It has been suggested that children are less likely than adults to demonstrate a plateau in oxygen uptake (V02) at maximal exercise. However, there has been no direct comparison. Therefore, the purpose of this study was to compare boys and men in achievement of plateau as well as the secondary criteria for maximal effort: heart rate (HR), respiratory exchange ratio (RER), and blood lactate (BLa). Seventeen boys (10.7 ±v 0.6 yrs) and 21 men (22.5 ± 2.0 yrs) completed a practice exercise test and a graded exercise test in order to determine VO2max and achievement of the criteria. The men also completed a second graded exercise test at a faster speed to determine if speed may affect plateau achievement. Comparisons indicated that, except for the BLa criterion, men and boys have similar rates of achievement. In addition, speed does not seem to play a role in criteria achievement. However, due to a small sample size, these results should be viewed with caution. / School of Physical Education

The purpose of this study was to examine if measurements of submaximal blood lactate may improve the prediction of VO2max from submaximal exercise tests. Subjects (39 men & 21 women, age 20-44 yrs) completed a branching protocol on a cycle ergometer which consisted of 3 submaximal stages of 4 minutes each followed by a maximal effort. During the last minute of each stage heart rate (HR) was recorded from telemetry and a capillary blood sample was obtained from a finger puncture. Maximal power output was estimated from the extrapolation of the 3 submaximal HRs to age predicted HRmax and blood lactate concentration was measured using a Yellow Springs analyzer (Yellow Springs, OH). Data were analyzed using multiple regression procedures. Estimated maximal power output (238 ± 56 W) was significantly related to measured VOzmaX (p < 0.001, r2= .523). Mean values for ACSM estimated, ACSM-revised and measured VOz.X were not significantly different (3.170 vs. 3.140 vs. 3.260 L/min respectively), however the SEE % for the ACSM and ACSM revised estimated VOz,. were 13.4% and 12.1%, respectively. When the change in power output relative to the change in blood lactate concentrations (po/BL) from stage 1 to stage 2 and the estimated maximal power output from 3 submaximal heart rates were added as independent variables to the regression model with measured VO2,t as the dependent variable, po/BL was significantly correlated with VO X , accounting for 7.6% of the variance in VOz... In conclusion, only the relative change in power output to the relative change in blood lactate measure from stage 1 to _2 were significant in improving the estimation of VO2 during submaximal exercise tests using a branching protocol. Other blood lactate measures did not improve the estimation of VOA,. in this study. / School of Physical Education

The purpose of this study was to describe mathematically the oxygen uptake kinetics during cycle ergometry, and to examine the effect of intensity on the kinetic responses within the severe domain. Sixteen volunteers performed a series of exercise tests at a range of intensities selected to elicit fatigue in ~3 to 10 min. A simple mono-exponential model effectively described the response across all intensities. There was a positive correlation between the response time and the time to fatigue, demonstrating that the maximal oxygen uptake was achieved faster at higher intensities within the severe domain. Models incorporating two components effectively described the responses only in tests lasting 8 min or more. It was concluded that there is a second, slow component in the oxygen uptake response only at the lower intensities within the severe domain.

The purpose of this study was to determine the validity of the Ebbeling one-stage submaximal treadmill protocol to estimate maximal oxygen uptake in overweight males and females. Forty-five male and females (36.5±10.9 years; 170.2±9.9 cm; 77.9±9.0 kg) were categorized into overweight groups using a BMI of 25-29.9 kg/m2. The subjects performed a submaximal protocol that consisted of one 4-minute stage with individualized speeds of 2.0-4.5 mph at 5% grade and subsequently performed a maximal exercise test. There were significant relationships between observed and estimated VO2max for males (r=.796), females (r=.426), and gender combined (r=.844). There was an underestimation in the estimation of VO2max in the present study when comparing males (10%), females (26%) and gender combined (17%) subjects. The results indicated that a body mass index between the values of 25-29.9 kg/m2 did create a difference in estimating VO2max in the present study when comparing that to Ebbeling et al. (1991).Ball State UniversityMuncie, IN 47306 / School of Physical Education

The direct measurement of maximal oxygen consumption (V02 max) has always been the benchmark for the determination of Cardiorespiratory fitness (CRF). However, the time and expense of that type of testing does not lend itself to students in activity classes or adult fitness participants. Therefore, the purpose of this study was to evaluate the validity of a 500 yard shallow water run test in determining CRF. A commonly used field test, the 1.5 mile run, was used as a basis for comparison during the 500 yard water run. Subjects in this study included 15 men and 28 women that completed a 1.5 mile run and a 500 yard shallow water run as well as a graded exercise test to fatigue on a treadmill. Correlations between 1.5 mile runs and the 500 yard shallow water run and VO2 peak were -.89 and -.80 respectively. In addition to simple regression analysis, multiple regression analysis was used to significantly improve the prediction of CRF (p<0.05). Peak HR during the 1.5 mile run significantly improved the 1.5 mile run prediction of CRF (R2=0.78 to 0.82) with a reduction in SEE (3.95 to 3.52 ml/kg/min) from the simple regression alone. Percent body fat and subject height improved the 500 yard shallow water runs prediction of CRF (R2=0.62 to 0.86) with a reduction in SEE (5.14 to 3.19 ml/kg/min). In conclusion the 500 yard shallow water run can be used to accurately predict CRF and with the addition of percent body fat and height provide a better prediction of CRF. / School of Physical Education