Maximal Graded Exercise Treadmill Test Research Articles

A Comparison of the Validity of Three Exercise Tests for Estimating Maximal Oxygen Uptake in Korean Adults Aged 19–64 Years

The purpose of this study was to compare the validity of three submaximal exercise tests (SMETs) and develop practical predictive models for the VO2max in Korean adults. A total of 541 (287 males and 254 females) adults participated in this study. Their ages ranged from 19 to 64. The VO2max was measured using the maximal-graded exercise treadmill test. The SMETs were performed by a treadmill test, the YMCA step test, and the PACER test. Regression analysis was conducted to compare the validity of the VO2max predictive equations using SMETs. The validity of the predictive models was evaluated using explanatory power, standard error of estimate (SEE), and Bland-Altman analysis. The explanatory power between the measured VO2max and the predicted VO2max was 58.0% (<0.001), 59.2% (<0.001), and 71.7% (<0.001), respectively. The SEEs were 4.545, 4.478, and 3.732 (mL/kg/min). The models were significant predictors of VO2max and had acceptable validity in a large sample of Korean adults. Especially, among the predictive models, PACER had the highest acceptable effectiveness. Therefore, the equations developed in this study are recommended to better evaluate the cardiovascular endurance of Korean adults.

Seasonal changes in wildland firefighter fitness and body composition

Hiking with a pack is the highest-intensity task that wildland firefighters (WLFFs) perform during sustained activities related to wildland fire suppression. Firefighters perform this and other tasks together as a crew; this provides a unique model to evaluate select physical and physiological changes in members of working crews over a fire season during extended operations. The objective of this study was to evaluate changes in peak aerobic fitness (VO2peak), sustainable aerobic fitness at the ventilatory threshold (VO2vt) and body composition over a 5-month wildland fire season. WLFFs from four crews (55 males, 10 females) participated in a maximal graded exercise treadmill test and body composition evaluation pre- and post season. VO2peak values and variance did not change across the fire season (pre=3.96±0.65, post=3.96±0.69Lmin−1, not significant). VO2vt average decreased slightly while variance decreased greatly within each crew (pre=37.5±7.0, post=35.4±2.3mLkg−1 min−1, P<0.05). There was an improvement in VO2vt in initially less-fit WLFFs and a VO2vt decrease in initially more-fit WLFFs. WLFFs lost fat mass (−1.56±−1.06kg, P<0.01) and fat-free mass (−0.38±−1.24kg, P<0.05). Post-season VO2vt values were the same as the higher range of the documented metabolic cost of uphill load carriage and reveal a unique group adaptation to extended physical demands.

Individualized Relative-Intensity Physical Activity Accelerometer Cut Points.

Physical activity (PA) intensity is expressed as either absolute or relative intensity. Absolute intensity refers to the energy required to perform an activity. Relative intensity refers to a level of effort that takes into account how hard an individual is working relative to their maximum capacity. We sought to develop methods for obtaining individualized relative-intensity accelerometer cut points using data from a maximal graded exercise treadmill test (GXT) so that each individual has their own cut point. A total of 2363 men and women 38 to 50 yr old from the CARDIA fitness study wore ActiGraph 7164 accelerometers during a maximal GXT and for seven consecutive days in 2005-2006. Using mixed-effects regression models, we regressed accelerometer counts on heart rate as a percentage of maximum (%HRmax) and on RPE. Based on these two models, we obtained a moderate-intensity (%HRmax = 64% or RPE = 12) count cut point that is specific to each participant. We applied these subject-specific cut points to the available CARDIA accelerometer data. Using RPE, the mean moderate-intensity accelerometer cut point was 4004 (SD = 1120) counts per minute. On average, cut points were higher for men (4189 counts per minute) versus women (3865 counts per minute) and were higher for Whites (4088 counts per minute) versus African Americans (3896 counts per minute). Cut points were correlated with body mass index (rho = -0.11) and GXT duration (rho = 0.33). Mean daily minutes of absolute- and relative-intensity moderate to vigorous PA were 34.1 (SD = 31.1) min·d and 9.1 (SD = 18.2) min·d, respectively. RPE cut points were higher than those based on %HRmax. This is likely due to some participants ending the GXT before achieving their HRmax. Accelerometer-based relative-intensity PA may be a useful measure of intensity relative to maximal capacity.

Study on Validation of 20 m Progressive Aerobic Cardiovascular Endurance Run and Estimation of Maximal Oxygen Uptake in Adolescents

PURPOSE The purpose of this study was to investigate the validity of the 20 m PACER and to develop accurate and practical prediction models of maximal oxygen consumption using 20 m PACER. METHODS In total 407 (male 207, female 200) in middle and high school students participated in this study. Maximal oxygen uptake was measured using the maximal-graded exercise treadmill test. Sex, age, and anthropometrics variable were measured as potential predictors. Each test was conducted within a week interval, ensuring sufficient rest. Correlation analysis was performed to investigate the validity of 20 m PACER. Regression analysis was performed to develop the maximum oxygen uptake prediction equation using the 20 m PACER. The accuracy of prediction models was evaluated using R2, standard error of estimate (SEE), mean difference (MD), and limit of agreement (LoA%) against a criterion-measured of maximal oxygen uptake. RESULTS 20 m PACER was respectively .675 (.001) in male students .585 (.001) in female students showed reasonable validity. The equation of the following was developed (R2=0.77; SEE=3.58): VO2max=53.550+0.169 (20 m PACER)-0.333 (%body fat)+2.276 (sex)-0.080 (height). Gender has a value of 0 for men and 1 for women. CONCLUSIONS The prediction models included 4 variables as significant predictors of maximal oxygen uptake and had acceptable accuracy in a large sample of South Korean adolescent. Therefore, developed equation in this study is recommended for better estimation of cardiopulmonary fitness of middle and high school students. 색인어: 20m 왕복오래달리기, 타당도, 최대산소섭취 량 ì¶”ì •ì‹, í•™ìƒê±´ê°•ì²´ë ¥í‰ê°€ Keywords: 20 m PACER, Validity, Equation of maximal oxygen uptake, PAPS

Prediction of maximal oxygen consumption using the Young Men's Christian Association-step test in Korean adults.

To develop accurate and practical prediction models of maximal oxygen consumption (VO2max) using the Young Men's Christian Association (YMCA)-step test in South Korean adults. In total, 568 adults (20-66years) were included in this study. To develop and cross-validate prediction models of VO2max, the total sample was divided into 80% training and 20% testing using a simple random sampling method. VO2max was measured using the maximal-graded exercise treadmill test. Sex, age, 1-min recovery heart rate, body weight, and height were measured as potential predictors. Each test was conducted within a 2- to 3-day interval, ensuring sufficient rest. Preliminary prediction models were developed from training datasets, which were cross-validated using regression analyses and/or repeated-measures analysis of variance. The accuracy of prediction models was evaluated using R2, standard error of estimate (SEE), and mean difference (MD) against a criterion-measured VO2max. The average age and VO2max were 43.5 ± 12.9years and 39.1 ± 7.5ml/kg/min, respectively. For model development, three practical models with acceptable accuracy were developed (R2 = 0.56-0.61; SEE = 4.74-5.01). For model cross-validation, significant relationships between the criterion-measured and predicted VO2max were observed in all three models (R2 = 0.56-0.61; SEE = 4.62-4.88). The difference between criterion-measured and predicted VO2max was not significant in the models (MD =- 0.03 to - 0.14). The prediction models included 3-5 variables as significant predictors of VO2max and had acceptable accuracy in a large sample of South Korean adults. The selected models provide a simple and practical method to estimate VO2max using the YMCA-step test for South Korean adults.

Heart Rate and Breathing Rate Response During Maximal Graded Exercise Is Altered After Volitional Breath Training in Healthy Volunteers

PURPOSE: To investigate the effect of 6 weeks supervised pranayamic volitional breath training (PVBT) on heart rate and breathing rate response during maximal graded exercise treadmill test (GXTT) in healthy adult volunteers0. METHODS: Consecutive, consenting healthy adult volunteers of mean age 20.56 ± 2.49 years (n = 30), underwent baseline recording of resting heart rate (HR), blood pressure (BP) and respiratory rate (RR) followed by Bruce ramp protocol maximal GXTT until volitional exhaustion providing total test time (TT), derived VO2max achieved, heart rate and breathing rate response during maximal GXTT and drop in recovery HR data. After six weeks of observation, the participants underwent pre-intervention recording followed by supervised PVBT intervention for 6 weeks, 30 minutes a day for 5 days a week, and post-intervention recording. Repeated measures ANOVA with pairwise t-statistical comparison was used to analyze the data. RESULTS: The participants, after supervised PVBT, showed significant increase in TT (805.993 ± 99.04 vs. 806.00 ± 97.92 vs. 868.97 ± 97.48 seconds, p < 0.001), VO2max (53.37 ± 6.68 vs. 53.47 ± 6.75 vs. 57.77 ± 6.74 ml/kg/min, p < 0.001), and significant difference in the heart rate and breathing rate response during maximal GXTT post intervention, which is represented graphically (Figure 1 and 2). CONCLUSIONS: After supervised PVBT, the participants showed improvement in maximal GXTT performance and altered heart rate and breathing response during exercise probably due to learnt behavior to control the breathing pattern improving the breathing economy, improvement in respiratory muscle aerobic capacity, increase in stroke volume and cardiac output and attenuation of respiratory muscle metaboreflex.

Validation of the step test and exercise prescription tool for adults.

Canadian clinical practice guidelines for the management of diabetes highlight the value of physical activity for improving clinical markers and risk factors for diabetes. The use of tools like the Step Test and Exercise Prescription (STEP) in clinical practice facilitates chronic disease management and prevention through the promotion of healthy physical activity. The validity and reliability of STEP has been established previously for use with adults 65 to 85 years of age. The purpose of this study was to test the validity of the prediction equation for VO₂max from the STEP tool for use with adults older than 65 years. Forty participants completed both the predictive self-paced VO₂max stepping protocol from the STEP tool, and a maximal graded exercise treadmill test with breath-by-breath analysis of expired gases. Tests were completed in random order, and participants rested between tests until blood pressure returned to baseline. The average age of the sample was 43±14 years. There was a strong relationship between predicted VO₂max from STEP and direct measures of VO₂max from the maximal treadmill test in the present study (r=.78, p<0.001). Bland-Altman analysis demonstrated statistical agreement between tests, although there was systematic overestimation of 6.4 mL/kg/min. STEP is an evidence-based cardiorespiratory fitness assessment and exercise prescription tool appropriate for use by various health professionals in clinical practice. The prediction equation for VO₂max from the STEP tool is valid for use with adults 18 to 85 years of age. However, more research is warranted to explore age corrections to the prediction algorithm among younger adults.

Crossvalidation of Two 20-M Shuttle-Run Tests for Predicting V[Combining Dot Above]O2max in Female Collegiate Soccer Players

The aim of this study was twofold: (a) to compare the maximal attained speed (MAS) from the 20-m shuttle (MST) and 20-m square-shuttle (SST) tests and (b) to crossvalidate 2 equations for predicting maximal oxygen consumption (VO2max) that were previously developed from MST and SST in a group of female collegiate soccer players. Thirty-nine subjects (age: 20.1 ± 1.5 years) participated in the study. A maximal graded exercise treadmill test was used to measure VO2max. In addition, VO2max was predicted from the MAS obtained during MST ((pred)VO2maxMST) and SST ((pred)VO2maxSST) using previously developed equations. Measured VO2max for the group was 44.2 ± 3.3 ml·kg(-1)·min(-1). The MAS was 12.5 ± 0.6 km·h(-1) for MST and 13.3 ± 0.8 km·h(-1) for SST (p < 0.05). The prediction methods yielded a (pred)VO2maxMST of 49.6 ± 3.9 ml·kg(-1)·min(-1) and predVO2maxSST of 41.8 ± 3.1 ml·kg(-1)·min(-1), which were significantly different from measured VO2max (p < 0.05). The validity statistics revealed the following constant error (CE), correlation coefficient (r), standard error of estimate (SEE), and total error (TE) for (pred)VO2maxMST and (pred)VO2maxSST: CE = 5.35 ± 3.83, r = 0.45 (p < 0.05), SEE = 2.97 ml·kg(-1)·min(-1), TE = 6.39 ml·kg(-1)·min(-1); and CE = -2.43 ± 2.49, r = 0.69 (p < 0.05), SEE = 2.39 ml·kg(-1)·min(-1), TE = 3.43 ml·kg(-1)·min(-1), respectively. Residual plots indicated no proportional bias for either prediction model. The results of this study suggest that female collegiate soccer players had a higher MAS from SST compared with that from MST. In addition, SST appeared to be a more accurate predictor of VO2max than MST in the group of athletes.

Correlates of Heart Rate Recovery over 20 Years in a Healthy Population Sample

Slow HR recovery (HRR) from a graded exercise treadmill test (GXT) is a marker of impaired parasympathetic reactivation that is associated with elevated mortality. Our objective was to test whether demographic, behavioral, or CHD risk factors during young adulthood were associated with the development of slow HRR. Participants from the Coronary Artery Risk Development in Young Adults study underwent symptom-limited maximal GXT using a modified Balke protocol at baseline (1985-1986) and 20-yr follow-up (2005-2006) examinations. HRR was calculated as the difference between peak HR and HR 2 min after cessation of the GXT. Slow HRR was defined as 2-min HRR <22 beats·min(-1). In 2730 participants who did not have slow HRR at baseline, mean ± SD HRR was 44 ± 11 beats·min(-1) at baseline and declined to 40 ± 12 beats·min(-1) in 2005-2006; slow HRR developed in 5% (n = 135) of the sample by 2005-2006. Female sex, black race, fewer years of education, obesity, cigarette smoking, higher depressive symptoms, higher fasting glucose, hypertension, metabolic syndrome, and physical inactivity and low fitness were each associated with incident slow HRR. In a multivariable model, higher body mass index, larger waist, low education, fasting glucose, and current smoking remained significantly associated with incident slow HRR. Increasing body mass index (per SD higher) during follow-up and incident hypertension, diabetes, and metabolic syndrome (in the subsets of participants who were free from those conditions at baseline) were each associated with significantly elevated odds of incident slow HRR. On average, HRR declines with aging; however, the odds of having slow HRR in early middle age is significantly associated with traditional CHD risk factors.

Aerobic Exercise Improves Cognition for Older Adults with Glucose Intolerance, A Risk Factor for Alzheimer's Disease

Impaired glucose regulation is a defining characteristic of type 2 diabetes mellitus (T2DM) pathology and has been linked to increased risk of cognitive impairment and dementia. Although the benefits of aerobic exercise for physical health are well-documented, exercise effects on cognition have not been examined for older adults with poor glucose regulation associated with prediabetes and early T2DM. Using a randomized controlled design, twenty-eight adults (57-83 y old) meeting 2-h tolerance test criteria for glucose intolerance completed 6 months of aerobic exercise or stretching, which served as the control. The primary cognitive outcomes included measures of executive function (Trails B, Task Switching, Stroop, Self-ordered Pointing Test, and Verbal Fluency). Other outcomes included memory performance (Story Recall, List Learning), measures of cardiorespiratory fitness obtained via maximal-graded exercise treadmill test, glucose disposal during hyperinsulinemic-euglycemic clamp, body fat, and fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulin-like growth factor-1, amyloid-β (Aβ40 and Aβ42). Six months of aerobic exercise improved executive function (MANCOVA, p=0.04), cardiorespiratory fitness (MANOVA, p=0.03), and insulin sensitivity (p=0.05). Across all subjects, 6-month changes in cardiorespiratory fitness and insulin sensitivity were positively correlated (p=0.01). For Aβ42, plasma levels tended to decrease for the aerobic group relative to controls (p=0.07). The results of our study using rigorous controlled methodology suggest a cognition-enhancing effect of aerobic exercise for older glucose intolerant adults. Although replication in a larger sample is needed, our findings potentially have important therapeutic implications for a growing number of adults at increased risk of cognitive decline.

Association of 20-Year Changes in Cardiorespiratory Fitness With Incident Type 2 Diabetes

OBJECTIVETo test the association of fitness changes over 7 and 20 years on the development of diabetes in middle age.RESEARCH DESIGN AND METHODSFitness was determined based on the duration of a maximal graded exercise treadmill test (Balke protocol) at up to three examinations over 20 years from 3,989 black and white men and women from the Coronary Artery Risk Development in Young Adults study. Relative fitness change (percent) was calculated as the difference between baseline and follow-up treadmill duration/baseline treadmill duration. Diabetes was identified as fasting glucose ≥126 mg/dl, postload glucose ≥200 mg/dl, or use of diabetes medications.RESULTSDiabetes developed at a rate of 4 per 1,000 person-years in women (n = 149) and men (n = 122), and lower baseline fitness was associated with a higher incidence of diabetes in all race-sex groups (hazard ratios [HRs] from 1.8 to 2.3). On average, fitness declined 7.6% in women and 9.2% in men over 7 years. The likelihood of developing diabetes increased per SD decrease (19%) from the 7-year population mean change (−8.3%) in women (HR 1.22 [95% CI 1.09–1.39]) and men (1.45 [1.20–1.75]) after adjustment for age, race, smoking, family history of diabetes, baseline fitness, BMI, and fasting glucose. Participants who developed diabetes over 20 years experienced significantly larger declines in relative fitness over 20 years versus those who did not.CONCLUSIONSLow fitness is significantly associated with diabetes incidence and explained in large part by the relationship between fitness and BMI.

Correlates of Heart Rate Recovery in Healthy Young- to Middle-Aged Adults

Slow heart rate recovery (HRR) from a graded exercise treadmill test (GXT) is a marker of impaired parasympathetic reactivation associated with elevated mortality in patients symptomatic for coronary heart disease (CHD). Little is known about changes in HRR over time in adults free from CHD, or about demographic, behavioral, and clinical factors associated with the development of slow HRR. PURPOSE: To describe change in HRR over 20 years, and test the hypothesis that participants with less favorable CHD risk factors during young adulthood are more likely to develop slow HRR over follow-up. METHODS: Participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study who were aged 18 to 30 years in 1985–86 underwent symptom-limited maximal GXT using a modified Balke protocol at the baseline and 20-year (2005-06) examinations. HRR was calculated as the difference between maximum heart rate (HR) and HR 2 minutes following cessation of the GXT in 2,556 participants (56% female, 44% black). Slow HRR was defined as 2-minute HRR < 22 beats/min (bpm). RESULTS: After excluding 56 participants (2.2%) with slow HRR at baseline, mean HRR was 43 bpm (SD = 11). Over 20 years, HRR declined to 39 bpm (SD = 12) and incident slow HRR occurred in 142 participants (5.7%). In a multivariable model adjusting for GXT duration and maximum HR, only low education, smoking, BMI and high blood pressure were significantly associated with incident slow HRR (Table). There were no differences in the incidence of slow HRR by sex and race when GXT performance was taken into account.Table: Multivariable-adjusted baseline characteristics and incident slow HRR over 20 yearsCONCLUSIONS: HRR declines with aging in all asymptomatic adults, but the 20-year incidence of clinically slow HRR is most strongly associated with traditional CHD risk factors.

The temporal relationship between heart rate recovery immediately after exercise and the metabolic syndrome: the CARDIA study

Slower heart rate recovery (HRR) following exercise is associated with the metabolic syndrome, yet the temporal relationship between the two remains unknown. We investigated the cross-sectional and longitudinal associations of slower HRR following a graded exercise treadmill test (GXT) with metabolic syndrome components and LDL-C. Participants aged 18-30 from the Coronary Artery Risk Development in Young Adults study underwent a symptom-limited maximal GXT at baseline (n = 4319) and 7 years later. HRR was calculated as the difference between maximum heart rate (HR) and HR 2 min after test cessation. Slower baseline HRR was associated with a higher cross-sectional level but not longitudinal (15 year follow-up) increases in blood pressure, triglyceride, waist circumference, and LDL-C. No cross-sectional or longitudinal association was observed between HRR and HDL-C. In contrast, participants with one or two or more metabolic syndrome components (National Cholesterol Education Program III and American Diabetes Association criterion) at baseline examination had significantly larger longitudinal declines in HRR [-3.48 (P < 0.05) and-5.64 bpm (P < 0.001), respectively] from baseline to year 7, when compared with participants without syndrome components (-2.40 bpm). Slower HRR does not precede development of the metabolic syndrome, but appears after syndrome components are present.

Physical Activity Recommendations Can Be Met Using A Physically Interactive Video Game Among College Students

Although a plethora of aerobic activities are available for improving fitness, many college students do not accumulate at least 30 minutes or 150 kilocalories of moderate intensity physical activity on a daily basis, as recommended by the American College of Sports Medicine (ACSM). Identifying non-traditional aerobic activities, such as Dance, Dance Revolution (DDR; Konami of America, Inc., Redwood City, CA), a physically interactive video game, may help rectify this trend. PURPOSE To determine if participation in a physically interactive video game that emphasizes lower body movements provides a means for meeting the current physical activity recommendations. METHODS Twenty college students (7 males and 13 females; 24.0±2.6 years; 66.5±3.2 inches; 66.6±16.5 kg; VO2max: 46.2±10.7 ml*kg−1*min−1) volunteered as participants. Each participant completed a maximal graded exercise treadmill test to assess maximal oxygen uptake (VO2max), a treadmill walking protocol at a self-selected “brisk walking pace”, and a session of DDR. Heart rate (HR; Polar heart monitor), rating of perceived exertion (RPE), respiratory exchange rate (RER), oxygen consumption (VO2) via open-circuit indirect calorimetry, total caloric expenditure (TEE30), time to expend 150 kilocalories (T150), average steps per minute (S1.0), total steps (TS30), and rating of overall enjoyment (1 = not enjoyable; 5 = highly enjoyable), were recorded over 30 minutes during the treadmill and DDR sessions. Step counts were recorded using a Yamex 701 pedometer. RESULTS No significant differences were observed between treadmill walking and DDR sessions for exercise RPE (11.1±1.0 vs. 10.7±1.3), RER (0.87±0.04 vs. 0.86±0.04), or T150 (35.9±28.9 vs. 38.4±9.1 minutes). The treadmill walking session compared to DDR, generated significantly higher average exercise HR (113.0±14.2 vs. 105.4±11.3 bpm), VO2 [16.3±2.8 (36.1±6.7% VO2max) vs. 12.3±2.2 (27.3±5.3% VO2max) ml*kg−1*min−1], TEE30 (167.3±56.5 vs. 122.3±27.4 kilocalories), S1.0 (126.7±6.5 vs. 78.0±19.9 steps*min), TS30 (3799.9±195.2 vs. 2339.0±597.1 steps), and TS150 (3724.7±1119.0 vs. 2901.5±746.7 steps) (p < 0.05). A significantly higher level of enjoyment was observed for the DDR (4.1±0.9) compared to treadmill walking (3.1±1.2) (p < 0.05). CONCLUSIONS Although treadmill walking was higher intensity and greater overall energy expenditure, participants reported greater enjoyment and a similar duration to expend 150 kilocalories with DDR. This pilot study suggests that the DDR video game provides an enjoyable alternative to walking for attaining the ACSM recommended daily physical activity for healthy college students.

Physical Activity Recommendations Can Be Met Using A Physically Interactive Video Game Among College Students

Although a plethora of aerobic activities are available for improving fitness, many college students do not accumulate at least 30 minutes or 150 kilocalories of moderate intensity physical activity on a daily basis, as recommended by the American College of Sports Medicine (ACSM). Identifying non-traditional aerobic activities, such as Dance, Dance Revolution (DDR; Konami of America, Inc., Redwood City, CA), a physically interactive video game, may help rectify this trend. PURPOSE To determine if participation in a physically interactive video game that emphasizes lower body movements provides a means for meeting the current physical activity recommendations. METHODS Twenty college students (7 males and 13 females; 24.0±2.6 years; 66.5±3.2 inches; 66.6±16.5 kg; VO2max: 46.2±10.7 ml*kg−1*min−1) volunteered as participants. Each participant completed a maximal graded exercise treadmill test to assess maximal oxygen uptake (VO2max), a treadmill walking protocol at a self-selected “brisk walking pace”, and a session of DDR. Heart rate (HR; Polar heart monitor), rating of perceived exertion (RPE), respiratory exchange rate (RER), oxygen consumption (VO2) via open-circuit indirect calorimetry, total caloric expenditure (TEE30), time to expend 150 kilocalories (T150), average steps per minute (S1.0), total steps (TS30), and rating of overall enjoyment (1 = not enjoyable; 5 = highly enjoyable), were recorded over 30 minutes during the treadmill and DDR sessions. Step counts were recorded using a Yamex 701 pedometer. RESULTS No significant differences were observed between treadmill walking and DDR sessions for exercise RPE (11.1±1.0 vs. 10.7±1.3), RER (0.87±0.04 vs. 0.86±0.04), or T150 (35.9±28.9 vs. 38.4±9.1 minutes). The treadmill walking session compared to DDR, generated significantly higher average exercise HR (113.0±14.2 vs. 105.4±11.3 bpm), VO2 [16.3±2.8 (36.1±6.7% VO2max) vs. 12.3±2.2 (27.3±5.3% VO2max) ml*kg−1*min−1], TEE30 (167.3±56.5 vs. 122.3±27.4 kilocalories), S1.0 (126.7±6.5 vs. 78.0±19.9 steps*min), TS30 (3799.9±195.2 vs. 2339.0±597.1 steps), and TS150 (3724.7±1119.0 vs. 2901.5±746.7 steps) (p < 0.05). A significantly higher level of enjoyment was observed for the DDR (4.1±0.9) compared to treadmill walking (3.1±1.2) (p < 0.05). CONCLUSIONS Although treadmill walking was higher intensity and greater overall energy expenditure, participants reported greater enjoyment and a similar duration to expend 150 kilocalories with DDR. This pilot study suggests that the DDR video game provides an enjoyable alternative to walking for attaining the ACSM recommended daily physical activity for healthy college students.

Energy Expenditure During Physically Interactive Video Game Playing In Male College Students With Different Playing Experience

A previous study has indicated that playing physically interactive video games offers a viable alternative to walking as a means for meeting the American College of Sports Medicine (ACSM) daily physical activity and energy expenditure recommendations. The effect of game playing experience on energy expenditure has yet to be explored. Purpose To determine if playing experience results in different levels of energy expenditure during participation in a physically interactive video game, Dance, Dance Revolution (DDR; Konami of America, Inc., Redwood City, CA). Methods Thirteen male college students volunteered, six experienced DDR players (21.0 + 2.2 years; 71.3+ 2.6 inches; 82.9+ 17.7 kg; VO2max: 49.4+ 10.7 ml*kg-1*min-1) and seven inexperienced (25.6 + 1.6 years; 68.9 + 2.5 inches; 69.2+ 19.3 kg; VO2max: 56.8 + 10.7ml*kg-1*min-1). Experienced players were defined as individuals who regularly and consistently played DDR in the “heavy” mode option whereas inexperienced players opted to play at the “beginner” level. Each participant completed a maximal graded exercise treadmill test to assess maximal oxygen uptake (VO2max), and a session of DDR. Heart rate (HR; Polar heart monitor), rating of perceived exertion (RPE), respiratory exchange rate (RER), oxygen consumption (VO2) via open-circuit indirect calorimetry, total caloric expenditure (TEE30), time to expend 150 kilocalories (T1 50), average steps per minute (S1.0), total steps (TS30), and steps necessary to attain an energy expenditure of 150 kilocalories (TS150), were recorded over 30 minutes during the treadmill and DDR sessions. Step counts were recorded using a Yamex 701 pedometer. Results Compared to inexperienced participants, experienced participants demonstrated significantly higher exercise HR (160.6 + 13.7 vs. 95.5 + 10.4 beats per minute), RPE (14.4 + 1.3 vs. 10.7 + 1.7), RER (0.92 + 0.05 vs. 0.84 + 0.04), VO2 (25.8 + 6.5(52.5 + 9.2%VO2max) vs. 13.1 + 2.2 (23.6 + 4.4% VO2max)ml*kg-1*min-1), TEE30 (307.4+ 56.2 vs. 144.0+28.7kilocalories), S1.0 (108.9 + 11.1 vs. 73.6+ 17.2 steps*min), and TS30 (3267.0 + 334.3 vs. 2207.2 + 514.7 steps) (p < 0.05). Experienced participants also had significantly lower T1 50 and TS150 compared to inexperienced participants (14.8 + 2.8 vs. 32.2 + 7.4 minutes, and 1593.7+ 197.3 vs. 2273.2 + 187.1 steps, respectively) (p < 0.05). Conclusion This pilot study suggests that experienced DDR players expend greater energy during game play, even exceeding ACSM recommendations. This has important implications for individuals interested in using video game play for energy expenditure and possible weight loss or maintenance.

EXERCISE INTENSITY IN RELATION TO HEART RATE RESERVE AND PERCEIVED EXERTION IN TYPE II DIABETIC ADULTS

Exercise training has been recommended in individuals with Type II diabetes for its beneficial effects on glycemic control and cardiovascular disease risk reduction. Percent heart rate reserve (%HRR) and the rating of perceived exertion (RPE) are two widely used methods of assessing physical effort during exercise. Although these measures are considered valid and reliable in healthy adults and some special populations, they have not been validated in adults with Type II diabetes mellitus. PURPOSE To examine the relationships between exercise intensity as measured by percent VO2 peak (%VO2) and both RPE and %HRR in adults with Type II diabetes mellitus. It was hypothesized that RPE and %HRR would be equally highly correlated with %VO2. METHODS Thirteen adults (49.6 ± 12.15 yrs) with duration of diabetes (range 0.5–32.0; mean 9.0 ± 9.66 yrs), completed a maximal graded exercise treadmill test with 2-minute stages to VO2 peak (2.16 ± 0.782 L/min). Rate of perceived exertion using the Borg 6–20 scale was assessed during the last 30s of each stage. Heart rate was monitored continuously via 12-lead ECG and heart rate reserve was calculated. Correlation coefficients were determined between %VO2 and %HRR and between %VO2 and RPE. A test of significant differences was performed between the two correlation coefficients. RESULTS Correlation coefficients of 0.909 and 0.602 were found between %VO2 and %HRR and between %VO2 and RPE, respectively. A t-test of the difference between the correlation coefficients revealed a significantly stronger relationship between %VO2 and %HRR than between %VO2 and RPE, (p < 0.05). CONCLUSION Percent heart rate reserve has a stronger association with exercise intensity than rating of perceived exertion in the Type II diabetic population. Funded by the Indiana University Adult Fitness Program.

INCIDENCE OF HYPERTENSION AMONG WOMEN IN THE AEROBICS CENTER LONGITUDINAL STUDY 510

The relation between cardiorespiratory fitness and hypertension in women is not well-studied. We examined the incidence of hypertension among 3,996 women(age 20-79 y; mean, 43 y) who received a preventive medical examination at the Cooper Clinic in Dallas, Texas, between 1971 and 1995. All participants were apparently healthy (no heart attack, cancer, diabetes, hypertension, or stroke) and normotensive (<140/<90 mmHg) at baseline. All participants performed a maximal graded exercise treadmill test at baseline and responded to a mailback survey in 1982, 1986, 1990 or 1995. Incident cases of physician-diagnosed hypertension (n = 217) were identified by self-report on the mailback surveys. After adjustment for age at survey, year of examination, cigarette smoking, and alcohol consumption, multiple logistic regression analysis showed that each one minute increase in treadmill time was associated with a 10% reduction (p<0.001, 95% confidence interval 6-13%) in risk of hypertension. This association was somewhat attenuated after further adjustment for body mass index and resting systolic blood pressure, but did remain significant (p<0.002). These results suggest that the risk of developing hypertension among women is reduced with higher levels of cardiorespiratory fitness.

Comparison of standard- and extended-length participation in cardiac rehabilitation on body composition, functional capacity, and blood lipids

Participation in a standard-length outpatient cardiac rehabilitation program (CRP) for 3 months is known to result in positive changes in body composition, functional capacity, and blood lipids in patients with coronary artery disease. However, there has been little attempt to compare patients who remain active in a formal CRP for an extended length of >1 year with patients who exit after a standard length of 3 months. Consequently, 50 patients underwent a series of tests including a maximal graded exercise treadmill test, assessment of body composition, and fasting blood lipid analysis, at entry to CRP and after a follow-up period that ranged from 1 to 5 years. All patients participated in a standard multidisciplinary cardiac rehabilitation program for 3 months. Twenty-five patients discontinued participation after 3 months and received no other contact from the program staff until follow-up, whereas 25 patients remained active in the program until follow-up. After statistically adjusting for baseline differences between the groups, significant differences were observed between the extended- and standardlength groups at follow-up for body weight (177 vs 183 lbs), percent fat (22% vs 24%), METS (10.5 vs 8.4), high-density lipoprotein level cholesterol (44 vs 39 mg/dl), total cholesterol/high-density lipoprotein ratio (5.2 vs 6.1), and triglycerides (134 vs 204 mg/dl), respectively. No significant differences in the adjusted means were observed between the groups at followup for total cholesterol (209 vs 219 mg/dl) and lowdensity lipoprotein cholesterol (136 vs 138 mg/dl). Data from this study demonstrate the efficacy of extended participation in CRP on body composition, functional capacity, and blood lipids. Greater efforts need to be directed at retaining patients in low-cost, center-based maintenance programs and at extending monitoring of patients exiting standard length CRPs.