Actual Versus Predicted VO2max: A Comparison of 4 Different Methods

ABSTRACT Measuring expired gases (EGs) while performing a maximal (max) effort exercise test is considered the most accurate evaluation of VO2 max. This methodology is not applicable for all populations. Submaximal (sub-max) protocols not measuring expired gases are more applicable, however their ability to accurately predict VO2max is not clear. PURPOSE: To compare VO2max results from 1) University of Houston Non-Exercise Test (UHNET), 2) McArdle Step Test (MST), 3) Bruce Protocol measuring EGs to max (Bruce-EGs), and 4) Bruce Protocol using time to max (Bruce-TM). METHODS: Recreationally active men and women {n= 24 (16M/8W); age = 25±7.7 years; body mass = 74.5±10.9kg; BMI = 24.3±2.9} completed 4 tests (on the same day) in the following order: 1) UHNET, 2) MST, 3) Bruce-EGs, and 4) Bruce-TM. For the UHNET, participants rated his/her physical activity (PAR). This was followed with a specified equation to estimate the participants VO2 max based on their PAR, age, BMI, and gender. Upon completion of the UHNET, participants performed the MST. The MST required participants to step on a 16.25inch bench at a specific cadence (different for men and women) for 3 minutes. Five seconds following the MST, radial pulse (RP) was assessed for 15 seconds. The radial pulse was converted to HR (beats/min) using the formula (RP*4). To estimate VO2max from the MST, the HR value was applied to a specific equation (different for men and women). Ten minutes after completing the MST, participants performed the Bruce protocol to max. For the Bruce Protocol, VO2max was calculated via 1) measurement of EGs and 2) the time it took to achieve max (TM). Expired gases were measured using a metabolic cart (Parvo Medics TrueOne 2400). To estimate VO2max using TM, the Bruce Protocol Time Formula (different for men and women) was applied. In addition to EGs and TM, HRmax, and Respiratory Exchange Ratio (RER) were assessed. Significant differences (p2 (Bruce-EGs) and estimated VO2 (UHNET, MST, and Bruce-TM) were determined using a one-way repeated measures ANOVA. Pearson correlations and liner regression were performed to determine the relationship between the estimated and actual VO2, as well as, determine how well the estimated VO2 predicted the actual VO2. RESULTS: For the Bruce protocol, HRmax=192±10.1bpm; RER=1.2±0.1, and TM=11.29±1.5 min. For the MST, the average HR was 144±23.3bpm. The actual VO2 (46.3±9.4 ml•kg-1•min -1) was similar to the estimated VO2 from UHNET (45.7±5.6 ml•kg-1•min-1) (p=.67) and MST (47.7±10.1 ml•kg-1•min-1) (p=.32). However, the VO2 obtained from the Bruce-TM (42.3±6.7 ml•kg-1•min-1) was significantly lower (p2 . Significant correlations (p2 and all predicted VO2 values. Liner regression equations expressed an R2 of .38, .61, and .65 for UHNET, MST, and Bruce-TM, respectively. CONCLUSION: Bruce-TM provided the most accurate estimation of the actual VO2max. The MST was slightly less predictive of VO2max though still a valid predictor. The results of this study suggest that to accurately predict VO2max, individuals will need to achieve max effort but might not need to have EGs analyzed. The MST results suggest that estimating VO2max on individuals who do not achieve max effort is still a valid option though might not be as accurate as when achieving max effort. These results should be taken with caution. This study was limited by 1) a small sample size, 2) evaluated only 2 modes of exercise, 3) a potential bias due to non-randomized trials, and 4) evaluated only healthy, active individuals. Increasing the sample size, comparing more methodologies, and randomizing the trials could strengthen the validity of any future investigations

PENGGUNAAN TES LAPANGAN 1,6 KM METODA ROCKPORT UNTUK PENGUKURAN KEBUGARAN JANTUNG-PARU DENGAN BAKU EMAS TREADMILL METODA BRUCE

Kebugaran jantung paru merupakan komponen kebugaran jasmani utama yang menunjang aktivitas fisik harian. Dalam pengukuran kebugaran jantung paru sebagai baku emasnya adalah treadmill diagnostik yang menggunakan Tes Treadmill metoda Bruce (tes Bruce). Di Indonesia belum semua pusat kebugaran menggunakan tes Bruce dalam mengukur kebugaran. Hal tersebut oleh karena mahalnya biaya operasional dan tenaga yang kompeten dalam melaksanakannya. Oleh karena itu diperlukan tes lain yang lebih efisien sehingga masyarakat awampun dapat mengukur tingkat kebugaran jasmani, diantaranya tes lapangan metoda Rockport. Tes Rockport merupakan tes jalan dan atau lari sepanjang 1,6 Km tanpa berhenti.Tes Rockport sudah disosialisasikan Kementerian Kesehatan ke Puskesmas- Puskesmas dan digunakan dalam mengukur kebugaran jantung paru, namun sampai saat ini belum diketahui validitas dari tes tersebut. Subjek penelitian adalah mahasiswa Ilmu Keolahragaan UPI Bandung usia 18 "“ 25 tahun sebanyak 110 orang. Survey analitik digunakan untuk validasi VO2 Max hasil tes rockport terhadap VO2 Max hasil tes bruce. Validitas data diukur dengan koefisien korelasi Pearson. Reliabilitas diukur dengan metode Alpha Cronbach (agreement) yaitu : Bland Altman Plot serta menghitung persamaan regresi. Dari hasil penelitian ini didapatkan rata "“ rata VO2 Max tes Rockport sebesar 44.94 ml/kg bb/menit dan rata "“ rata VO2 Max tes Bruce 56.18 ml/kg bb/menit, didapatkan hasil koefisien validitas = 0.694 (p < 0.01), yang artinya tes Rockport valid terhadap tes Bruce sebagai baku emas. Sedangkan koefisien reliabilitas = 0.795, tes Rockport reliabel, yang artinya tes Rockport ini mantap, yaitu diulang berapa kalipun hasilnya tetap sama. Begitu juga untuk mengetahui agreement kedua tes Rockport dan Tes Bruce menggunakan Bland Altman Plot didapatkan hanya ada 3 data atau 2.7% yang berada di atas 95% Limit Of Agreement (LOA). Hubungan antara tes Rockport dan tes Bruce didapatkan persamaan garis regresi Bruce = 13.247 + 0.955 Rockport. Kekuatan hubungan Bruce-Rockport dinyatakan dengan koefisien korelasi r Pearson = 0.694 (p < 0.01). Kekuatan hubungan ini sedang ke arah kuat (g) Dengan persamaan regresi ini , maka VO2 Max yang diukur dengan tes Rockport dapat dihasilkan VO2 Max seperti diukur langsung dengan tes Bruce. Kesimpulan : (a) Rata-rata VO2 Max yang diukur dengan metode Rockport adalah 44.94 ml/kg bb/menit dengan kriteria Baik. (b) Rata-rata nilai kebugaran yang diukur dengan metode Bruce adalah 56.18 ml/kg bb/menit dengan kriteria Baik, (c) Data Rockport valid terhadap data Bruce dan pengukuran dengan Rockport "Agree" terhadap Bruce (d) Data Rockport valid terhadap data Bruce dan Tes Rockport reliabel(e) Bruce dan Rockport berhubungan dengan bentuk hubungan persamaan garis regresi linier sederhana , yaitu : Bruce = 13.247 + 0.955 Rockport, (f) Kekuatan hubungan Bruce-Rockport dinyatakan dengan koefisien korelasi r Pearson = 0.694 (p < 0.01). Kekuatan hubungan ini Sedang ke arah Kuat. (g) VO2 Max yang diukur dengan tes Rockport dapat dihasilkan VO2 maks seperti diukur langsung dengan Tes Bruce

riverSedge 1978 v.2 no.2

Leroy Quintana -- Ricardo Sanchez -- Alurista -- Rolando Hinojosa -- Bruce-Novoa -- Tomas M. Calderon -- Max Benavidez -- Pancho Aguila -- Jesus Macias -- Cordelia Candelaria -- Ray Gonzalez -- Abelardo Delgado -- Luis Arturo Ramos -- Angela de Hoyos -- Manuel Francisco Sepulveda El Nune -- Alberto Rios -- Sergio Elizondo -- Patricia De La Fuente -- Mario Garza -- Ricardo D. Aguilar.https://scholarworks.utrgv.edu/riversedge/1005/thumbnail.jp

Effect of gender on P-wave dispersion in asymptomatic populations

Background: Exercise testing is a diagnostic tool for evaluating the induction of stress-induced paroxysmal atrial fibrillation (PAF). Resting P-wave dispersion has been suggested to be greater in males versus females but if used by clinicians, gender difference in response to exercise must be determined. Methods: Sixteen healthy subjects (n=8 male, age: 21±0.3; n=8 female, age: 23±1.4) performed an incremental exercise test using the Bruce protocol. Electrocardiograms were recorded at rest, end-exercise, 1, 3, and 5 mins recovery. P-waves were measured in each lead with the maximum (P-max) and minimum (P-min) P-wave durations and dispersion calculated. Results: There was a significant decrease in P-max from rest to end-exercise in males and females [males, 118.3±7.4 (95%CI: 109.7 to 126.8ms) vs. 97.9±6.2 (89.3 to 106.4ms); females, 109.4±4.5 (100.8 to 117.9ms) vs. 94.3±4.6 (85.7 to 102.8ms); p=0.001 (5.7 to 29.8ms)]. Similarly, for P-min [males, 65.6±5.6 (57.4 to 73.9ms) vs. 50.8±2.7 (42.5 to 59.0ms); females, 58.4±3.3 (50.1 to 66.6ms) vs. 45.6±2.7 (37.4 to 53.9ms); p=0.01 (2.2 to 25.4ms)]. Irrespective of gender there was limited change in P-wave dispersion in response to exercise. Males had a longer P-max versus females during the protocol [109.6±2.3 (105.8 to 113.4ms) vs. 103.6±1.8 (99.8 to 107.4ms); p=0.03] but this was not stage-specific. There was no gender differences in either P-min (p=0.12) or P-wave dispersion (p=0.64) across the protocol or stage-specific. Conclusions: Results from this study indicate that in contrast to P-max and P-min, the P-wave dispersion may not be significantly influenced by the sympathetic nervous system in males and females. Therefore, this study suggests males and females should be evaluated in the same way using the P-wave dispersion for predicting the development of stress-induced PAF at rest and during exercise testing protocols

Senior Law Class Officers

p. 42 from the 1932 Pandora, yearbook of the University of Georgia. Courtesy of the Hargrett Rare Book & Manuscript Library, University of Georgia Libraries Senior Law Class Officers: James Robert Bruce, President; Max Rosenthal, Vice-President; Louis K. Kesser, Secretary; William E. Caldwell, Treasurer; William H. Dooner, Chief Justice of the Honor System Court; William T. Thurmond, Honor Court Representative; Joe Milton Ray, Honor Court Representativ

A study on cardiovascular fitness of male medical students

Background:Cardiovascular fitness has been found to be significantly compromised by obesity, whose prevalence is increasing rapidly. The present study aimed to assess the aerobic exercise performance in terms of maximum aerobic power (VO2 max) of the male students of North Bengal medical college in the age range of 18-22 years.Methods:The subjects were divided into two groups viz. control (N=52) and study (N=43) on the basis of Body Mass Index (BMI) and Waist Circumference (WC), according to the current Indian guidelines for obesity. The VO2 max was compared among the two groups. It was evaluated using the Bruce protocol, and also expressed in terms of ‘Metabolic equivalents’ (MET).  Results:VO2 max exhibited significant negative correlation with BMI (r=0.75, P <0.000) and WC (r=0.72, P <0.000). VO2 max was higher for the normal group compared to the study group, and the mean difference was significantly different [P <0.05(0.000)].  Conclusion:The study thus showed that cardiovascular capacity is compromised by excess adiposity

Burns

PurposeIn burned children, exercise training increases maximal oxygen consumption (VO2 max) and can be combined with the nonspecific beta-blocker propranolol to decrease cardiac work. VO2 max is estimated if indirect calorimetry is not available. We compared measured and estimated VO2 max in severely burned children treated with or without propranolol to determine the suitability of commonly used formulas in these populations.MethodsPatients received propranolol or placebo (control) during acute hospitalization. VO2 max was measured during a modified Bruce treadmill test at discharge and compared to values obtained using the Cooper, Bruce, American College of Sports Medicine, and Porro formulas. Pearson correlations and Bland-Altman analyses were used to compare measured and estimated values.ResultsNinety-nine children (propranolol n=46,control n=53) admitted at our facility between 2003 and 2016 were analyzed. Age at burn (propranolol 12\ub14 years, control 12\ub13 years,p=0.893) and total body surface area burned (propranolol 44\ub115%,control 49\ub114%,p=0.090) were comparable between groups. Measured VO2 max was higher in the propranolol group (25.5\ub16.0 mL/min/kg vs. 22.0\ub14.7 mL/min/kg,p=0.002) and was generally lower than estimated values. Age, sex, inhalation injury, body mass index, exercise time, and maximal speed were predictive of measured VO2 max in the control group. Age, sex, and maximal speed were predictive in the propranolol group. Backward selection yielded the formula [7.63+ 2.16 7 sex(females=0,males=1)+ 0.41 7 age(years)+ 0.15 7 maximal speed(m/min)] (R2=0.6525).ConclusionsPropranolol seems to have beneficial effects on cardiorespiratory capacity in burned children. However, estimated VO2 max with common formulas were too high. The VO2 max formula reported here is suitable for propranolol-treated children and the Porro formula for non-propranolol\u2013treated children.P50 GM060338/GM/NIGMS NIH HHS/United StatesR01 HD049471/HD/NICHD NIH HHS/United StatesT32 GM008256/GM/NIGMS NIH HHS/United StatesU48 DP000043/DP/NCCDPHP CDC HHS/United States2019-12-01T00:00:00Z30005988PMC6289624696

Comparison of High vs. Low Fat Diet Influence on VO2MAX in Adolescent Elite Female Soccer Players

Aerobic fitness relies on ample storage of all macronutrients that come from one’s diet. Dietary recommendations were introduced in the United States in 1977, which have been disputed as to whether a low- or high-fat diet is better for performance. For female athletes, more uncertainty is present due to the lack of research on this population’s dietary guidelines. There is a need for further research comparing high- and low-fat diet influence on the aerobic capacity of adolescent female athletes. This study recruited 30 elite female soccer players, ages 16-18 from Charlotte, NC, who were randomly assigned to either a low- or high-fat diet for 12 months. Each athlete completed the Bruce Treadmill VO2 MAX Test before and after the 12 months to observe the changes in their aerobic capacity. The results were analyzed and compared to determine a correlation between high or low-fat diet and VO2 MAX. PURPOSE: To compare the effect of high- and low-fat diet on VO2 MAX in adolescent elite female soccer players.https://digitalcommons.gardner-webb.edu/exercise-science-research-proposal-posters/1187/thumbnail.jp

Agreement Study Between the ParvoMedics TrueOne 2400 and Vacu-Med Vista MINI-CPX Metabolic Measurement System

Aerobic capacity (VO2 MAX) predicts both athletic performance and health status. Many tools are available to assess VO2 MAX ranging in both cost and accuracy. Understanding limitations of less expensive tools, likely found in settings such as health clinics or sports performance facilities, will help practitioners in developing accurate exercise prescriptions for their respective populations. To evaluate agreement lower cost VO2 MAX assessment tool (Vacu-Med Vista MINI-CPX) to the industry “gold standard” (ParvoMedics TrueOne 2400). Thirty-one participants (22.5 ± 3.5 years; BMI 24.9 ± 2.3; 51% female) completed two sessions of maximal VO2 MAX assessment using the Bruce Protocol graded treadmill exercise test. The first session of assessment utilized the “gold-standard” unit (TrueOne 2400, ParvoMedics, Inc., Murray, UT). 24-48 hours later the second unit (Vista Mini-CPX, Vacu-Med, Inc., Ventura, CA) was used to assess VO2 MAX again. A Bland-Altman analyses was used to evaluate both potential bias and agreement for between the two assessment tools. The CPX unit sig­nificantly overestimated VO2 MAX compared to the TrueOne (Bias = 10.67 ± 5.87 ml/kg/min, LoA = -0.83, 22.18; t = 1.96, p \u3c .001). However, the CPX unit demonstrates good reliability as 93.5% (29/31 participants) of values fell within the 95% LoA. Further, values above 46.5 ml/kg/min tend to be greater than the mean bias while those below tend to be lower than the mean bias (r = .605, F = 16.80, p \u3c .001). The CPX unit demon­strates good reliability yet a significant overestimation of aerobic capacity