If I keep try to keep accurate records, such as doing a certain weight for 4 reps (i.e, 80 seconds), I tend to start getting sloppy in my form just so I can lift that weight longer or use a heavier weight for the same number of reps. I seem to get a “better” workout if I just pick a weight that I can lift for somewhere between 1 and 2 minutes and just concentrate on lifting it with the best form I can until I cannot lift it anymore. This way I just concentrate on working the muscle and not on beating my lift from before.
Some workouts I use a weight that I can do for about a minute, and other workouts I use a lighter weight that takes more like 2 minutes. I do keep mental notes on how much I lifted before so I know in general I’m increasing over time, but I find it hard to do every workout without sacrificing form. How do you keep accurate records without sacrificing form?
Part of the reason many High Intensity Training and SuperSlow instructors switched from counting reps to recording time under load (TUL) was the belief it would encourage subjects to move more slowly and reduce or eliminate certain form discrepancies. While people do tend to move more slowly overall when being timed rather than counting reps there is a tendency to rush through harder portions of the range of motion while “sand bagging” in the easier portions to increase set duration.
In both cases the problem is focusing on the measurement – reps or TUL – rather than the real objective of efficiently inroading the target muscles and working them as intensely as possible. The solution is to not count a repetition or subtract it’s duration from the total TUL if you don’t perform it well. You’ll be less tempted to loosen your form or cheat on a rep when you know it won’t count or be added to your time if you do.