Home Current Issue Previous Issues Published Ahead-of-Print Collections For Authors Journal Info
Skip Navigation LinksHome > November 1997 - Volume 29 - Issue 11 > Relationships between TriTrac-R3D vectors, heart rate, and s...
Medicine & Science in Sports & Exercise:
Special Communications: Methods

Relationships between TriTrac-R3D vectors, heart rate, and self-report in obese children

COLEMAN, KAREN J.; SAELENS, BRIAN E.; WIEDRICH-SMITH, MARGO D.; FINN, JEREMY D.; EPSTEIN, LEONARD H.

Collapse Box

Abstract

The TriTrac (Professional Products, Inc., Madison, WI) triaxial accelerometer and diary self report were compared with adjusted heart rates to evaluate 3 d of leisure-time activity in 35 8- to 12-yr-old obese children. Adjusted heart rates were calculated by subtracting preexercise resting heart rates from heart rates measured in the field. TriTrac and self-reported data were converted to multiples of resting metabolic rate (METs). Correlations between accelerometer METs and adjusted heart rates (r = 0.71) were significantly higher (P < 0.001) than correlations between adjusted heart rates and self-reported METs (r = 0.36) or accelerometer and self-reported METs (r = 0.38). Self-reported METs had higher mean standard errors in estimating heart rates (13.93 ± 6.15 beats·min-1) than did accelerometer METs (10.94 ± 5.62 beats·min-1; P < 0.001), were significantly greater than accelerometer METs (2.50 ± 1.48 vs 1.80 ± 1.48; P< 0.05) and systematically overestimated accelerometer METs. The anteroposterior vector accounted for 36%, and the vector magnitude score accounted for 34% of the variance in unadjusted heart rates. The mediolateral vector and vector magnitude score accounted for 69% of the variance in self-reported METs. The vertical vector did not account for variance in either unadjusted heart rates or self-reported METs. It was concluded that the TriTrac yielded a better estimate of activity in obese children than self report. In addition, the vector magnitude composite score of the TriTrac accounted for significantly more variance in both self-reported activity and unadjusted heart rates as compared with the vertical directional vector of the TriTrac.

©1997The American College of Sports Medicine

Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us