Velocity based training (VBT) has become a popular tool for prescribing and monitoring intensity/volume for traditional resistance training (TRT) exercises among strength and conditioning coaches. Although there are many methods that you may utilize VBT, one of the most common implementations is velocity zones. Velocity zones are based on the inverse relationship between force and velocity in TRT (Figure 1) (5).  It has been reported that movement velocity has a strong relationship with the % of 1 repetition maximum (1RM) of a given resistance training exercise (1).  For instance, when your athlete approaches their 1RM the speed of their movement decreases. By using movement velocity, it may help you account for your athletes’ daily fluctuations in fatigue or readiness.

Figure 1. Force-velocity curve (2)

Researchers and practitioners have categorized the velocity of movement and its associated % of 1RM into velocity zones based upon specific strength qualities (Table 1).  These velocity zones can assist you in adequately prescribing intensity to yield a specific strength quality.  For instance, in a strength speed phase you may stay within a velocity of .75 - .50 m/s for a given movement throughout that training phase.  Like everything in the strength field, slightly different zone ranges and terminology have been used, however the implementation of velocity zones in a TRT program has been shown to elicit adaptations in body composition and performance assessments (5).

Table 1. Velocity Zones for TRT Exercises

Limited training load parameters exist for flywheel resistance training (FRT). One possible reason for this is with flywheel technology, it is not possible to determine a true 1RM as shown in TRT since there is not a maximum load that can be lifted. Rather, an athlete needs to accelerate the flywheel during the concentric phase, which then returns the stored energy during the following eccentric phase (3). Where FRT does not differ from TRT is the relationship between load and movement velocity (4), and it is generally thought that lighter inertial loads (smaller plates as in little blue and yellow) will favor velocity-based adaptations, whereas heavier inertial loads (large plates as in big red) will favor strength-based adaptations (Figure 2). Given this, the use of velocity zone thresholds is a potentially viable method and useful way for you to prescribe and monitor intensity during flywheel exercises.

Figure 2. Force velocity curve with inertia loads

The implementation of velocity zone thresholds and FRT can be implemented in the same manner as TRT, in which the speed of the movement should match the desired strength quality. For instance, if the desired strength quality is strength speed, you can prescribe a load in which an athlete is able to stay within a mean concentric velocity between .75 - .50 m/s. Let’s take the inertial load-velocity profiles of the 2 athletes depicted in Figure 3 as an example. The corresponding load for Athlete 1 would be roughly .075 - .175 kg m² inertial load, whereas for a stronger athlete, Athlete 2, this corresponding load would occur at approximately .125 - .250 kg m². Building out an inertial load-velocity profile is a great road map for prescribing an appropriate load for individual athletes. This inertial load-velocity profile may also provide you with insight on the athlete’s fatigue status based upon the movement velocity at a respective load and subsequently aid in workload management. I discussed building out an inertial load-velocity profile in my previous blog post, and for further information on this please visit it here.

Figure 3. Comparison of Inertial load-velocity profile for 2 athletes

Thanks to a recently added feature the Exerfly app, users can now easily set velocity zones. This new feature will allow you to set the predetermined upper and lower velocity limits of the zone that you would like to train in during a set. During the set, the app will dynamically update following each repetition and alert you if the athlete falls above or below the zone. Depicted in Figure 4 is Athlete 2 performing a squat of 6 reps with a strength speed velocity zone (0.75 – 0.50 m/s). As you may be able to see the athlete superseded the upper limit, .75 m/s of this zone during the first 2 repetitions. In this instance, we increased the load to .15 kg m² in the subsequent set to more adequately train the desired strength quality. Not only can you monitor this in the depicted graph, but you can also monitor this in table view. Additionally, the velocity zone setting can be customizable to allow you to apply other kinematic variables such as force or acceleration.

Figure 4: Velocity zones on the Exerfly app (Desktop version)

In conclusion

Velocity zones have been shown to elicit favorable adaptations in performance assessments and can be used to ensure an athlete is working at a stable intensity. Due to flywheel training showing a similar inverse relationship between movement speed and load, velocity zones are a potentially valid method of monitoring and prescribing training load. These zones can be easily implemented into your program by means of the Exerfly app and can be dynamically monitored in multiple views.

References

1. Banyard, HG, Nosaka, K, and Haff, GG. Reliability and validity of the load–velocity relationship to predict the 1rm back squat: J Strength Cond Res 31: 1897–1904, 2017.
2. Jensen, AM. The use of neuro emotional technique with competitive rowers: A case series. J Chiropr Med 10: 111–117, 2011.
3. Maroto-Izquierdo, S, Raya-González, J, Hernández-Davó, JL, and Beato, M. Load quantification and testing using flywheel devices in sports. Front Physiol 12: 739399, 2021.
4. Martín-Rivera, F, Beato, M, Alepuz-Moner, V, and Maroto-Izquierdo, S. Use of concentric linear velocity to monitor flywheel exercise load. Front Physiol 13: 961572, 2022.
5. Włodarczyk, M, Adamus, P, Zieliński, J, and Kantanista, A. Effects of velocity-based training on strength and power in elite athletes—a systematic review. IJERPH 18: 5257, 2021.