Showing papers by "Patty S. Freedson published in 1991"

Familial Aggregation in Physical Activity

Abstract: The purposes of this study were to (a) examine the stability and consistency of the Caltrac accelerometer (Hemokinetics, Madison, WI) and an activity record to assess physical activity in children and adults (Experiment 1), and (b) to determine if there is a relationship between parents and their children in physical activity level (Experiment 2). Thirty 5–9-year-old children and their biological parents wore Caltrac accelerometers for three consecutive days (including one weekend day). At the same time, parents completed a Caltrac Activity Record (CAL REC) for themselves and their child. Dependent variables were counts per day for the Caltrac and minutes of light activity and activity for the CAL REC. Between-day correlations for the Caltrac ranged from r = .73 to .87 for the parents (p < .001) and from r = .38 (p < .04) to .79 (p < .001) for the children. An analysis of variance with repeated measures indicated no significant differences for the Caltrac between days for parents and children. Be...

Estimation of VO2max: A Comparative Analysis of Five Exercise Tests

Abstract: Thirty-eight female subjects (M ± SD = 33 ± 3.0 years) had VO2max measured on the cycle ergometer (M ± SD = 37.3± 6.4 ml·kg−1·min−1) and on the treadmill (M ± SD = 41.3 + 6.6 ml·kg−1·min−1). VO2max was estimated for each subject from heart rate (HR) at submaximal workloads on the cycle ergometer using the Astrand-Rhyming nomogram (A/R) and the extrapolation method (XTP). VO2max was also estimated from three field tests: 1.5-mile run (RUN) (independent variable [IV] = time), mile walk (WALK) (IV = time, age, HR, gender, body weight), and the Queens College Step Test (ST) (IV = HR during 5–20 s recovery). Repeated measure ANOVA revealed significant mean differences between the criterion cycle ergometer VO2max versus A/R and XTP (20 and 12% overestimation). The WALK, RUN, and ST VO2max values were not significantly different from the criterion treadmill VO2max. The correlation between criterion VO2max and VO2max estimated from the WALK and RUN were r = .73 (SEE = 4.57 ml·kg−1·min−1) and r = .79 (SEE...

Muscle soreness during running - biomechanical and physiological considerations

Abstract: This study involved an 8-day protocol to determine the effects of delayed-onset muscle soreness (DOMS) on the mechanics of the lower extremity and on oxygen consumption during level running. On Day 1 the subjects, 10 healthy female recreational runners, were administered a treadmill max VO2 test. They completed a 30-min downhill run on Day 3 to induce muscle soreness. On Days 2, 5, and 8 they completed a 15-min level run at a speed corresponding to 80% of VO2max. Subsequent to each run the subjects completed a muscle soreness questionnaire and a blood sample was taken for creatine kinase (CK) analysis. Data analysis revealed statistically significant between-day differences for perceived muscle soreness and CK activity. However, metabolic cost was not different between days. There were significant differences between days in maximum ankle support dorsiflexion and plantar flexion and maximum knee flexion during both support and swing. None of the global parameters describing the total stride produced sig...

Effects of coenzyme Q10 supplementation on exercise performance, VO2max, and lipid peroxidation in trained cyclists.

Abstract: The effects of dietary supplementation with Coenzyme Q10 (CoQ10), a reputed performance enhancer and antioxidant, on physiological and biochemical parameters were examined. Ten male bicycle racers performed graded cycle ergometry both before and after being given 100 mg per day CoQ10 or placebo for 8 weeks. Analysis of variance showed a significant difference between groups for postsupplementation serum CoQ10. Although both groups demonstrated training related improvements in all physiological parameters over the course of the study, there were no significant differences between the two groups (p > .05). Both groups showed a 21% increase in serum MDA (an index of lipid peroxidation) after the presupplementation exercise test. After 8 weeks this increase was only 5%, and again was identical for both groups. Supplementation with CoQ10 has no measurable effect on cycling performance, VO2max, submaximal physiological parameters, or lipid peroxidation. However, chronic intense training seems to result in marked attenuation of exercise-induced lipid peroxidation.

Validity of the Caltrac Accelerometer in Estimating Energy Expenditure and Activity in Children and Adults

Abstract: The Caltrac accelerometer functions as either an activity monitor that provides activity counts based on vertical acceleration as the individual moves about, or as a calorie counter in which the acceleration units are used in conjunction with body size, age, and sex to estimate energy expenditure. This study compared VO2 based energy expenditure with Caltrac estimated energy expenditure during three speeds of treadmill walking in children and adults. It also tested the validity of the Caltrac to differentiate between high and low levels of walking activity (activity counts). Ten boys and 10 men completed three randomly assigned walks while oxygen consumption was monitored and Caltrac estimates were obtained. The results indicate that the Caltrac does not accurately predict energy expenditure for boys and men across the three speeds of walking. Although there were no significant differences between actual and predicted energy expenditure values, the standard errors of estimate were high (17-25%) and the on...