently “losing control” and “succumbing” to these external and internal obesogenic pressures. At the same time, it is known that behaviors related to body weight regulation, namely, physical activity and diet, are generally within the reach of voluntary control and regulation, as evidenced by studies of successful weight loss maintainers who report dramatic changes in their lifestyles despite being surrounded by seemingly obesogenic environments []. These improvements have frequently been linked to individuals finding new ways of relating to one's weight and lifestyle, new self-perceptions, motives, goals, emotional responses, habits, and so forth (e.g., []). This apparent paradox is reinforced by a frequent tension between population-level (“environmental,” “political”) versus individual-level (“motivational,” “self-regulatory”) approaches to addressing the problem of obesity, which may be misguided; both will likely be necessary and one can inform the other.
Various perspectives can be taken to address obesity prevention and treatment. One is that obesity, at a population level, is largely “caused” by environmental factors and consequently it should primarily be tackled with public health measures []. Other views, informed by advances in molecular biology, tend to favor approaches rooted in the genetics of obesity (e.g., prevention by early risk diagnosis) [] and/or pharmacological solutions to treat the most prevalent forms of obesity []. Lately, interventions derived from applying principles of behavioral economics have come forth with solutions based on “nudges” and small changes in contextual “default conditions,” as they bypass individuals' volition, biases, and errors in judgment []. While other perspectives exist (e.g., []), this special issue is a statement that exploring psychological determinants of health behavior such as reasons, goals, expectations, values, beliefs, or self-perceptions - and getting individuals more (and better) motivated in self-managing their health, remain important aspects to address in fighting obesity. While, in concept, no one disputes that motivational factors or, more generally, psychosocial processes are relevant to understanding why people behave the way they do, in regards to their health, this topic has sometimes been presented as “old news” in obesity research, which is premature. We believe that a more productive stance is one that recognizes that a multitude of perspectives and solutions must be effectively integrated in order to more successfully fight obesity [].
Environmental change may be slow to implement, can be very expensive, is often stalled by industries with competing interests, and can have unpredictable and even paradoxical outcomes, all of which makes research in this area a formidable challenge []. Furthermore, social and economical conditions will evolve, and many people will move across different physical and cultural environments through the course of their lives (sometimes for long periods), which could limit the efficacy of some environmental interventions. Therefore, it is crucial to also improve existing strategies and develop new strategies that help people better navigate obesogenic environments, wherever and whenever they exist, by maximizing their own self-regulatory resources. Again, a critical point is that population-based initiatives to fight obesity can and should be informed by “individual-level” research (e.g., mass, internet-based campaigns to promote fruits and vegetables which apply sound theory-based motivational principles); similarly, “individual-level” interventions (e.g., primary care consultations) should be mindful of research findings in areas such as the impact of the built environment of physical activity or how contextual “nudges” impact health-related decisions and behavior. Regardless, all these initiatives must be supported by focused, high-quality research that seeks to understand why, how, and under which conditions children, adolescents, and adults are more likely to remain at, or achieve healthful levels of body weight. This special issue aims to make a contribution to this research.
The 14 articles published in this special issue underline the importance of psychological factors in the context of body weight self-regulation. For instance, L. Karhunen and colleagues [] show that psychobehavioral factors are more important for weight regulation than individual satiety levels or diet characteristics, whereas E. A. Dennis and colleagues [] point out the difficulty of maintaining weight during freshman year at college, even with explicit training in self-regulation skills. C. Bégin and colleagues [] demonstrate that self-regulation during weight loss attempts systematically differs between women with lower and higher depressive symptoms, underlining the importance of psychological health and wellbeing as a prerequisite in self-regulation of health behaviors.
Three articles investigate the role of self-perceived weight in adolescents. R. C. Krauss and colleagues [] show that accuracy differences in weight perceptions explain some of the weight disparities between adolescents of different ethnic groups in the US. K. Ojala and colleagues [] report that overweight boys and girls in Finland accurately perceived their weight as higher and had a lower body image than normal-weight children. Importantly, adolescents who perceived themselves as being overweight despite being in a healthy weight range were more likely to actually be overweight 11 years later [].
Three articles examine physical activity, a health behavior central in weight management. E. Guérin and M. S. Fortier [] showed how situational motivation and perceived exercise intensity predict changes in positive affect following physical activity. D. S. Buchan and colleagues [] reviewed current psychological models for increasing physical activity levels and describe the need for more ecological models. M. L. Segar and colleagues [] show that framing physical activity as a way to positively influence daily well-being enhanced body image and perceptions about the physical activity experience in overweight women.
Three articles investigate the role of the social environment for self-regulation of bodyweight, particularly, the role of parents in children's and adolescents' weight management. K. P. Jakubowski and colleagues [] showed that parental readiness to change weight control behaviors was predictive of adolescents' body mass index at treatment end. In their review, L. A. Frankel and S. O. Hughes [] made interesting connections, applying the literature on parental influence on their children's emotion regulation to parental influence on self-regulation of energy intake in children. These articles point to the importance of the interaction of the social environment (parents) with the self-regulation of weight-related behaviors in children and adolescents. S. B. Gesell and colleagues [] report on a different aspect of the parent-child relation in the context of weight management. They show that over the course of a three-month obesity prevention trial parents form new social ties with parents of children with similar body types. Thus, parents of obese children were more likely to become friends with parents of other obese children and parents of normal-weight children would befriend parents of other normal-weight children more often.
Another central topic in self-regulation is an individual's motivation. Two articles examined the role of external motivation, namely, monetary incentives for weight regulation. M. M. Crane and colleagues [] showed somewhat surprisingly that small monetary incentives did not influence autonomous or controlled motivation for participation in a 1-year weight loss trial. In contrast, the findings by A. C. Moller and colleagues [] demonstrate that participants in a three-week health behavior improvement program who reported being more motivated by a monetary incentive had higher body weight at 17 weeks followup. Finally, J. Y. Breland and colleagues [] suggest the Common-Sense Model of Self-Regulation as a framework for organizing existent tools and creating new means to improve long-term weight regulation.
We believe this special Issue will enhance our understanding of psychological—especially motivational and self-regulatory—factors in weight management and, collectively, provide an interesting snapshot of research in this area, with a good share of innovative empirical findings (e.g., []) and fresh conceptual discussions (e.g., []).
As a final note, it is important to remember, especially when dealing with issues involving individual self-regulation, that our society protects human freedom of choice. Biomedical ethics, the legal system in the US, and medical professionalism protect patient autonomy in health care and in research studies and have recently agreed that it should be a primary outcome of all health care interactions ([]). The need to respect patient autonomy in all health care interventions is mandated and thus is not a choice for whether practitioners, policy makers, or researchers will support it in a particular intervention. Thus, more research is needed to understand how autonomous self-regulation is affected by public health messaging, clinical and community programs, food industry advertising, economic rewards and punishments, and genetics. Also, health care is delivered in a free choice paradigm; thus, interventions must focus on helping participants to choose options that help them maintain their weight or weight loss and which they want to continue to choose after the intervention's end. To determine the success of an intervention, researchers are strongly encouraged to document the effect of their interventions for a period of at least 6 months after the intervention ends. For obesity, known for its high recidivism, this period might be even longer.
Pedro J. Teixeira
Jutta Mata
Geoffrey C. Williams
Amy A. Gorin
Simone Lemieux

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Articles from Journal of Obesity are provided here courtesy of Hindawi Publishing Corporation

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3503363/

quarta-feira, 10 de abril de 2013

Healthy School Lunches Cut Kids' Obesity Rates

By Nancy Walsh, Staff Writer, MedPage Today
Published: April 08, 2013
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse PlannerChildren residing in states with stringent nutritional standards for school meals had lower rates of obesity than those living in states with more lax regulations, researchers reported.

In states where school meal nutritional requirements fell below those currently recommended by the USDA, rates of obesity were doubled among children consuming reduced-price or free meals compared with children not eating school-provided lunches (26% versus 13.9%), according to Daniel R. Taber, PhD, and colleagues from the University of Illinois at Chicago.
In contrast, the difference in rates of obesity was much less pronounced in states exceeding the USDA nutritional standards (21.1% versus 17.4%), the researchers reported online in JAMA Pediatrics.
"In short, the study found an association between more stringent school meal standards and more favorable weight status, especially among low-income students," Marion Nestle, PhD, of New York University in New York City, wrote in an accompanying editorial.
More than 65 years ago, the National School Lunch Program was established to help meet the nutritional needs of children, and today some 30 million receive the lunches, either paying full price or at subsidized cost depending on family income.
In recent years, however, the program has been criticized for its quality, and some have argued that it has played a part in the pediatric obesity epidemic.
In answer to these challenges, the USDA established revised standards in 2012, calling for more vegetables, fruits, low-fat milk, and whole grains to be included in the meals, and for limits on calories and trans fats.
However, some states had already enacted laws requiring healthier meals. To see if those regulations had had any effect on childhood obesity rates, Taber's team compared 2006-2007 obesity rates in those states with rates in states with looser requirements.
Their analysis included 4,870 middle-school students in 40 states.
A total of 2,350 children paid full price for their lunches, 1,570 received the lunches at lower or no cost, and 950 didn't participate in the lunch program.
In an unadjusted analysis, the rate of obesity for those having a reduced-price lunch was 25.2%, while rates for those paying full price or not eating the school lunches were 16.3% and 14.3%, respectively.
Even after adjusting for socioeconomics, race, location, and other between-state variables, the prevalence was 3.7 points higher for the reduced-price group compared with children not participating in the lunch program.
Further analysis comparing obesity rates according to state nutrition requirements confirmed a decrease of 12.3 percentage points (95% CI −21.5 to −3) in the difference in obesity rates between children receiving subsidized lunches and those not eating school lunches in states exceeding USDA nutrition standards.
Similarly, the difference in mean percentile of body mass index between children in the reduced-price lunch group and nonparticipating children was lower in states with stringent requirements (β = −0.11, 95% CI −17.7 to −4.3).
The researchers also considered whether children in the more stringent states compensated by purchasing more unhealthy "competitive" sweet or salty snacks and sweetened beverages from widely available vending machines, and found little evidence to support this.
Nonetheless, they noted, "unless school meal laws are accompanied by nutrition education and initiatives to limit energy-dense competitive foods and beverages, then even the most stringent school meal standards may be undermined by competitive foods."
In her editorial, Nestle argued that some members of Congress have objected to the new USDA regulations on school meals -- largely at the behest of the food industry.
"Although the USDA based its nutrition standards on studies by the Institute of Medicine, when it comes to school food, politics trumps science," she wrote.
For instance, Congress has since forbidden the USDA from placing a limit on the number of servings of potatoes that are permissible and has insisted that the tomato sauce on pizza be considered a vegetable serving.
"Increasing evidence confirms that school-based dietary interventions can help promote healthier eating patterns and body weights, especially among children likely to bear the greatest consequences of obesity," Nestle observed.
"Objections to school nutrition standards must be recognized for what they do: place the financial health of food companies and their supporters in Congress above the health of the nation's children," she stated.
The study was limited by being cross-sectional and the possibility of confounding by factors at the state level.
The study was funded by the Robert Wood Johnson Foundation and the National Heart, Lung and Blood Institute.
The authors reported no conflicts of interest.


http://www.medpagetoday.com/Pediatrics/Obesity/38327

sexta-feira, 5 de abril de 2013

Run or Walk: Gains in Heart Health Similar

By Michael Smith, North American Correspondent, MedPage Today
Published: April 04, 2013
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

Walking and running have about the same health benefits, researchers found – you just have to walk more to get them.
Spending the same amount of energy yielded similar reductions in the risks of high blood pressure, high cholesterol, diabetes, and coronary heart disease, according to Paul Williams, PhD, of Lawrence Berkeley National Laboratory in Berkeley, Calif., and Paul Thompson, MD, of Hartford Hospital in Hartford, Conn.
But analysis of two large cohorts suggested that runners usually expend about twice as much energy as walkers and therefore reap greater health benefits, Williams and Thompson reported online in Arteriosclerosis, Thrombosis and Vascular Biology.
"The more the runners ran and the walkers walked, the better off they were in health benefits," Williams said in a statement. "If the amount of energy expended was the same between the two groups, then the health benefits were comparable."
"Walking may be a more sustainable activity for some people when compared to running," he added. "However, those who choose running end up exercising twice as much as those who choose walking ... probably because they can do twice as much in an hour."
Walking and running, the researchers noted, involve the same muscle groups and the same motions, but are performed at different "intensities" – where intensity is defined in terms of "metabolic equivalents," or METs.
Exercise has moderate intensity if it uses 3 to 6 times the oxygen needed to sit at rest, usually defined as 3.5 ml of oxygen per kg of body weight per minute. That amount is 1 MET.
On that scale, walking is moderate intensity exercise and running, which uses more than 6 METs, is vigorous, they noted.
What hasn't been clear is whether equivalent doses of moderate and vigorous physical activity have the same health benefits over time. To help fill that gap, Williams and Thompson turned to the National Runners' Health Study II and the National Walkers' Health Study.
In those cohorts, they looked for any associations of incident hypertension, hypercholesterolemia, diabetes, and coronary heart disease with reported exercise, with energy expenditure measured in MET-hours per day.
After excluding people with those conditions at the start, they were left with 15,945 walkers (21% of them men) and 33,060 runners (51.4% men). During 6.2 years of follow-up, there were 3,874 cases of incident hypertension, 6,637 cases of high cholesterol, 647 new cases of diabetes, and 530 cases of coronary heart disease.
Overall, they reported, male runners expended an average of 5.29 MET-hours per day while female runners expended 4.74. In contrast, male walkers expended 2.2 MET-hours per day and females expended 2.14.
The difference in average energy expenditure was reflected in lower health risks for runners, compared with walkers -- 38% lower for hypertension, 36% lower for hypercholesterolemia, and 71% lower for diabetes, they reported.
But equivalent energy expenditures cancelled out the differences. Specifically, per MET-hour per day, running and walking significantly decreased the risks for:
  • Incident hypertension by 4.2% for running and 7.2% for walking (P<10−7)
  • Hypercholesterolemia by 4.3% (P<10−14) and 7% (P<10−8)
  • Diabetes by 12.1% (P<10−5) and 12.3%, (P<10−4)
  • Coronary heart disease by 4.5%(P=0.05) and 9.3% (P=0.01)
The risk reductions were not significantly different for running than walking for diabetes (P=0.94) or coronary heart disease (P=0.26).
The researchers cautioned that the study cohort is a sample of convenience.
Although it's "unlikely" that the observed interaction would be different in a less-selected population, they wrote, "we cannot exclude" the possibility that people who exercise have lower innate risks for hypertension, high cholesterol, diabetes, or coronary heart disease.
Finally, information on diet and other possible confounding variables wasn't collected.
The study had support from the National Heart, Lung and Blood Institute. The journal said the authors reported no conflicts of interest.


http://www.medpagetoday.com/PrimaryCare/ExerciseFitness/38253