R: How to apply moving averages to subset of columns in a data frame?

R: How to apply moving averages to subset of columns in a data frame?

I have a dataframe (training.set) that is 150 observations of 83
variables. I want to transform 82 of those columns with some moving
averages. The problem is the results end up only being 150 numeric values
(i.e. 1 column).
How would I apply the moving average function across each column
individually in the data and keep the 83rd column unchanged? I feel like
this is super simple, but I can't find a solution.
My current code
# apply moving average on training.set data to 82 of 83 rows
library(TTR) #load TTR library for SMA functions
ts.sma <- SMA(training.set[,1:82], n = 10)
ts.sma
Thanks for your help.