Setvio guide
Velocity-Based Training (VBT): Bar Speed and Velocity Loss
Velocity-based training (VBT) uses the speed of the bar to guide strength training. Bar speed drops in a predictable way as a load gets closer to your maximum, so it tells you how heavy a weight is for you today, and how much your reps slow down within a set tells you how much fatigue you are building up.
Why bar speed shows how heavy a load is
In a study of 120 strength-trained men in the bench press, the relationship between relative load (% of 1RM) and bar velocity was almost perfect (R² = 0.98). After six weeks of training their 1RM rose by 9.3%, yet the velocity at each percentage stayed the same. A true maximum moved at 0.16 m/s on average (González-Badillo & Sánchez-Medina, 2010). So a given speed corresponds to roughly the same percentage of your maximum, whatever that maximum is today.
Mean, peak and propulsive velocity
- Mean velocity: the average speed of the lifting phase of a rep. The most common measure.
- Peak velocity: the fastest instant of the rep. Useful for explosive lifts, but more variable.
- Mean propulsive velocity: the average of only the part where the bar is being accelerated. Some studies and devices report it, and with light loads it reads higher than mean velocity, so always compare the same measure.
Velocity loss: fatigue within a set
Velocity loss is how much slower your reps get during a set, compared with the fastest rep. It tracks fatigue closely: in the bench press and the squat it correlated with blood lactate at r = 0.93 to 0.97 (Sánchez-Medina & González-Badillo, 2011). That's why many VBT programs end each set at a velocity-loss threshold instead of at a fixed number of reps.
| Velocity loss | Result |
|---|---|
| 20% | The same strength gains with 40% fewer reps, and a larger jump improvement: 9.5% against 3.5% |
| 40% | More growth of the vastus lateralis and intermedius, two of the quadriceps muscles |
The table summarizes Pareja-Blanco et al., 2017. A meta-analysis of the training studies drew the same picture: the velocity-loss limit made no difference to strength, higher limits favored muscle growth, and lower limits favored jumping, sprinting and speed with submaximal loads (Jukic et al., 2023).
Load-velocity profile and 1RM from velocity
Film several loads of the same lift in one session and you can draw a line between load and speed. Extend that line to the speed at which a true maximum ends, and the load where they meet is an estimate of your 1RM: that's the load-velocity profile.
It's an estimate, not a max test. In the squat, the speed of a true maximum varied a lot from day to day, and the predicted 1RMs differed from the real ones (Banyard et al., 2017). In the deadlift, every prediction overestimated the real 1RM (Ruf et al., 2018). Use it to follow trends, not to pick a weight you have never lifted.
Do you need a sensor?
VBT used to require a linear transducer attached to the bar. Phone apps can now measure bar speed from video: one iPhone app agreed closely with a linear transducer in the bench press (Balsalobre-Fernández et al., 2018). Each app and device measures in its own way, so compare your readings with your own earlier sets rather than with another device's numbers. For a full review of the method, see Weakley et al., 2021.
How to measure bar velocity in Setvio
For phone placement, plate calibration and checking a measurement, follow the Android phone bar-speed tutorial.
- In the session editor, on a barbell exercise, tap Measure with video.
- Choose the Plate size on the bar, then tap the centre of the plate and its edge. The plate's known diameter sets the scale.
- Prop the phone up to the side of the bar, facing the plate, frame the bar and press Record. Do the set and stop the recording.
- Check the detected reps, discard any false one and tap Use these numbers. Setvio fills in the mean and peak velocity, the range of motion and the tempo, and shows the velocity loss.
The video is processed on your phone and never saved. In Tracking, tapping a session shows its mean velocity and velocity loss. If you film at least three clearly different loads of the bench press or squat in one session, Tracking also shows your Load-velocity profile with a 1RM from velocity. Setvio doesn't estimate it for the deadlift, and for the squat it uses different thresholds for men and women, so set your Biological sex in Settings.
Setvio is not a laboratory instrument: its video measurement has been checked against simulated motion, not against a linear transducer. Use it to compare your own sets with each other.
Published by Qjason Mobile, the developer of Setvio. Sources are listed below; app examples use demonstration data.
Sources
- González-Badillo JJ, Sánchez-Medina L. Movement velocity as a measure of loading intensity in resistance training. Int J Sports Med. 2010;31(5):347-52. doi.org/10.1055/s-0030-1248333
- Sánchez-Medina L, González-Badillo JJ. Velocity loss as an indicator of neuromuscular fatigue during resistance training. Med Sci Sports Exerc. 2011;43(9):1725-34. doi.org/10.1249/MSS.0b013e318213f880
- Pareja-Blanco F, Rodríguez-Rosell D, Sánchez-Medina L, Sanchis-Moysi J, Dorado C, Mora-Custodio R, et al. Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations. Scand J Med Sci Sports. 2017;27(7):724-735. doi.org/10.1111/sms.12678
- Jukic I, Castilla AP, Ramos AG, Van Hooren B, McGuigan MR, Helms ER. The Acute and Chronic Effects of Implementing Velocity Loss Thresholds During Resistance Training: A Systematic Review, Meta-Analysis, and Critical Evaluation of the Literature. Sports Med. 2023;53(1):177-214. doi.org/10.1007/s40279-022-01754-4
- Banyard HG, Nosaka K, Haff GG. Reliability and Validity of the Load-Velocity Relationship to Predict the 1RM Back Squat. J Strength Cond Res. 2017;31(7):1897-1904. doi.org/10.1519/JSC.0000000000001657
- Ruf L, Chéry C, Taylor KL. Validity and Reliability of the Load-Velocity Relationship to Predict the One-Repetition Maximum in Deadlift. J Strength Cond Res. 2018;32(3):681-689. doi.org/10.1519/JSC.0000000000002369
- Balsalobre-Fernández C, Marchante D, Muñoz-López M, Jiménez SL. Validity and reliability of a novel iPhone app for the measurement of barbell velocity and 1RM on the bench-press exercise. J Sports Sci. 2018;36(1):64-70. doi.org/10.1080/02640414.2017.1280610
- Weakley J, Mann B, Banyard H, McLaren S, Scott T, Garcia-Ramos A. Velocity-Based Training: From Theory to Application. Strength Cond J. 2021;43(2):31-49. doi.org/10.1519/SSC.0000000000000560