Force-Velocity Profile Individualization Guide: The Science of Athlete-Specific Power Prescription

One of the greatest advances in modern sports science is the shift from ‘same prescription for all athletes’ to ‘prescription tailored to individual profiles.’ At the heart of this shift is Force-Velocity (F-V) profiling. Two athletes with identical vertical jump heights can have entirely different limitations—one lacking force, the other lacking velocity. Without diagnosing this difference, training becomes inefficient or even counterproductive.

Research by Samozino et al. (2014, 2018) demonstrated that the degree of deviation from the ‘optimal slope’ of the F-V profile directly correlates with jump performance. In other words, it’s not simply about being strong or fast—the balance between the two variables matters, and when this balance is broken, targeted training is needed to restore it. The 800Hz IMU sensor is the key technology that has made this diagnosis possible in the field.

This guide comprehensively covers F-V profiling from theoretical foundation to measurement protocols, prescription by imbalance type, and practical case studies. Written as an immediately applicable manual for coaches and trainers using PoinT GO, it presents methods to obtain accurate athlete profiles in a 30-minute measurement session.

The F-V profile is a graph expressing the relationship between force and velocity an athlete produces under various load conditions as a straight line. Theoretically, all human muscles show a linear (or near-linear) relationship where higher loads result in slower velocities. The slope of this line, Y-intercept (theoretical maximum force F0), X-intercept (theoretical maximum velocity V0), and maximum power (Pmax) are the key variables.

An FVimb value of 100% means perfect balance, below 100% indicates Force-Deficit, and above 100% indicates Velocity-Deficit profile. Generally, values outside the 60~140% range are classified as clear imbalances requiring targeted training. The load-velocity profile guide provides additional context.

To accurately measure F-V profiles, you must perform exercises at a minimum of 4~6 different loads and measure the mean concentric velocity at each load. The 800Hz IMU sensor enables this work to be done quickly and accurately in the field.

The standard jump squat F-V profiling protocol: 1) thorough warm-up, 2) 3 jump squats with body weight only, 3) 3 reps each at 25%, 50%, 75%, 100% body weight loads, 4) use the highest velocity value at each load, 5) F-V curve regression analysis. The entire process takes 30~45 minutes.

Bench press upper body F-V profiling can be performed on the same principle. Measure 1~3 reps at 30%, 45%, 60%, 75%, 90% of 1RM, then linearly regress the relationship between mean velocity and load. A wider load range than jump squat is needed for an accurate curve.

Measurement precautions: 1) sufficient rest between sets (3~5 minutes), 2) emphasize maximal effort each attempt, 3) maintain depth/posture consistency, 4) same conditions (same time of day) recommended. Without these conditions, regression line reliability drops dramatically.

Once F-V imbalance is diagnosed, clearly differentiated training prescriptions must be applied based on the type.

For example, an athlete with FVimb of 55% (severe force deficit) should focus on improving back squat 1RM and reduce explosive exercises like hex bar jump squat. Conversely, an athlete with FVimb of 150% (severe velocity deficit) should prioritize bodyweight or low-load jumps and medicine ball throws.

After prescription, retest every 4~6 weeks to track FVimb changes. The goal is typically to move FVimb into the balanced range within 8~12 weeks.

Two cases applying theory to practice demonstrate the value of F-V individualization.

Case 1: 18-year-old basketball guard, jump improvement goal. Initial measurement: vertical jump 58cm, FVimb 142% (velocity deficit). Targeted training: 0~25% load jump squats, box jumps, CMJ-focused 8-week program. After 8 weeks: FVimb 118%, vertical jump improved to 64cm. Despite no significant change in back squat 1RM during the same period, jump ability improved by 6cm.

Case 2: 24-year-old rugby forward, collision force improvement goal. Initial measurement: FVimb 68% (force deficit). Targeted training: back squat, deadlift, 70~90% 1RM-focused 8-week program. After 8 weeks: FVimb 91%, back squat 1RM increased from 165kg to 182kg, scrum collision force measurement showed average 14% improvement.

The commonality of these two cases is clear. If both athletes had received the same training, one would have benefited and the other would have plateaued. Only targeted training based on individual F-V profiles creates true efficiency.