prt: prt Data (2471 x 9)

Description Format Details Source See Also Examples


Data from a Progressive Resistance Randomized Trial.


The prt data frame has 2471 rows and 9 columns. It contains data for n = 63 subjects. Each subject underwent muscle biopsy before and after intervention. Data are stored in a long format with each record corresponding to one muscle fiber. There are two types of muscle fibers: Type 1 and Type 2. Dependent variables: specific force and isometric force are measured pre- and post intervention.


a factor with 63 levels 5, 10, 15, 20, 25, ..., 520 (subject id)


a factor with 2 levels High, Low, i.e. training (intervention) intensity


a factor with 2 levels Young, Old (stratifying variable)


a factor with 2 levels Female, Male (stratifying variable)


a numeric vector with values of BMI at baseline ranging from 18.36 to 32.29

a numeric vector with values of isometric force ranging from 0.16 to 2.565

a numeric vector with values of specific force ranging from 80.5 to 290


a factor with 2 levels Pre, Pos, i.e. pre- and post-intervention.


a factor with 2 levels Type 1, Type 2, i.e. Type 1 and Type 2 muscle fiber.


Data frame prt was obtained by merging prt.subjects and prt.fiber.


Claflin, D.R., Larkin, L.M., Cederna, P.S., Horowitz, J.F., Alexander, N.B., Cole, N.M., Galecki, A.T., Chen, S., Nyquist, L.V., Carlson, B.M., Faulkner, J.A., & Ashton-Miller, J.A. (2011) Effects of high- and low-velocity resistance training on the contractile properties of skeletal muscle fibers from young and older humans. Journal of Applied Physiology, 111, 1021-1030.

See Also

prt.fiber, prt.subjects



nlmeU documentation built on May 2, 2019, 3:38 p.m.