TY - JOUR
T1 - Oxygen uptake and ratings of perceived exertion at the lactate threshold and maximal fat oxidation rate in untrained adults
AU - Rynders, Corey A.
AU - Angadi, Siddhartha
AU - Weltman, Nathan Y.
AU - Gaesser, Glenn
AU - Weltman, Arthur
N1 - Funding Information:
Acknowledgments This publication was made possible by the National Institutes of Health grant RR00847. We gratefully acknowledge the contributions of the staff of the General Clinical Research Center at the University of Virginia.
PY - 2011/9
Y1 - 2011/9
N2 - The purpose of the study was to examine the relationship between VO 2 and RPE at the lactate threshold (LT) and maximal fat oxidation rate (FAT MAX) in untrained adults and determine the stability of the relationship across sex, age, and fitness status. A total of 148 untrained adults (mean age [year] = 30.5 ± 13.9, height [m] = 1.72 ± 0.08 m, body mass [kg] = 82.6 ± 20.5, body fat [%] = 28.7 ± 12.0) completed a continuous incremental VO 2 peak/LT protocol. Fat oxidation rates were determined using indirect calorimetry. The highest recorded fat oxidation rate was chosen as FAT MAX. The breakpoint in the VO 2-blood lactate relationship was chosen as LT. RPE was based on the Borg 6-20 scale. Bland-Altman plot analysis demonstrated that VO 2 FAT MAX systematically preceded VO 2 LT (mean bias = 1.3 ml kg -1 min -1) with wide limits of agreement (+9.6 to -6.9 ml kg -1 min -1). Multivariate ANOVA revealed a significant difference between VO 2 FAT MAX (12.7 ± 7.5 ml kg -1 min -1) and VO 2 LT (14.1 ± 5.9 ml kg -1 min -1) in the total sample (p = 0.04). There were no differences between the intensities when the sample was divided into sex, age, and fitness comparison groups (p values[0.05). RPE FAT MAX (9.4 ± 2.5) preceded RPE LT (10.4 ± 2.0) in the total sample (p = 0.008), but was not different across comparison groups (p[0.05). The present data indicate that the highest rate of fat oxidation slightly precedes the LT in untrained adults. For exercise prescription, a Borg-RPE of 9-12 identifies both FAT MAX and LT.
AB - The purpose of the study was to examine the relationship between VO 2 and RPE at the lactate threshold (LT) and maximal fat oxidation rate (FAT MAX) in untrained adults and determine the stability of the relationship across sex, age, and fitness status. A total of 148 untrained adults (mean age [year] = 30.5 ± 13.9, height [m] = 1.72 ± 0.08 m, body mass [kg] = 82.6 ± 20.5, body fat [%] = 28.7 ± 12.0) completed a continuous incremental VO 2 peak/LT protocol. Fat oxidation rates were determined using indirect calorimetry. The highest recorded fat oxidation rate was chosen as FAT MAX. The breakpoint in the VO 2-blood lactate relationship was chosen as LT. RPE was based on the Borg 6-20 scale. Bland-Altman plot analysis demonstrated that VO 2 FAT MAX systematically preceded VO 2 LT (mean bias = 1.3 ml kg -1 min -1) with wide limits of agreement (+9.6 to -6.9 ml kg -1 min -1). Multivariate ANOVA revealed a significant difference between VO 2 FAT MAX (12.7 ± 7.5 ml kg -1 min -1) and VO 2 LT (14.1 ± 5.9 ml kg -1 min -1) in the total sample (p = 0.04). There were no differences between the intensities when the sample was divided into sex, age, and fitness comparison groups (p values[0.05). RPE FAT MAX (9.4 ± 2.5) preceded RPE LT (10.4 ± 2.0) in the total sample (p = 0.008), but was not different across comparison groups (p[0.05). The present data indicate that the highest rate of fat oxidation slightly precedes the LT in untrained adults. For exercise prescription, a Borg-RPE of 9-12 identifies both FAT MAX and LT.
KW - Indirect calorimetry
KW - Lactate threshold
KW - Maximal fat oxidation rate
KW - Physical activity
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U2 - 10.1007/s00421-010-1821-z
DO - 10.1007/s00421-010-1821-z
M3 - Article
C2 - 21259025
AN - SCOPUS:80053930380
SN - 1439-6319
VL - 111
SP - 2063
EP - 2068
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
IS - 9
ER -