Our meta analysis of a homogeneous set of studies is the first to provide valuable LLNs for fiber CSA according to fiber type and gender .
Skeletal muscle atrophy is a major systemic impairment in chronic diseases .
Yet its determinants have been hard to identify because a clear research definition has not been agreed upon .
The reduction in muscle fiber cross-sectional area ( CSA ) is a widely acknowledged marker of muscle atrophy , but no reference values for the muscle fiber CSA at the age of the onset of chronic disease have ever been published .
Comparison of lifestyle and structured interventions to increase physical activity and cardiorespiratory fitness: a randomized trial.
CONTEXT Even though the strong association between physical inactivity and ill health is well documented , 60 % of the population is inadequately active or completely inactive . Traditional methods of prescribing exercise have not proven effective for increasing and maintaining a program of regular physical activity . OBJECTIVE To compare the 24-month intervention effects of a lifestyle physical activity program with traditional structured exercise on improving physical activity , cardiorespiratory fitness , and cardiovascular disease risk factors . DESIGN R and omized clinical trial conducted from August 1 , 1993 , through July 31 , 1997 . PARTICIPANTS Sedentary men ( n = 116 ) and women ( n = 119 ) with self-reported physical activity of less than 36 and 34 kcal/kg per day , respectively . INTERVENTIONS Six months of intensive and 18 months of maintenance intervention on either a lifestyle physical activity or a traditional structured exercise program . MAIN OUTCOME MEASURES Primary outcomes were physical activity assessed by the 7-Day Physical Activity Recall and peak oxygen consumption ( VO2peak ) by a maximal exercise treadmill test . Secondary outcomes were plasma lipid and lipoprotein cholesterol concentrations , blood pressure , and body composition . All measures were obtained at baseline and at 6 and 24 months . RESULTS Both the lifestyle and structured activity groups had significant and comparable improvements in physical activity and cardiorespiratory fitness from baseline to 24 months . Adjusted mean changes ( 95 % confidence intervals [ CIs ] ) were 0.84 ( 95 % CI , 0.42 - 1.25 kcal/kg per day ; P<.001 ) and 0.69 ( 95 % CI , 0.25 - 1.12 kcal/kg day ; P = .002 ) for activity , and 0.77 ( 95 % CI , 0.18 - 1.36 mL/kg per minute ; P = .01 ) and 1.34 ( 95 % CI , 0.72 - 1.96 mL/kg per minute ; P<.001 ) for VO2peak for the lifestyle and structured activity groups , respectively . There were significant and comparable reductions in systolic blood pressure ( -3.63 [ 95 % CI , -5.54 to -1.72 mm Hg ; P<.001 ] and -3.26 [ 95 % CI , -5.26 to -1.25 mm Hg ; P = .002 ] ) and diastolic blood pressure ( -5.38 [ 95 % CI , -6.90 to -3.86 mm Hg ; P<.001 ] and -5.14 [ 95 % CI , -6.73 to -3.54 mm Hg ; P<.001 ) for the lifestyle and structured activity groups , respectively . Neither group significantly changed their weight ( -0.05 [ 95 % CI , -1.05 to 0.96 kg ; P = .93 ] and 0.69 [ 95 % CI , -0.37 to 1.74 kg ; P = .20 ] ) , but each group significantly reduced their percentage of body fat ( -2.39 % [ 95 % CI , -2.92 % to -1.85 % ; P<.001 ] and -1.85 % [ 95 % CI , -2.41 % to -1.28 % ; P<.001 ] ) in the lifestyle and structured activity groups , respectively . CONCLUSIONS In previously sedentary healthy adults , a lifestyle physical activity intervention is as effective as a structured exercise program in improving physical activity , cardiorespiratory fitness , and blood pressure
Our meta analysis of a homogeneous set of studies is the first to provide valuable LLNs for fiber CSA according to fiber type and gender .
Skeletal muscle atrophy is a major systemic impairment in chronic diseases .
Yet its determinants have been hard to identify because a clear research definition has not been agreed upon .
The reduction in muscle fiber cross-sectional area ( CSA ) is a widely acknowledged marker of muscle atrophy , but no reference values for the muscle fiber CSA at the age of the onset of chronic disease have ever been published .