Velocity-Based Training: Signal vs. Noise

This is an R workbook. I am using my older bench press data, in which I want to discuss Signal vs. Noise of Velocity-Based Training (VBT) measurements. This could be used for future reliability studies. The goal is to compare within-individual variations of velocity over the load-velocity relationship (noise) with the smallest practical velocity difference (in my opinion difference in velocities across nRM, e.g. 4RM – 5RM) which could be called signal

Data

I have saved some of my old data in .CSV file (originaly published at GymAware website). The data represents mean velocity (MV) of bench press (sets of 1 rep) at 4 intensity levels (40, 60, 80 and 100kg), performed for three sets each (with 3sec pause on the chest). N = 1 (the author)

We can create a simple Load-Velocity linear model, but what we are interested in are residuals (how much each point differs from the model – in this case, LV line). We will use residual standard error (note: I will use RMSE – root mean square error)