Low Cardiorespiratory Fitness and Physical Inactivity as Predictors of Mortality in Men with Type 2 Diabetes The influence of high-intensity compared with moderate-intensity exercise training on cardiorespiratory fitness and body composition in colorectal cancer survivors: a randomised controlled trial Influence of regular aerobic exercise on endothelium-dependent vasodilation and cardiorespiratory fitness in pregnant women. Effects of a Phase IV Home-Based Cardiac Rehabilitation Program on Cardiorespiratory Fitness and Physical Activity. A longitudinal study of cardiorespiratory fitness and cognitive function in healthy older adults. Changes in cardiorespiratory fitness, psychological wellbeing, quality of life, and vocational status following a 12 month cardiac exercise rehabilitation programme. Exercise therapy, cardiorespiratory fitness and their effect on brain volumes: A randomised controlled trial in patients with schizophrenia and healthy controls A Home- and Community-Based Physical Activity Program Can Improve the Cardiorespiratory Fitness and Walking Capacity of Stroke Survivors. Cardiorespiratory fitness and quality of life at different exercise intensities after myocardial infarction. Comparison of lifestyle and structured interventions to increase physical activity and cardiorespiratory fitness: a randomized trial. Changes in cardiorespiratory fitness and coronary heart disease risk factors following 24 wk of moderate- or high-intensity exercise of equal energy cost. Dose-Response of Aerobic Exercise on Cognition: A Community-Based, Pilot Randomized Controlled Trial The effect on cardiorespiratory fitness after an 8-week period of commuter cycling--a randomized controlled study in adults. Does aerobic exercise improve or impair cardiorespiratory fitness and health among cleaners? A cluster randomized controlled trial. The Effects of a Peer Modeling Intervention on Cardiorespiratory Fitness Parameters and Self-Efficacy in Obese Adolescents Moderately intense physical activities and high levels of cardiorespiratory fitness reduce the risk of non-insulin-dependent diabetes mellitus in middle-aged men. A randomized trial of physical activity interventions: design and baseline data from project active.
Exercise has become a st and ard therapy for patients with type 2 diabetes ( 1 ) . Regular exercise improves conventional clinical risk factors , cardiorespiratory fitness , and components of the insulin resistance syndrome ( 2 - 6 ) . However , it is unclear whether physical activity improves the prognosis of patients with diabetes . No data are available on the association of physical activity or cardiorespiratory fitness with mortality in patients with diabetes . The overall benefit of exercise for these patients is unclear , and some experts are concerned that macrovascular and microvascular complications may be worsened by an exercise program ( 1 , 7 ) . Some consider exercise only as a supplement to diet therapy ( 8) . Studies have shown repeatedly that low cardiorespiratory fitness and physical inactivity are directly associated with cardiovascular disease and all-cause mortality ( 9 - 14 ) , and our preliminary study with a small number of end points suggested that this association might persist across plasma glucose levels ( 15 ) . In the current study , we evaluated the prospect i ve association of cardiorespiratory fitness and physical inactivity with mortality in men who have type 2 diabetes . Methods The material presented in this report was derived from the Aerobics Center Longitudinal Study ( ACLS ) , a prospect i ve observational study of patients examined at The Cooper Clinic in Dallas , Texas . The study was review ed and approved annually by the institutional review board at The Cooper Institute . Additional details of study methods and study group characteristics of this cohort have been published elsewhere ( 12 , 13 ) . Patients Participants were men with type 2 diabetes who completed a baseline medical evaluation at The Cooper Clinic in Dallas , Texas , during 1970 to 1993 . These men came to The Cooper Clinic for a medical examination and health counseling . Many were sent by their employers for these services , some were referred by their personal physicians , and others were self-referred . More than 92 % of the patients are white , and most are employed in executive or professional occupations ; more than 75 % are college graduates . Study participants come from middle and upper socioeconomic strata , but they are similar to other well-characterized study group-based cohorts in terms of blood pressure , cholesterol level , body weight , and cardiorespiratory fitness ( 6 , 16 , 17 ) . We excluded men taking insulin and those with a history of cancer at baseline . Clinical Examination The baseline evaluation was performed after participants gave informed written consent for the baseline medical examination and registration in the follow-up study . Examinations followed an overnight fast of at least 12 hours and included personal and family health histories , a question naire on demographic characteristics and health habits , a physical examination , a maximal exercise test on a treadmill , anthropometry , electrocardiography , blood chemistry analyses , and blood pressure measurement . Technicians who followed a st and ard manual of operations administered all procedures . Question naire Patients completed an extensive self-report of personal and family medical diseases and conditions . Each clinic physician examines only four or five patients per day and thus has time for thorough additional probing of items on the self-reported question naire . This complete review of the patient 's medical history and the subsequent physical examination are strengths of the ACLS and provide a more thorough evaluation of baseline health status than is possible in many epidemiologic studies . The question naire also featured items on health habits , including current smoking status and smoking history and whether the participant was currently dieting to lose weight or following any other special dietary plan . Physical activity pattern was ascertained by self-report on the question naire . An extensive list of leisure-time physical activities was presented , and participants indicated activities in which they had participated in the 3 months before the examination . In later study years , they gave additional details on the number of times per week and the duration of exercise sessions . Laboratory Evaluations Cardiorespiratory fitness was assessed by using a maximal exercise test that followed a modified version of Balke and Ware 's protocol ( 18 ) . Briefly , the test began with the participant walking on a horizontal treadmill at 88 m/min . After the first minute , the elevation increased to 2 % , and it further increased 1 % each minute up to 25 minutes . For the few patients who were still able to continue , the elevation was held constant after 25 minutes and the speed increased to 5.4 m/min until the participant reached volitional fatigue . Exercise test performance with this protocol correlates highly with measured maximal oxygen uptake ( r=0.92 ) ( 19 ) . Serum sample s were analyzed by using automated techniques in a laboratory that participates in and meets the quality control st and ards of the Centers for Disease Control and Prevention Lipid St and ardization Program . Blood pressure was measured by auscultatory methods with a mercury sphygmomanometer according to American Heart Association guidelines ( 20 ) . The lowest of three blood pressure measurements at the clinic examination was recorded as the baseline blood pressure . Height and weight were measured by using a st and ard beam-balance scale and stadiometer , and body mass index was calculated . Type 2 Diabetes Diabetes was defined according to criteria of the American Diabetes Association : fasting plasma glucose level of 7.0 mmol/L or greater ( 126 mg/dL ) ( 21 ) . Three hundred seventy patients who did not meet this criterion but who gave a history of physician-diagnosed diabetes were considered to have diabetes . Patients were classified as having known diabetes or unknown diabetes according to their diabetes status before the baseline Cooper Clinic examination . Definition of Exposure Variables The principal exposure variables used in our analyses were  cardiorespiratory fitness and self-reported physical activity .  These exposures were determined at the baseline examination . Cardiorespiratory Fitness  We categorized  total time from the maximal exercise test into frequency distributions for specific age groups ( 30 to 39 , 40 to 49 , 50 to 59 , and 60 years ) . The least fit 20 % of the participants in each age group were classified as low fit , the next 40 % of the distribution as moderately fit , and the highest 40 % as high fit . We have used these cut-points to define fitness in previous studies ( 12 , 13 ) , and they are based on our entire cohort rather than on diabetic patients only . We selected these cut-points before undertaking the current analysis . Cardiorespiratory fitness is expressed as maximal metabolic units ( METs ) attained during the exercise test . The METs are calculated as the working metabolic rate divided by the resting metabolic rate , and 1 MET is equivalent to an oxygen uptake of 3.5 mL1 kg 1 . Physical Activity Patients who reported walking , jogging , or participating in aerobic exercise programs in the 3 months before the examination were classified as active , regardless of the frequency and duration of exercise . Otherwise , patients were classified as inactive . In our cohort , more than 76 % of men who reported being active at baseline still reported being active at the second visit after more than 1 year . In comparison , only 34 % of men who reported being inactive at baseline reported being active at the second examination ( P<0.001 ) . Self-reported physical activity status in our cohort is correlated with maximal exercise test performance ( 6 , 22 ) . Baseline or Parental Cardiovascular Disease We defined baseline cardiovascular disease as a personal history of heart attack , stroke , or a revascularization procedure ; an abnormal resting or exercise electrocardiogram ; or the highest heart rate during exercise testing that was less than 85 % of the age-predicted maximal heart rate ( [ 220 age in years ] 0.85 ) . Men who reported a history of cardiovascular disease in either parent were classified as having parental cardiovascular disease . Conventional Cardiovascular Disease Risk Factors We assigned men to risk strata for conventional cardiovascular disease risk factors on the basis of recent recommendations ( 23 ) . We defined high blood pressure as systolic blood pressure of 140 mm Hg or more , diastolic blood pressure of 90 mm Hg or more , or a history of physician-diagnosed hypertension . We classified participants with a total cholesterol level of 6.2 mmol/L ( 240 mg/dL ) or more as having high cholesterol , those with self-reported current smoking as current smokers , those with a self-reported parental history of myocardial infa rct ion or stroke as having a history of parental cardiovascular disease , those with a body mass index less than 25.0 kg/m2 as normal weight , and those with a body mass index of 25.0 kg/m2 or more as overweight . Statistical Analysis Our primary outcome measure was all-cause mortality . We used the National Death Index to identify  decedents in the ACLS . The National Death Index has been shown to be an effective , accurate means of ascertaining deaths in the general population , with a sensitivity of about 96 % and a specificity of 100 % ( 24 ) . We obtained official death certificates from states in which there were ACLS decedents , and we had the certificates coded by a nosologist according to the International Classification of Diseases , Ninth Revision . Only the underlying cause of death was used in analyses for this report . Data were analyzed by using the SAS statistical package ( SAS Institute , Inc. , Cary , North Carolina ) . The analyses assumed that physical activity and fitness were essentially unchanged during the study period . We used survival curves to estimate survival function against time and log [ log ( survival time ) ] to check the proportional hazards model assumption . Log [ log ( survival function ) ] estimates were approximately parallel across exposure Purpose Following colorectal cancer diagnosis and anti-cancer therapy , declines in cardiorespiratory fitness and body composition lead to significant increases in morbidity and mortality . There is increasing interest within the field of exercise oncology surrounding potential strategies to remediate these adverse outcomes . This study compared 4 weeks of moderate-intensity exercise ( MIE ) and high-intensity exercise ( HIE ) training on peak oxygen consumption ( V̇O2peak ) and body composition in colorectal cancer survivors . Methods Forty seven post-treatment colorectal cancer survivors ( HIE = 27 months post-treatment ; MIE = 38 months post-treatment ) were r and omised to either HIE [ 85–95 % peak heart rate ( HRpeak ) ] or MIE ( 70 % HRpeak ) in equivalence with current physical activity guidelines and completed 12 training sessions over 4 weeks . Results HIE was superior to MIE in improving absolute ( p = 0.016 ) and relative ( p = 0.021 ) V̇O2peak . Absolute ( + 0.28 L.min−1 , p < 0.001 ) and relative ( + 3.5 ml.kg−1.min−1 , p < 0.001 ) V̇O2 peak were increased in the HIE group but not the MIE group following training . HIE led to significant increases in lean mass ( + 0.72 kg , p = 0.002 ) and decreases in fat mass ( −0.74 kg , p < 0.001 ) and fat percentage ( −1.0 % , p < 0.001 ) , whereas no changes were observed for the MIE group . There were no severe adverse events . Conclusions In response to short-term training , HIE is a safe , feasible and efficacious intervention that offers clinical ly meaningful improvements in cardiorespiratory fitness and body composition for colorectal cancer survivors . Implication s for Cancer SurvivorsHIE appears to offer superior improvements in cardiorespiratory fitness and body composition in comparison to current physical activity recommendations for colorectal cancer survivors and therefore may be an effective clinical utility following treatment AIM To evaluate the effect of regular aerobic exercise on the endothelial function and cardiorespiratory fitness in pregnant women . METHOD This was a r and omized , double-blinded , controlled clinical trial of 64 healthy primigravid women between 16 and 20 weeks ' gestation . The experimental group took part in aerobic exercise at an intensity of 50 - 65 % of their maximum heart rate for 60 min , three times a week for 16 weeks . The control group undertook their usual physical activity . The outcomes were the endothelial function evaluated by flow-mediated dilatation and cardiorespiratory fitness evaluated by the maximum indirect oxygen consumption ( VO2max ) in a 6-min walk test . RESULTS Initially , no differences were found between the groups in any of the variables . At the end of the intervention , the participants that performed exercise showed a higher cardiorespiratory fitness , measured by the walked distance in the 6-min walk test ( P = 0.014 ) and by the VO2max ( P = 0.014 ) . Also , the exercise group showed a lower heart rate at rest and a higher flow-mediated dilatation than the control group ( P = 0.02 ) . CONCLUSIONS Regular aerobic exercise improves endothelium-dependent vasodilation in pregnancy . This intervention may be an early and effective alternative to strengthen the prevention of disorders associated to endothelial dysfunction BACKGROUND Cardiovascular diseases are the leading cause of death globally and sedentary lifestyle is one of the main risk factors . Home-based cardiac rehabilitation ( CR ) programs appear to be effective to improve exercise tolerance . The aim of the study , therefore , was to evaluate the effects of a phase IV ( maintenance ) home-based CR program on cardiorespiratory fitness and daily physical activity of patients recovering from an acute myocardial infa rct ion . METHODS This pilot study , with a sub-group r and omised controlled trial , included 32 individuals recovering from a myocardial infa rct ion , r and omly divided into the experimental group ( EG , n=16 ) and the control group ( CG , n=16 ) . The EG performed an exercise program , three times per week , at home during eight weeks . The two groups received health education sessions . Baseline and final assessment s included cardiorespiratory fitness , resting and peak heart rate , blood pressure and rate pressure , heart rate recovery and daily physical activity . ( Clinical Trials.gov : NCT01887080 ) . RESULTS At baseline no significant differences were observed between groups . After eight weeks of exercise , the EG significantly increased peak oxygen uptake ( p=0.02 ) , test duration ( p=0.019 ) , peak rate pressure ( p=0.003 ) , peak heart rate ( p=0.003 ) and heart rate recovery ( 0.025 ) when compared to the CG . No changes were observed on daily physical activity in both groups . CONCLUSION This specific phase IV home-based exercise program seems to improve cardiorespiratory fitness , haemodynamics at peak exercise and heart rate recovery , an indicator of cardiac autonomic function OBJECTIVES To determine whether cardiorespiratory fitness at baseline is associated with maintenance of cognitive function over 6 years or with level of cognitive function on tests performed 6 years later in a longitudinal study of healthy older people . DESIGN Prospect i ve cohort . SETTING Community-based study of noninstitutionalized adults aged 55 and older living in Sonoma , California . PARTICIPANTS Three hundred forty-nine cohort members without evidence of cardiovascular disease , musculoskeletal disability , or cognitive impairment at baseline . MEASUREMENTS Cardiorespiratory fitness measures were based on a st and ard treadmill exercise test protocol and included peak oxygen consumption ( peak VO2 ) , treadmill exercise duration , and oxygen uptake efficiency slope ( OUES ) . Cognitive function was evaluated at baseline with a modified Mini-Mental State Examination ( mMMSE ) and after 6 years of follow-up with a detailed cognitive test battery that included the full MMSE , three tests of attention/executive function , two measures of verbal memory , and two tests of verbal fluency . RESULTS Participants with worse cardiorespiratory fitness at baseline experienced greater decline on the mMMSE over 6 years ( mean mMMSE decline ( 95 % confidence interval ) by baseline peak VO2 tertile : lowest = -0.5 ( -0.8 to -0.3 ) , middle = -0.2 ( -0.5 - 0.0 ) , highest = 0.0 ( -0.3 - 0.2 ) , P = .002 for trend over tertiles ) . Participants with worse baseline cardiorespiratory fitness also performed worse on all cognitive tests conducted 6 years later . Results were similar for analyses based on peak VO2 , treadmill exercise duration , and OUES . After adjustment for demographic and health-related covariates , measures of cardiorespiratory fitness were associated most strongly with measures of global cognitive function and attention/executive function . CONCLUSION Baseline measures of cardiorespiratory fitness are positively associated with preservation of cognitive function over a 6-year period and with levels of performance on cognitive tests conducted 6 years later in healthy older adults . High cardiorespiratory fitness may protect against cognitive dysfunction in older people OBJECTIVE To examine and evaluate improvements in cardiorespiratory fitness , psychological wellbeing , quality of life , and vocational status in postmyocardial infa rct ion patients during and after a comprehensive 12 month exercise rehabilitation programme . SUBJECTS The sample population comprised 124 patients with a clinical diagnosis of myocardial infa rct ion ( 122 men and two women ) . INTERVENTIONS 62 patients were r and omly allocated to a regular weekly aerobic training programme , three times a week for 12 months , and compared with 62 matched controls who did not receive any formal exercise training . A five year follow up question naire/interview was subsequently conducted on this population to determine selected vocational/lifestyle changes . RESULTS Significant improvements in cardiorespiratory fitness ( p < 0.01 - 0.001 ) , psychological profiles ( p < 0.05 - 0.001 ) , and quality of life scores ( p < 0.001 ) were recorded in the treatment population when compared with their matched controls . Although there were no significant differences in mortality , a larger percentage of the regular exercisers resumed full time employment and they returned to work earlier than the controls . Controls took lighter jobs , lost more time from work , and suffered more non-fatal reinfa rct ions ( p < 0.05 - 0.01 ) . CONCLUSIONS Regularly supervised and prolonged aerobic exercise training improves cardiorespiratory fitness , psychological status , and quality of life . The trained population also had a reduction in morbidity following myocardial infa rct ion , and significant improvement in vocational status over a five year follow up period The objective of this study was to examine exercise effects on global brain volume , hippocampal volume , and cortical thickness in schizophrenia patients and healthy controls . Irrespective of diagnosis and intervention , associations between brain changes and cardiorespiratory fitness improvement were examined . Sixty-three schizophrenia patients and fifty-five healthy controls participated in this r and omised controlled trial .  Global brain volumes , hippocampal volume , and cortical thickness were estimated from 3-Tesla MRI scans . Cardiorespiratory fitness was assessed with a cardiopulmonary ergometer test . Subjects were assigned exercise therapy or occupational therapy ( patients ) and exercise therapy or life-as-usual ( healthy controls ) for six months 2h weekly . Exercise therapy effects were analysed for subjects who were compliant at least 50 % of sessions offered . Significantly smaller baseline cerebral ( grey ) matter , and larger third ventricle volumes , and thinner cortex in most areas of the brain were found in patients versus controls . Exercise therapy did not affect global brain and hippocampal volume or cortical thickness in patients and controls . Cardiorespiratory fitness improvement was related to increased cerebral matter volume and lateral and third ventricle volume decrease in patients and to thickening in the left hemisphere in large areas of the frontal , temporal and cingulate cortex irrespective of diagnosis . One to 2h of exercise therapy did not elicit significant brain volume changes in patients or controls . However , cardiorespiratory fitness improvement attenuated brain volume changes in schizophrenia  patients and increased thickness in large areas of the left cortex in both schizophrenia patients and healthy controls BACKGROUND The cardiorespiratory fitness of stroke survivors is low . Center-based exercise programs that include an aerobic component have been shown to improve poststroke cardiorespiratory fitness . This pilot study aims to determine the feasibility , safety , and preliminary efficacy of an individually tailored home- and community-based exercise program to improve cardiorespiratory fitness and walking capacity in stroke survivors . METHODS Independently ambulant , community-dwelling stroke survivors were recruited . The control  ( n = 10 ) and intervention ( n = 10 ) groups both received usual care . In addition the intervention group undertook a 12-week , individually tailored , home- and community-based exercise program , including once-weekly telephone or e-mail support . Assessment s were conducted at baseline and at 12 weeks . Feasibility was determined by retention and program participation , and safety by adverse events . Efficacy measures included change in cardiorespiratory fitness ( peak oxygen consumption [ VO2peak ] ) and distance walked during the Six-Minute Walk Test ( 6MWT ) . Analysis of covariance was used for data analysis . RESULTS All participants completed the study with no adverse events . All intervention participants reported undertaking their prescribed program . VO2peak improved more in the intervention group ( 1.17 ± .29 L/min to 1.35 ± .33 L/min ) than the control group ( 1.24 ± .23 L/min to 1.24 ± .33 L/min , between-group difference = .18 L/min , 95 % confidence interval [ CI ] : .01-.36 ) . Distance walked improved more in the intervention group ( 427 ± 123 m to 494 ± 67 m ) compared to the control group ( 456 ± 101 m to 470 ± 106 m , between-group difference = 45 m , 95 % CI : .3 - 90 ) . CONCLUSIONS Our individually tailored approach with once-weekly telephone or e-mail support was feasible and effective in selected stroke survivors . The 16 % greater improvement in VO2peak during the 6MWT achieved in the intervention versus control group is comparable to improvements attained in supervised , center-based programs BACKGROUND Studies relating physical exercises and health have contributed to eluci date the influence of sedentary habits on the incidence of cardiovascular diseases . OBJECTIVE To compare the effect of different intensities of aerobic exercises on  patients ' functional capacity ( VO₂(peak ) ) and quality of life after acute myocardial infa rct ion . METHODS Eighty-seven men ( 57.7 ± 6.1 years old ) were enrolled in this prospect i ve study and assigned to one of three groups : a ) high-intensity physical training ( n=29 ) at 85 % maximum heart rate for 12 weeks ; b ) moderate-intensity training ( n=29 ) at 75 % maximum heart rate for 12 weeks ; and c ) control group ( n=29 ) , who were followed . The training groups did aerobic exercises five times a week in 45-minute sessions , besides muscular strengthening and stretching exercises  . Maximum VO₂ was measured through a cardiopulmonary test , and quality of life was assessed through the MacNew Question naire . RESULTS Two-way ANOVA revealed a significant increase in VO₂(peak ) ( p<0.05 ) in the high-intensity training group ( from 29.9 ± 2.2 ml/kg.min to 41.6± 3.9 ml/kg.min ) compared with the moderate-intensity training group ( from 32.0 ± 5.3 ml/kg.min to 37.1 ± 3.9 ml/kg.min ) . Additionally , both training groups showed a significant increase in this parameter compared with the control group ( from 31.6 ± 3.9 ml/kg.min to 29.2 ±4.1 ml/kg.min ) . Quality of life improved significantly ( p<0.05 ) in the high-intensity training group ( from 5.66 to 6.80 ) and in the moderate-intensity training group ( from 5.38 to 6.72 ) , but not in the control group ( from 5.30 to 5.15 ) . CONCLUSION Exercises of greater intensity result ed in an increase in functional capacity and quality of life in patients after myocardial infa rct ion 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 This study was design ed to investigate the effect of exercise intensity on cardiorespiratory fitness and coronary heart disease risk factors . Maximum oxygen consumption ( Vo(2 max ) ) , lipid , lipoprotein , and fibrinogen concentrations were measured in 64 previously sedentary men before r and om allocation to a nonexercise control group , a moderate-intensity exercise group ( three 400-kcal sessions per week at 60 % of Vo(2 max ) ) , or a high-intensity exercise group ( three 400-kcal sessions per week at 80 % of Vo(2 max ) ) . Subjects were instructed to maintain their normal dietary habits , and training heart rates were represcribed after monthly fitness tests . Forty-two men finished the study . After 24 wk , Vo(2 max ) increased by 0.38 + /- 0.14 l/min in the moderate-intensity group and by 0.55 + /- 0.27 l/min in the high-intensity group . Repeated- measures analysis of variance identified a significant interaction between monthly Vo(2 max ) score and exercise group ( F = 3.37 , P < 0.05 ) , indicating that Vo(2 max ) responded differently to moderate- and high-intensity exercise . Trend analysis showed that total cholesterol , low-density lipoprotein cholesterol , non-high-density lipoprotein cholesterol , and fibrinogen concentrations changed favorably across control , moderate-intensity , and high-intensity groups . However , significant changes in total cholesterol ( -0.55 + /- 0.81 mmol/l ) , low-density lipoprotein cholesterol ( -0.52 + /- 0.80 mmol/l ) , and non-high-density lipoprotein cholesterol ( -0.54 + /- 0.86 mmol/l ) were only observed in the high-intensity group ( all P < 0.05 vs. controls ) . These data suggest that high-intensity training is more effective in improving cardiorespiratory fitness than moderate-intensity training of equal energy cost . These data also suggest that changes in coronary heart disease risk factors are influenced by exercise intensity Epidemiological studies suggest a dose-response relationship exists between physical activity and cognitive outcomes . However , no direct data from r and omized trials exists to support these indirect observations . The purpose of this study was to explore the possible relationship of aerobic exercise dose on cognition .  Underactive or sedentary participants without cognitive impairment were r and omized to one of four groups : no-change control , 75 , 150 , and 225 minutes per week of moderate-intensity semi-supervised aerobic exercise for 26-weeks in a community setting . Cognitive outcomes were latent residual scores derived from a battery of 16 cognitive tests : Verbal Memory , Visuospatial Processing , Simple Attention , Set Maintenance and Shifting , and Reasoning . Other outcome measures were cardiorespiratory fitness ( peak oxygen consumption ) and measures of function functional health . In intent-to-treat ( ITT ) analyses ( n = 101 ) , cardiorespiratory fitness increased and perceived disability decreased in a dose-dependent manner across the 4 groups . No other exercise-related effects were observed in ITT analyses . Analyses restricted to individuals who exercised per- protocol ( n = 77 ) demonstrated that Simple Attention improved equivalently across all exercise groups compared to controls and a dose-response relationship was present for Visuospatial Processing . A clear dose-response relationship exists between exercise and cardiorespiratory fitness . Cognitive benefits were apparent at low doses with possible increased benefits in visuospatial function at higher doses but only in those who adhered to the exercise protocol . An individual ’s cardiorespiratory fitness response was a better predictor of cognitive gains than exercise dose ( i.e. , duration ) and thus maximizing an individual ’s cardiorespiratory fitness may be an important therapeutic target for achieving cognitive benefits . Trial Registration Clinical Trials.gov OBJECTIVE This study investigated the effect of commuter cycling on cardiorespiratory fitness in men and women . Secondary outcomes included body fat and blood pressure measurements . METHODS In February 2009 , 48 volunteers from the Isl and of Funen , Denmark were r and omly assigned to either " no change in lifestyle " or to " minimum 20 minutes of daily commuter cycling during 8 weeks " . Maximal oxygen uptake was assessed directly during a progressive cycle-ergometer-test , sum of skinfolds was used as an estimate of body fat , and  blood pressure was measured using a Dinamap monitor . Measurements were obtained at baseline and at the conclusion of the 8-week intervention program . RESULTS Six cyclists dropped out . After 8 weeks VO(2)max ( mL O(2 ) min(-1 ) ) and cardiorespiratory fitness ( mL O(2 ) kg(-1 ) min(-1 ) ) were significantly improved in the cycling group when compared to the control group . Delta change in VO(2)max between groups equaled 206 mL O(2 ) min(-1 ) ( p=0.005 ) and delta change in cardiorespiratory fitness equaled 2.6 mL O(2 ) kg(-1 ) min(-1 ) ( p=0.003 ) . Body fatness changed more noticeable ( p=0.026 ) in the cyclists ( -12.3±7.3 mm ) than in the controls ( -0.2±7.1 mm ) . CONCLUSIONS VO(2)max and cardiorespiratory fitness were significantly improved and body fat reduced as a result of people engaging in 8 weeks of commuter cycling OBJECTIVE It is unknown if aerobic exercise overloads or improves the cardiovascular system among workers with high occupational physical activity . This was investigated in a worksite r and omized controlled trial ( RCT ) of aerobic exercise among cleaners . METHODS We r and omized 116 cleaners between 18 - 65 years . The aerobic exercise group ( N=57 ) performed worksite aerobic exercise ( 30 minutes twice a week ) and the reference group ( N=59 ) received lectures .  Cardiorespiratory fitness , blood pressure ( BP ) and diurnal heart rate ( HR ) for measuring aerobic workload [ % HR reserve ( % HRR ) ] were collected at baseline and after four months . A repeated measure 2 × 2 multi-adjusted mixed-model design was applied to compare the between-group differences in an intention-to-treat analysis . RESULTS Between-group differences ( P<0.01 ) were found : cardiorespiratory fitness 2.2 [ st and ard error ( SE ) 0.8 ] ml O 2 × min -1 × kg -1 [ 95 % confidence interval ( 95 % CI ) 0.6 - 3.8 ] , aerobic workload - 3.5 ( SE 1.2 ) % HRR ( 95 % CI - 5.9- -1.0 ) , resting HR -3.8 ( SE 1.2 ) bpm ( 95 % CI -6.1- - 1.4 ) , sleeping HR -3.8 ( SE 1.1 ) bpm ( 95 % CI - 5.9- - 1.7 ) , and systolic BP 3.6 ( SE 1.3 ) mmHg ( 95 % CI 1.1 - 6.0 ) . CONCLUSIONS Worksite aerobic exercise seems to improve cardiorespiratory fitness , aerobic workload , and resting and sleeping HR , but increase systolic BP among cleaners . Beneficial physiological cardiovascular effects are seen from aerobic exercise , but also a harmful effect is evident . Therefore , recommendations should take into consideration the potential cardiovascular overload from additional aerobic exercise on workers with high levels of occupational physical activity Inconsistencies exist in the assessment and interpretation of peak VO2 in the pediatric obese population , as cardiorespiratory fitness assessment s are effort-dependent and psychological variables prevalent in this population must be addressed . This study examined the effect of a peer modeling intervention on cardiorespiratory fitness performance and task self-efficacy in obese youth completing a maximal treadmill test . Forty-nine obese ( BMI ≥ 95th percentile for age and sex ) youth were r and omized to an experimental ( received an intervention ) or to a control group . The outcome variables were mean and variability cardiorespiratory fitness ( peak VO2 , heart rate , duration , respiratory exchange ratio ) , rating of perceived exertion , and task self-efficacy scores . Irrespective of whether a mean or variability score was used , receiving the intervention was associated with non-significant trends in fitness parameters and task self-efficacy over time , favoring the experimental group . Cardiorespiratory fitness and task self-efficacy were moderately correlated at both time points . To eluci date the aforementioned findings , psychosocial factors affecting obese youth and opportunities to modify the peer modeling intervention should be considered . Addressing these factors has the potential to improve st and ard of care in a clinical setting regarding pretest patient education BACKGROUND Physical activity has been advocated as an important factor in the primary prevention of non-insulin-dependent diabetes mellitus ( NIDDM ) , but information concerning the specific intensities and duration s that are protective has been unavailable . OBJECTIVE To examine prospect ively the association between self-reported levels of the intensity and duration of physical activities  , and cardiorespiratory fitness ( assessed by  respiratory gas exchange )  and incident cases of NIDDM ( assessed by the oral glucose tolerance test ) in a population -based sample of 897 middle-aged Finnish men . RESULTS After adjustment for age , baseline glucose values , body mass index , serum triglyceride levels , parental history of diabetes , and alcohol consumption , moderately intense physical activities ( > or = 5.5 metabolic units ) that were undertaken for at least a 40-minute duration per week were associated with a reduced risk of NIDDM ( odds ration [ OR ] , 0.44 ; 95 % confidence interval [ CI ] , 0.22 - 0.88 ) . Activities with less than an intensity of 5.5 metabolic units , regardless of their duration , were not protective . Cardiorespiratory fitness levels greater than 31.0 mL of oxygen per kilogram per minute were protective against NIDDM ( OR , 0.26 ; 95 % CI , 0.08 - 0.82 ) . A subgroup of men at high risk of NIDDM , because they were overweight and were hypertensive and had a positive parental history of NIDDM , who engaged in moderately intense physical activities above the 40-min/wk duration reduced their risk of NIDDM by 64 % compared with men who did not participate in such activities . CONCLUSIONS After adjustment for age , baseline glucose levels , and known risk factors , physical activities with an intensity of 5.5 metabolic units or greater and a duration of 40 minutes or greater per week protected against the development of NIDDM . These protective effects were even more pronounced in a subgroup of men who were at high risk for the development of the disease We report here the design and baseline data from Project Active , a 2-yr r and omized trial design ed to compare the effectiveness of a Lifestyle physical activity intervention with the traditional Structured exercise prescription approach . Primary outcome measures are energy expenditure in physical activity ( estimated by kcal per kilogram of body weight of energy expenditure ) and cardiorespiratory fitness ( measured by maximal oxygen uptake ) . The participants , 235 initially sedentary and apparently healthy adults , were r and omized into either the Lifestyle or Structured intervention groups . The Lifestyle treatment consists of a personalized approach that accounts for an individual 's motivational readiness and preferences for integrating physical activity into daily routines . The Structured approach is the familiar exercise prescription that is based on a frequency , intensity , and duration formula . The primary hypothesis to be tested is that there will be a difference in physical activity and cardiorespiratory fitness measures between the two conditions at the end of 24 months . The secondary hypothesis is that both groups will make significant improvements from baseline in physical activity and cardiorespiratory fitness at the end of 6 months . Six months of active intervention are followed by 18 months of a tapered follow-up maintenance intervention in both groups . Primary outcome measures are measured after 6 and 24 months
Conclusions Workplace-based physical activity interventions consisting of at least moderate-intensity activity improve cardiorespiratory fitness .
At the present time , we surmise that no single group of employees ( e.g. older employees or less fit individuals ) can be definitively identified as st and ing to benefit more from workplace physical activity interventions than others .
This demonstrates the potential utility of workplace physical activity interventions for improving cardiorespiratory fitness in a broad range of healthy employees .
Background Cardiorespiratory fitness is a strong predictor of all-cause mortality .
Physical activity of at least moderate intensity can improve cardiorespiratory fitness .
Workplaces may provide a relatively controlled setting in which to improve cardiorespiratory fitness through physical activity .
Limited work has been conducted to quantify the impact of delivering physical activity in the workplace on cardiorespiratory fitness .
Objective The objective of this systematic review was to quantify the effects of workplace physical activity interventions on peak oxygen consumption ( VO2peak ) and explore study and participant characteristics as putative moderators .