Velocity-based training (VBT)

Velocity-based training (VBT) uses measured lifting speed to guide training.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 173.} Rep speeds show whether the load is appropriate, and submaximal lifting speed can estimate a current one rep max (1RM).^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 173.}

Tether-based position transducers, accelerometers and three-dimensional cameras can track speed.^{2Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 145.} Some systems show the client each rep’s numbers immediately.^{3Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 147.} Devices measure different things: a bar-mounted tool records bar velocity, while a force plate records the body and bar together, so their readings may not match.^{4Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 149.}

In practice

• End a set when speed drops too far.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 173.} A coach might stop once velocity falls more than 10 or 20% below the first rep to maintain the intended rep quality.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 173.}
• Use a warm-up set to assess readiness.^{5Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 174.} In one study, a light squat jump was measured before each session; a change of more than 3% from the previous three days meant the day’s loads moved up or down.^{5Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 174.}
• ACSM suggests VBT may suit experienced lifters, while simple progressions such as the 2-for-2 rule can work for novices.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 362.}
• VBT hasn’t been shown to beat a well-designed periodized program run by an attentive coach.^{5Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 174.}