prt.RdData 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.
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.
Data frame prt was obtained by merging
prt.subjects and prt.fiber.
summary(prt)
#> id prt.f age.f sex.f bmi
#> 15 : 48 High:1228 Young:1172 Female:1359 Min. :18.37
#> 50 : 46 Low :1243 Old :1299 Male :1112 1st Qu.:23.00
#> 25 : 44 Median :24.77
#> 95 : 44 Mean :24.94
#> 10 : 43 3rd Qu.:26.96
#> 5 : 41 Max. :32.29
#> (Other):2205
#> iso.fo spec.fo occ.f fiber.f
#> Min. :0.1600 Min. : 80.5 Pre:1228 Type 1:1299
#> 1st Qu.:0.6490 1st Qu.:135.3 Pos:1243 Type 2:1172
#> Median :0.8280 Median :155.2
#> Mean :0.8783 Mean :157.2
#> 3rd Qu.:1.0430 3rd Qu.:176.4
#> Max. :2.5650 Max. :290.0
#>