Velocity Based Training & the Force Velocity Curve

PerformanceTrack
Written by Cat Hoh

Bar speed tells you how heavy a load is for an athlete today. A percentage of last month's 1RM can't. Lift with full intent and the bar slows in an almost straight line as the load climbs, so three or four warm-up sets on a velocity device give you a profile to program from.

These tools are a guide only. They work from the numbers you enter. They can't see technique, fatigue or how the athlete is feeling, and they don't replace a coach or a properly periodised program. Treat every estimate as a starting point for the session, not a test result.

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Why coaches use bar speed

01Today's load, not last month's

Strength moves from day to day with sleep, training and stress, so a fixed percentage of an old 1RM can be too heavy one week and too light the next. Bar speed tracks relative load, so the target adjusts to the athlete in front of you.

02An estimated max from the warm-up

Three or four warm-up sets give you an estimated 1RM every session, without a fatiguing max test. It's an estimate, off by around 10% on average, so it's for setting training loads, not for testing day.

03Sets that stop at the right point

Ending a set once the bar has slowed by a set amount controls fatigue. In an 8-week squat trial, stopping at 20% loss gave bigger jump gains than 40% loss, with 40% fewer reps.

What you need: a device that measures bar speed (a linear position transducer, a bar-mounted sensor or a validated phone app), set up the same way every session. Every rep has to be lifted as fast as possible. A rep at a comfortable tempo tells you nothing about load.

01

Load-Velocity Calculator

Pick the lift, then enter each warm-up load and the velocity of the fastest rep. The calculator fits a line, extends it down to the speed a true max moves at, and turns that into an estimated 1RM and a load for every target.

How to use it

  1. Warm up through 3 or 4 loads, light to heavy. Start where the bar moves no faster than about 1 m/s and finish near 0.5 m/s or slower.
  2. Do 1 or 2 reps per load as fast as possible, rest fully, and note the velocity of the fastest rep.
  3. Enter each load and velocity. Check the line fit. Below 0.9 usually means one rep wasn't done at full intent.
  4. Pick a target % or a bar speed and load the bar. If the first working rep is clearly slower than the target velocity, the athlete is less ready than the profile says, so take some weight off. Track this set sends the plan to the tracker, and Copy session gives you text to share.

1Your lift

Athlete

Pre-filled with the published group average for the lift. If you've tested this athlete's true max on your device, use their own number. Use the same velocity measure for the max and the warm-ups.

2Your gym

Units
Smallest load jump

Loads round to what your plates can make. Two 1.25 kg plates give a 2.5 kg jump.

3Your warm-up sets

Load (kg)Mean propulsive velocity (m/s)

Use at least two loads, ideally four spread from light to heavy. Blank rows are ignored. Example numbers are loaded; replace them with your athlete's.

4Plan the session

80%
Stop each set at (velocity loss)

Estimated 1RM

--kg, where the line reaches the velocity at 1RMUse it to set loads. Test a true max when you need the exact number.
Line fit (R²)--How neatly the sets sit on one straight line. 1.00 is perfect.
Speed lost per 10 kg--m/sHow quickly this athlete slows as load goes on. Compare it with their own earlier profiles, not with other athletes.

Your load-velocity profile

Solid line through your sets, dashed where it's extended to the estimated max. Background bands are the velocity zones in section 04 (not shown for the power clean).

Your sets Estimated 1RM Target

Today's target

Load--
Bar should move at--m/s, first repYour check on the day. A first rep well below this means the load is heavier for the athlete today than planned.
Velocity zone--What that bar speed mainly trains, using the zones in section 04.

Loads for this athlete

% of est. 1RMLoad (kg)Velocity (m/s)Zone

Loads rounded to the nearest 2.5 kg. Velocities come from this athlete's own line, not a group chart.

How this is worked out

A straight line is fitted through your load and velocity pairs (least squares). The estimated 1RM is the load where that line reaches the velocity at 1RM, the minimal velocity threshold. Each pre-filled threshold is the group average from the study named under the exercise, and every one of them varies by a few hundredths of a m/s between people. A 0.03 m/s error in the threshold moves the estimate by a few percent, which is why an athlete's own tested value beats any group number.

Across 20 studies, this method missed the true 1RM by about 10% on average and tended to overestimate it (Greig et al. 2023). Use it to set training loads, and test directly when you need the real number.

02

Velocity Loss Tracker

The fastest rep comes early. As fatigue builds the bar slows, and how much you let it slow decides what the set trains. Log each rep as it happens and the tracker tells you when to rack it.

How to use it

  1. Choose a cut-off. 20% suits most athletes chasing strength and speed. Go higher only in a block aimed at muscle size.
  2. Lift every rep as fast as possible and enter its velocity straight after. The fastest rep becomes the reference.
  3. Stop when the status turns to Stop the set, even if the athlete has reps left. That's the point.
  4. Tap New set before the next set so it gets its own reference rep. Copy set gives you a summary to paste into your notes.

1Set your cut-off

Velocity loss allowed

Lower cut-offs keep sets fast and fresh. Higher cut-offs push closer to failure. The evidence below explains the trade.

2Log the reps

Press Enter or tap Add rep after each one.

Set status

--
Stop below--m/s, the cut-off for this setFastest rep minus the loss you allowed.
Fastest rep--m/s
Loss so far--from the fastest rep

Rep by rep

The yellow line is the cut-off. Orange bars have crossed it. An example set is loaded; tap New set to start your own.

Read the evidenceHide the evidence

Stopping earlier kept the jump

Pareja-Blanco et al. 2017 gave two groups of young men the same 8-week squat program with the same relative loads. The only difference was when each set ended: once the bar had slowed by 20%, or by 40%.

Figure 01

20% loss against 40% loss, 8 weeks of squats

Jump height

+9.5% vs +3.5%

Countermovement jump improved more in the 20% group.

Work done

40% fewer reps

The 20% group got there with far less total volume.

Squat strength

Similar

1RM gains didn't separate the groups.

Muscle size

40% ahead

More quadriceps growth in the 40% group, along with a loss of the fastest (type IIX) fibres.

Data from Pareja-Blanco et al. 2017. A 2025 trial from the same research group, Sánchez-Valdepeñas et al. 2025, compared 20% and 40% cut-offs with and without blood flow restriction and again found the 20% groups ahead for strength and jump height.

Worth knowing: both trials used the squat and recruited men, and neither measured sprinting or running performance directly. For athletes who need to stay fast, 20% is a sensible default. For a hypertrophy block, letting the bar slow further is a deliberate choice with a cost to speed qualities.
03

The Force-Velocity Curve

Heavy loads move slowly, light loads move fast, and power (force × velocity) peaks in between. Every lift, jump and sprint an athlete does sits somewhere on that line.

Figure 02 / Interactive

Slide along the curve

Force--of max
Velocity--of max
Power0of peak

Schematic. A straight force-velocity line, the model used in jump and squat profiling, with power calculated as force × velocity. On a straight line, power peaks at half of maximum force and half of maximum velocity. Where each exercise sits is approximate and moves from athlete to athlete.

Same power, different athletes

Two athletes can produce the same peak power with very different shapes. One is strong but slow off the mark, the other quick but short of force. Pierre Samozino and Jean-Benoît Morin's jump profiling compares an athlete's line with the one that would maximise their jump, and the gap tells you which end to train.

Figure 03 / Tap to change

Reading an athlete's profile

optimal this athlete VelocityForce
Train force

The line is flatter than optimal: plenty of speed, not enough force. The program leans on heavy strength work, near-maximal squats and loaded jumps at the force end.

this athlete VelocityForce
Train both

The line sits close to optimal. The job is to lift the whole line, so the program mixes heavy, moderate and light, fast work across the curve.

optimal this athlete VelocityForce
Train speed

The line is steeper than optimal: strong, but slow to apply it. The program shifts toward light, fast work: unloaded and assisted jumps, throws and plyometrics.

Schematic. All three athletes have the same peak power. The dashed line is the optimal profile for that power. Line shapes are illustrative, not measured athletes.

Read the evidenceHide the evidence

Does training the gap work?

Jiménez-Reyes et al. 2017 split 84 people into an individualised group (sorted into force-deficit, velocity-deficit and well-balanced), a standard strength program and a control group. After 9 weeks, the individualised training improved jumping performance more than the program that treated everyone the same.

Participants

84

Assigned to individualised, standard or control groups.

Program

9 weeks

Resistance training aimed at each person's profile, or at no one in particular.

Result

Targeted won

Training to the profile improved jump performance more than standard training.

Worth knowing: Bobbert et al. 2023 used simulation models to test what the jump profile actually measures. Their conclusion: it describes how an athlete performs that particular jumping task, and it doesn't represent the muscles' own force-velocity relationship. Its maximum force and maximum velocity also aren't independent of each other. Use a profile to guide what to train next, not as a diagnosis of the athlete's muscles.
04

Velocity Zones

Bryan Mann's five zones split the curve by bar speed, from slow and heavy to fast and light. They're the most widely used VBT shorthand, and they're a coaching framework, not thresholds tested in a trial.

Below 0.5 m/s

Near-maximal loads that move slowly however hard the athlete pushes. This is where the 1RM gets built.

0.5 to 0.75 m/s

Heavy loads driven as fast as possible. Heavy enough to build strength, fast enough to train intent.

0.75 to 1.0 m/s

Moderate loads, where power work begins. Strength comes first and speed second.

1.0 to 1.3 m/s

Lighter loads moved fast. Speed comes first and strength second.

Above 1.3 m/s

Very light or unloaded, all about overcoming inertia quickly from a standstill.

Worth knowing: the zones were written around mean velocity in lifts like the squat, and they don't travel well. Weakley et al. 2026 profiled seven weightlifting derivatives using peak velocity and found every one moved faster than 1.3 m/s at loads above 80% of 1RM. By the standard bands, that heavy work would read as "starting strength". Use the zones for squat-pattern lifts, and build exercise-specific profiles for the Olympic lifts.

Programming Notes

Every number on this page assumes the athlete is trying to move the bar as fast as possible on every rep. Sánchez-Medina et al. 2017 found that, under that condition, the first rep of a set already gives a good estimate of relative load in the full squat. A rep done at a comfortable tempo tells you nothing about load.

The link between bar speed and %1RM also holds as an athlete gets stronger. In González-Badillo and Sánchez-Medina 2010, the bench press relationship stayed stable after six weeks of training lifted 1RM. That's the practical case for VBT: the profile updates every session, while a percentage chart goes stale between tests.

Keep the inputs consistent. The same device, the same velocity measure (mean, mean propulsive or peak, never mixed) and the same range of motion. Warm-up sets double as the profile, so it costs nothing extra in session time.

Every rep at full intent, or the velocity means nothing.

Same device, same lift, same depth, every time.

Stop the set at the cut-off, not at failure.

What this research can't tell you

Most of the load-velocity and velocity-loss research recruited young men. Of the lifts in the calculator, only the free-weight back squat has a separate published threshold for women, and the Smith machine study found women moved slower at 1RM than men. The thresholds are group averages with real spread between people. The power clean estimate is the weakest of the set: in the study behind it, the error was too large to track strength changes. The trials measured squat strength, jump height and muscle size, not race times or sprint performance.

The force-velocity material comes mainly from jumping. Profiles are specific to the task they're measured in, so a squat-jump profile doesn't tell you an athlete's sprint profile. The velocity zones are a coaching framework rather than a tested prescription.

This is general advice based on research and guidelines, and it doesn't replace correct coaching or periodisation for your athletes. Warm up properly before any heavy or fast session: see the RAMP Warm-Up guide.

References

Figures and citations checked against the published papers, October 2026.

Cat Hoh
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