There are three popular forms of training: RPE-RIR, VBT, and PBT. Of those, the oldest by far is PBT. VBT and RPE-RIR are forms of autoregulation, which means they are adaptable for each day of training.

PBT entails completing a 1RM or estimated 1RM, then following a program that (usually) progresses upward in the % of 1RM across a training cycle. For example, you may do 3x12-15 @ 70% 1RM, 3x8-12 @ 80% 1RM, and then 3x2-4 at 90% 1RM each week, respectively. If you had a bad day during the pre-test 1RM or accumulated too much fatigue during testing, loading based on percentage 1RM could lead to an inappropriate stimulus during training (Zourdos et al., 2016). Furthermore, the number of repetitions which can be performed at the same percentage of 1RM can differ substantially between athletes based on genetic differences and training background (Richens and Cleather, 2014). Lastly, as maximal strength has been shown to fluctuate daily due to fatigue, and significantly increase due to continuous training, the method of prescribing relative load on potentially obsolete 1-RMs has been questioned. The one major benefit of PBT is it generally pushes you to hit your numbers, which can be motivating, especially for strength athletes.

RPE-RIR uses a number between 1-10 to prescribe repetitions remaining in a set. For example, an RPE-RIR of 8 would mean you have two reps left before failure. Research has reported that most people can estimate RIR accurately (within ~1 repetition) during the leg and chest press exercises when sets are performed within 0–3 repetitions from failure (Hackett et al., 2017). RIR-based RPE have also been strongly and inversely correlated with velocity for both the squat (r = −0.87, p < 0.001) and bench press (r = −0.79, p < 0.001; Helms et al., 2017b), the idea being that as movement velocity decreases with higher intensities, reported RPE increases (RIR decreases).

VBT is a program regulated based on the movement speed during the training. This training program relies on a device to detect bar speed. Different training purposes require various speeds. For example, a speed below 0.5 m/s is considered effective to develop maximum strength. During the training, if the movement speed exceeds the speed range, the load will be increased; otherwise, the load will be reduced or the training will be terminated. You can use VBT to stop a set by indicating a percentage of velocity loss. Another example: once your velocity decreases by ~20% from the first rep of your first set you call it quits for the exercise that day.

VBT vs PBT

Recent research has shown that the use of VBT within a resistance trained population had similar adaptations in 1RM for back squat, bench press, and overhead press, compared to traditional PBT. The VBT had two advantages in this comparison: they completed less overall volume and also improved vertical jump height more than the PBT group, which could be a result of the lower overall volume.

VBT vs RPE-RIR

These two have not been compared much, but a recent study indicated that both methods  cause positive adaptations in participant strength and power qualities. However, the extent of this improvement differed according to the method used with objective autoregulation, making use of movement velocity for feedback, resulting in larger and more certain improvements in strength and power tests than subjective autoregulation.

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